kotlin work part. 1

160 files changed, 7486 insertions, 8555 deletions

diff --git a/app/app.iml b/app/app.iml
index ad948429..731bc1c8 100644
--- a/app/app.iml
+++ b/app/app.iml
@@ -21,12 +21,30 @@
         <option name="ASSETS_FOLDER_RELATIVE_PATH" value="/src/main/assets" />
       </configuration>
     </facet>
+    <facet type="kotlin-language" name="Kotlin">
+      <configuration version="3" platform="JVM 1.8" useProjectSettings="false">
+        <compilerSettings />
+        <compilerArguments>
+          <option name="jvmTarget" value="1.8" />
+          <option name="languageVersion" value="1.1" />
+          <option name="apiVersion" value="1.0" />
+          <option name="pluginOptions">
+            <array />
+          </option>
+          <option name="pluginClasspaths">
+            <array />
+          </option>
+          <option name="version" value="true" />
+        </compilerArguments>
+      </configuration>
+    </facet>
   </component>
   <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
     <output url="file://$MODULE_DIR$/build/intermediates/classes/debug" />
     <output-test url="file://$MODULE_DIR$/build/intermediates/classes/test/debug" />
     <exclude-output />
     <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/kapt/debug" isTestSource="false" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/debug" isTestSource="false" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/debug" isTestSource="false" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/debug" isTestSource="false" generated="true" />
@@ -34,6 +52,8 @@
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/apt/debug" isTestSource="false" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/debug" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/res/resValues/debug" type="java-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/kapt/debugUnitTest" isTestSource="true" generated="true" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/kapt/debugAndroidTest" isTestSource="true" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/androidTest/debug" isTestSource="true" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/androidTest/debug" isTestSource="true" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/androidTest/debug" isTestSource="true" generated="true" />
@@ -62,13 +82,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
@@ -76,6 +89,13 @@
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/assets" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/bundles" />
@@ -94,6 +114,7 @@
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/sourceFolderJavaResources" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/symbols" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/transforms" />
+      <excludeFolder url="file://$MODULE_DIR$/build/kotlin" />
       <excludeFolder url="file://$MODULE_DIR$/build/outputs" />
       <excludeFolder url="file://$MODULE_DIR$/build/tmp" />
     </content>
@@ -106,6 +127,7 @@
     <orderEntry type="library" exported="" name="support-core-ui-25.3.1" level="project" />
     <orderEntry type="library" exported="" name="crashlytics-core-2.3.17" level="project" />
     <orderEntry type="library" exported="" name="antlr4-runtime-4.6" level="project" />
+    <orderEntry type="library" exported="" name="kotlin-stdlib-jre7-1.1.51" level="project" />
     <orderEntry type="library" exported="" name="support-v13-25.3.1" level="project" />
     <orderEntry type="library" exported="" name="rxandroid-2.0.1" level="project" />
     <orderEntry type="library" exported="" name="twitter4j-stream-4.0.6" level="project" />
@@ -115,8 +137,10 @@
     <orderEntry type="library" exported="" name="support-fragment-25.3.1" level="project" />
     <orderEntry type="library" exported="" name="reactive-streams-1.0.0" level="project" />
     <orderEntry type="library" exported="" name="fabric-1.3.17" level="project" />
+    <orderEntry type="library" exported="" name="annotations-13.0" level="project" />
     <orderEntry type="library" exported="" name="beta-1.2.5" level="project" />
     <orderEntry type="library" exported="" name="answers-1.3.13" level="project" />
+    <orderEntry type="library" exported="" name="kotlin-stdlib-1.1.51" level="project" />
     <orderEntry type="library" exported="" name="support-v4-25.3.1" level="project" />
     <orderEntry type="library" exported="" name="support-media-compat-25.3.1" level="project" />
     <orderEntry type="library" exported="" name="volley-1.0.0" level="project" />
diff --git a/app/build.gradle b/app/build.gradle
index c8100f59..530700ca 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,4 +1,6 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-kapt'
 apply plugin: 'me.tatarka.retrolambda'
 apply plugin: 'io.fabric'
 
@@ -53,6 +55,8 @@ android {
 }
 
 dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
+
     compile 'com.android.support:support-v4:25.+'
     compile 'com.android.support:support-v13:25.+'
     // volley
@@ -71,7 +75,7 @@ dependencies {
     // twitter-text
     compile 'com.twitter:twitter-text:1.14.7'
 
-    annotationProcessor "com.github.gfx.android.orma:orma-processor:4.2.5"
+    kapt "com.github.gfx.android.orma:orma-processor:4.2.5"
     compile "com.github.gfx.android.orma:orma:4.2.5"
 
     // Fabric
@@ -80,8 +84,10 @@ dependencies {
     }
 
     // LeakCanary
-
     debugCompile 'com.squareup.leakcanary:leakcanary-android:1.5.4'
     releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.4'
     release2Compile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.4'
+}
+repositories {
+    mavenCentral()
 }
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/Application.java b/app/src/main/java/net/lacolaco/smileessence/Application.java
deleted file mode 100644
index adefcae1..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/Application.java
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence;
-
-import android.support.annotation.StringRes;
-import android.widget.Toast;
-import com.crashlytics.android.Crashlytics;
-import com.crashlytics.android.core.CrashlyticsCore;
-import com.squareup.leakcanary.LeakCanary;
-import io.fabric.sdk.android.Fabric;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.OrmaHolder;
-import net.lacolaco.smileessence.logging.Logger;
-
-import java.lang.ref.WeakReference;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * プロセスと同期しているオブジェクト
- * 現在のテーマのリソース ID と現在のアカウント（およびアカウント変更イベントリスナー）を保持します
- * MainActivity の onCreate で resetState を呼び、保持しているデータを破棄すること
- */
-public class Application extends android.app.Application {
-    private static Application instance;
-    private static WeakReference<World> lastWorld;
-    private static Map<Long, WeakReference<World>> worlds = new HashMap<>(); // XXX
-
-    @Deprecated
-    public static Application getInstance() {
-        Application obj = instance;
-        if (obj == null) {
-            throw new IllegalStateException("[BUG] Application is not initialized?");
-        } else {
-            return obj;
-        }
-    }
-
-    // --------------------- get instance ---------------------
-
-    public static void toast(@StringRes int id) {
-        Toast.makeText(instance, id, Toast.LENGTH_LONG).show();
-    }
-
-    public static void toast(String text) {
-        Toast.makeText(instance, text, Toast.LENGTH_LONG).show();
-    }
-
-    @Override
-    public void onCreate() {
-        super.onCreate();
-        if (LeakCanary.isInAnalyzerProcess(this)) {
-            return;
-        }
-        LeakCanary.install(this);
-
-        Fabric.with(this, new Crashlytics.Builder().core(new CrashlyticsCore.Builder().disabled(BuildConfig.DEBUG).build()).build());
-        OrmaHolder.initialize(this);
-
-        // Load eagarly
-        Account.load();
-        instance = this; // プロセスの寿命の間 1 度しか呼ばれないので安全
-        Logger.debug("onCreate");
-    }
-
-    public static World getCurrentWorld() {
-        World w0 = lastWorld != null ? lastWorld.get() : null;
-        if (w0 != null)
-            return w0;
-        for (WeakReference<World> ww : worlds.values()) {
-            World w = ww.get();
-            if (w != null)
-                return w;
-        }
-        return null;
-    }
-
-    public static World getWorld(long id) {
-        WeakReference<World> ww = worlds.get(id);
-        if (ww != null) {
-            World w = ww.get();
-            if (w != null) {
-                lastWorld = ww;
-                return w;
-            }
-        }
-        World w = new World(Account.get(id));
-        worlds.put(id, lastWorld = new WeakReference<>(w));
-        return w;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/Application.kt b/app/src/main/java/net/lacolaco/smileessence/Application.kt
new file mode 100644
index 00000000..7950d62a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/Application.kt
@@ -0,0 +1,112 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence
+
+import android.support.annotation.StringRes
+import android.widget.Toast
+import com.crashlytics.android.Crashlytics
+import com.crashlytics.android.core.CrashlyticsCore
+import com.squareup.leakcanary.LeakCanary
+import io.fabric.sdk.android.Fabric
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.data.OrmaHolder
+import net.lacolaco.smileessence.logging.Logger
+
+import java.lang.ref.WeakReference
+import java.util.HashMap
+
+/**
+ * プロセスと同期しているオブジェクト
+ * 現在のテーマのリソース ID と現在のアカウント（およびアカウント変更イベントリスナー）を保持します
+ * MainActivity の onCreate で resetState を呼び、保持しているデータを破棄すること
+ */
+class Application : android.app.Application() {
+
+    override fun onCreate() {
+        super.onCreate()
+        if (LeakCanary.isInAnalyzerProcess(this)) {
+            return
+        }
+        LeakCanary.install(this)
+
+        Fabric.with(this, Crashlytics.Builder().core(CrashlyticsCore.Builder().disabled(BuildConfig.DEBUG).build()).build())
+        OrmaHolder.initialize(this)
+
+        // Load eagarly
+        Account.load()
+        instancex = this // プロセスの寿命の間 1 度しか呼ばれないので安全
+        Logger.debug("onCreate")
+    }
+
+    companion object {
+        private var instancex: Application? = null
+        private var lastWorld: WeakReference<World>? = null
+        private val worlds = HashMap<Long, WeakReference<World>>() // XXX
+
+        @Deprecated("")
+        fun getInstance(): Application {
+            val obj = instancex
+            return obj ?: throw IllegalStateException("[BUG] Application is not initialized?")
+        }
+
+        // --------------------- get instance ---------------------
+
+        fun toast(@StringRes id: Int) {
+            Toast.makeText(instancex, id, Toast.LENGTH_LONG).show()
+        }
+
+        fun toast(text: String) {
+            Toast.makeText(instancex, text, Toast.LENGTH_LONG).show()
+        }
+
+        val currentWorld: World?
+            get() {
+                val w0 = if (lastWorld != null) lastWorld!!.get() else null
+                if (w0 != null)
+                    return w0
+                for (ww in worlds.values) {
+                    val w = ww.get()
+                    if (w != null)
+                        return w
+                }
+                return null
+            }
+
+        fun getWorld(id: Long): World {
+            val ww0 = worlds[id]
+            if (ww0 != null) {
+                val w0 = ww0.get()
+                if (w0 != null) {
+                    lastWorld = ww0
+                    return w0
+                }
+            }
+            val w = World(Account.get(id))
+            val ww = WeakReference(w)
+            worlds.put(id, ww)
+            return w
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/IntentRouter.java b/app/src/main/java/net/lacolaco/smileessence/IntentRouter.java
deleted file mode 100644
index 84e41ff6..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/IntentRouter.java
+++ /dev/null
@@ -1,143 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence;
-
-import android.app.Activity;
-import android.content.Intent;
-import android.net.Uri;
-import android.os.Bundle;
-import android.text.TextUtils;
-import android.widget.Toast;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.command.CommandOpenUserDetail;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.dialog.StatusDetailDialogFragment;
-
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-public class IntentRouter {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private static final String TWITTER_HOST = "twitter.com";
-    private static final Pattern TWITTER_STATUS_PATTERN = Pattern.compile("\\A(?:/#!)?/(?:\\w{1,15})/status(?:es)?/(\\d+)\\z", Pattern.CASE_INSENSITIVE);
-    private static final Pattern TWITTER_USER_PATTERN = Pattern.compile("\\A(?:/#!)?/(\\w{1,15})/?\\z", Pattern.CASE_INSENSITIVE);
-    private static final Pattern TWITTER_POST_PATTERN = Pattern.compile("\\A/(intent/tweet|share)\\z", Pattern.CASE_INSENSITIVE);
-
-    // -------------------------- STATIC METHODS --------------------------
-
-    public static void onNewIntent(MainActivity activity, Intent intent) {
-        Logger.debug("onNewIntent");
-        Uri uri = intent.getData();
-        if (uri != null) {
-            onUriIntent(activity, uri);
-        } else if (intent.getAction() != null) {
-            switch (intent.getAction()) {
-                case Intent.ACTION_SEND: {
-                    if ("text/plain".equals(intent.getType())) {
-                        Bundle extra = intent.getExtras();
-                        if (extra != null) {
-                            String text = getText(extra);
-                            openPostPage(activity, text);
-                        }
-                    } else if (intent.getType().startsWith("image/")) {
-                        Uri imageUri = intent.getParcelableExtra(Intent.EXTRA_STREAM);
-                        openPostPageWithImage(activity, imageUri);
-                    }
-                    break;
-                }
-            }
-        }
-    }
-
-    private static void onUriIntent(MainActivity activity, Uri uri) {
-        Logger.debug(uri.toString());
-
-        if (uri.getHost().equals(TWITTER_HOST)) {
-            Matcher postMatcher = TWITTER_POST_PATTERN.matcher(uri.getPath()); // /share and /intent/tweet: don't accept status parameter
-            if (postMatcher.find()) {
-                openPostPage(activity, extractText(uri));
-                return;
-            }
-            Matcher statusMatcher = TWITTER_STATUS_PATTERN.matcher(uri.getPath());
-            if (statusMatcher.find()) {
-                showStatusDialog(activity, Long.parseLong(statusMatcher.group(1)));
-                return;
-            }
-            Matcher userMatcher = TWITTER_USER_PATTERN.matcher(uri.getPath());
-            if (userMatcher.find()) {
-                showUserDialog(activity, userMatcher.group(1));
-            }
-        }
-    }
-
-    private static String getText(Bundle extra) {
-        StringBuilder builder = new StringBuilder();
-        if (!TextUtils.isEmpty(extra.getCharSequence(Intent.EXTRA_SUBJECT))) {
-            builder.append(extra.getCharSequence(Intent.EXTRA_SUBJECT)).append(" ");
-        }
-        builder.append(extra.getCharSequence(Intent.EXTRA_TEXT));
-        return builder.toString();
-    }
-
-    private static String extractText(Uri uri) {
-        String result = "";
-        String text = uri.getQueryParameter("text");
-        String url = uri.getQueryParameter("url");
-        String via = uri.getQueryParameter("via");
-        String hashtags = uri.getQueryParameter("hashtags");
-
-        if (!TextUtils.isEmpty(text)) result += text;
-        if (!TextUtils.isEmpty(url)) result += " " + url;
-        if (!TextUtils.isEmpty(hashtags)) result += " " + hashtags.trim().replaceAll(",", " #");
-        if (!TextUtils.isEmpty(via)) result += " via @" + via;
-
-        return result;
-    }
-
-    private static void showStatusDialog(Activity activity, long id) {
-        Tweet.fetchTask(id, Application.getCurrentWorld().getAccount())
-                .onDoneUI(tweet -> DialogHelper.showDialog(activity, StatusDetailDialogFragment.newInstance(tweet)))
-                .onFail(x -> Application.toast(R.string.error_intent_status_cannot_load))
-                .execute();
-    }
-
-    private static void showUserDialog(MainActivity activity, String screenName) {
-        CommandOpenUserDetail openUserDetail = new CommandOpenUserDetail(activity, screenName);
-        openUserDetail.execute();
-    }
-
-    private static void openPostPage(final MainActivity activity, final String str) {
-        new UIHandler().post(() -> activity.getWorld().getPostState().beginTransaction().setText(str).commitWithOpen(activity));
-    }
-
-    private static void openPostPageWithImage(final MainActivity activity, final Uri imageUri) {
-        new UIHandler().post(() -> activity.openPostPageWithImage(imageUri));
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/IntentRouter.kt b/app/src/main/java/net/lacolaco/smileessence/IntentRouter.kt
new file mode 100644
index 00000000..e5f9d0ce
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/IntentRouter.kt
@@ -0,0 +1,142 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence
+
+import android.app.Activity
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.text.TextUtils
+import android.widget.Toast
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.command.CommandOpenUserDetail
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.dialog.StatusDetailDialogFragment
+
+import java.util.regex.Matcher
+import java.util.regex.Pattern
+
+object IntentRouter {
+
+    // ------------------------------ FIELDS ------------------------------
+
+    private val TWITTER_HOST = "twitter.com"
+    private val TWITTER_STATUS_PATTERN = Pattern.compile("\\A(?:/#!)?/(?:\\w{1,15})/status(?:es)?/(\\d+)\\z", Pattern.CASE_INSENSITIVE)
+    private val TWITTER_USER_PATTERN = Pattern.compile("\\A(?:/#!)?/(\\w{1,15})/?\\z", Pattern.CASE_INSENSITIVE)
+    private val TWITTER_POST_PATTERN = Pattern.compile("\\A/(intent/tweet|share)\\z", Pattern.CASE_INSENSITIVE)
+
+    // -------------------------- STATIC METHODS --------------------------
+
+    fun onNewIntent(activity: MainActivity, intent: Intent) {
+        Logger.debug("onNewIntent")
+        val uri = intent.data
+        if (uri != null) {
+            onUriIntent(activity, uri)
+        } else if (intent.action != null) {
+            when (intent.action) {
+                Intent.ACTION_SEND -> {
+                    if ("text/plain" == intent.type) {
+                        val extra = intent.extras
+                        if (extra != null) {
+                            val text = getText(extra)
+                            openPostPage(activity, text)
+                        }
+                    } else if (intent.type.startsWith("image/")) {
+                        val imageUri = intent.getParcelableExtra<Uri>(Intent.EXTRA_STREAM)
+                        openPostPageWithImage(activity, imageUri)
+                    }
+                }
+            }
+        }
+    }
+
+    private fun onUriIntent(activity: MainActivity, uri: Uri) {
+        Logger.debug(uri.toString())
+
+        if (uri.host == TWITTER_HOST) {
+            val postMatcher = TWITTER_POST_PATTERN.matcher(uri.path) // /share and /intent/tweet: don't accept status parameter
+            if (postMatcher.find()) {
+                openPostPage(activity, extractText(uri))
+                return
+            }
+            val statusMatcher = TWITTER_STATUS_PATTERN.matcher(uri.path)
+            if (statusMatcher.find()) {
+                showStatusDialog(activity, java.lang.Long.parseLong(statusMatcher.group(1)))
+                return
+            }
+            val userMatcher = TWITTER_USER_PATTERN.matcher(uri.path)
+            if (userMatcher.find()) {
+                showUserDialog(activity, userMatcher.group(1))
+            }
+        }
+    }
+
+    private fun getText(extra: Bundle): String {
+        val builder = StringBuilder()
+        if (!TextUtils.isEmpty(extra.getCharSequence(Intent.EXTRA_SUBJECT))) {
+            builder.append(extra.getCharSequence(Intent.EXTRA_SUBJECT)).append(" ")
+        }
+        builder.append(extra.getCharSequence(Intent.EXTRA_TEXT))
+        return builder.toString()
+    }
+
+    private fun extractText(uri: Uri): String {
+        var result = ""
+        val text = uri.getQueryParameter("text")
+        val url = uri.getQueryParameter("url")
+        val via = uri.getQueryParameter("via")
+        val hashtags = uri.getQueryParameter("hashtags")
+
+        if (!TextUtils.isEmpty(text)) result += text
+        if (!TextUtils.isEmpty(url)) result += " " + url
+        if (!TextUtils.isEmpty(hashtags)) result += " " + hashtags.trim { it <= ' ' }.replace(",".toRegex(), " #")
+        if (!TextUtils.isEmpty(via)) result += " via @" + via
+
+        return result
+    }
+
+    private fun showStatusDialog(activity: Activity, id: Long) {
+        Tweet.fetchTask(id, Application.currentWorld!!.account)
+                .onDoneUI { tweet -> DialogHelper.showDialog(activity, StatusDetailDialogFragment.newInstance(tweet)) }
+                .onFail { x -> Application.toast(R.string.error_intent_status_cannot_load) }
+                .execute()
+    }
+
+    private fun showUserDialog(activity: MainActivity, screenName: String) {
+        val openUserDetail = CommandOpenUserDetail(activity, screenName)
+        openUserDetail.execute()
+    }
+
+    private fun openPostPage(activity: MainActivity, str: String) {
+        UIHandler().post { activity.world.postState.beginTransaction().setText(str).commitWithOpen(activity) }
+    }
+
+    private fun openPostPageWithImage(activity: MainActivity, imageUri: Uri) {
+        UIHandler().post { activity.openPostPageWithImage(imageUri) }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/World.java b/app/src/main/java/net/lacolaco/smileessence/World.java
deleted file mode 100644
index ae9c68cd..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/World.java
+++ /dev/null
@@ -1,252 +0,0 @@
-package net.lacolaco.smileessence;
-
-import android.content.Context;
-import android.support.annotation.StringRes;
-import de.keyboardsurfer.android.widget.crouton.Configuration;
-import de.keyboardsurfer.android.widget.crouton.Crouton;
-import de.keyboardsurfer.android.widget.crouton.Style;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.PostState;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.entity.Event;
-import net.lacolaco.smileessence.entity.SavedSearch;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.twitter.UserStreamListener;
-import net.lacolaco.smileessence.twitter.task.Accounts;
-import net.lacolaco.smileessence.twitter.task.Searches;
-import net.lacolaco.smileessence.twitter.task.Users;
-import net.lacolaco.smileessence.util.*;
-import twitter4j.TwitterStream;
-
-import java.lang.ref.WeakReference;
-import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
-
-/**
- * World contains data that are specific to an account.
- */
-public class World {
-    private static final int NOTIFICATION_DURATION = 1000;
-    private Account account;
-    private int resId; // XXX: Fetch from Account
-    // XXX: Move to MainActivity
-    private PostState postState = new PostState();
-    // Timelines
-    private final List<Tweet> tweets = new ArrayList<>();
-    private final WeakHashMap<Object, Consumer<Tweet>> tweetNotifiers = new WeakHashMap<>();
-    // Direct messages
-    private final Map<Long, DirectMessage> directMessages = new ConcurrentHashMap<>();
-    private final WeakHashMap<Object, Consumer<DirectMessage>> directMessageNotifiers = new WeakHashMap<>();
-    // Events
-    private final List<Event> events = new ArrayList<>();
-    private final WeakHashMap<Object, Runnable> eventNotifiers = new WeakHashMap<>();
-    // Streaming APIs
-    private TwitterStream stream;
-    private UserStreamListener userStreamListener;
-    // Lists
-    private final Set<String> listSubscriptions = Collections.newSetFromMap(new ConcurrentHashMap<>());
-    // Mute
-    private final Set<Long> muteUserIds = Collections.newSetFromMap(new ConcurrentHashMap<>());
-    // Saved searches
-    private final Map<Long, SavedSearch> savedSearches = new HashMap<>();
-    // Notification
-    private WeakReference<MainActivity> mainActivity;
-    private boolean isMainActivityActive;
-
-    public World(Account a) {
-        account = a;
-    }
-
-    public Account getAccount() {
-        return account;
-    }
-
-    @Deprecated
-    public void setAccount(Account a) {
-        account = a;
-    }
-
-    public PostState getPostState() {
-        return postState;
-    }
-
-    // Timelines
-
-    public synchronized void addTimeline(Object key, Consumer<Tweet> notify) {
-        for (Tweet tweet : tweets)
-            notify.accept(tweet);
-        tweetNotifiers.put(key, notify);
-    }
-
-    public synchronized void addTweet(Tweet tweet) {
-        tweets.add(tweet);
-        tweetNotifiers.forEach((o, c) -> c.accept(tweet));
-    }
-
-    public synchronized void addTweetAll(Collection<Tweet> ts) {
-        tweets.addAll(ts);
-        for (Tweet tweet : ts) {
-            tweetNotifiers.forEach((o, c) -> c.accept(tweet));
-        }
-    }
-
-    // Direct messages
-
-    public synchronized void addDirectMessageTimeline(Object key, Consumer<DirectMessage> notify) {
-        directMessageNotifiers.put(key, notify);
-    }
-
-    public void addDirectMessage(DirectMessage entity) {
-        if (directMessages.put(entity.getId(), entity) == null)
-            directMessageNotifiers.forEach((o, c) -> c.accept(entity));
-    }
-
-    // Events
-
-    public synchronized void addEventNotifier(Object key, Runnable notify) {
-        eventNotifiers.put(key, notify);
-    }
-
-    public List<Event> getEvents() {
-        return events;
-    }
-
-    public void addEvent(Event e) {
-        events.add(e);
-        eventNotifiers.forEach((o, a) -> a.run());
-    }
-
-    // Streaming APIs
-
-    public void setupStreaming() {
-        if (stream == null) {
-            stream = account.getTwitterStream();
-            userStreamListener = new UserStreamListener(this);
-            stream.addListener(userStreamListener);
-            stream.addConnectionLifeCycleListener(userStreamListener);
-            stream.user();
-        }
-    }
-
-    public boolean isStreaming() {
-        return stream != null && userStreamListener.isConnected();
-    }
-
-    // Lists
-
-    public BackgroundTask<List<String>, Void> refreshListSubscriptions() {
-        return new Users.GetManyTask(account)
-                .onDone(lists -> {
-                    listSubscriptions.clear();
-                    listSubscriptions.addAll(lists);
-                })
-                // .onFail(x -> { }) // TODO: error message?
-                .execute();
-    }
-
-    public Set<String> getListSubscriptions() {
-        return listSubscriptions;
-    }
-
-    public boolean addListSubscription(String fullName) {
-        return listSubscriptions.add(fullName);
-    }
-
-    public boolean removeListSubscription(String fullName) {
-        return listSubscriptions.remove(fullName);
-    }
-
-    // Mute
-
-    public List<BackgroundTask> refreshUserMuteList() {
-        List<BackgroundTask> tasks = new ArrayList<>();
-        tasks.add(new Accounts.BlockIDsTask(account).onDone(muteUserIds::addAll).execute());
-        tasks.add(new Accounts.MutesIDsTask(account).onDone(muteUserIds::addAll).execute());
-        return tasks;
-    }
-
-    public boolean isMutedUserListContains(long id) {
-        return muteUserIds.contains(id);
-    }
-
-    // Saved search queries
-
-    public Collection<SavedSearch> getSavedSearches() {
-        return savedSearches.values();
-    }
-
-    public BackgroundTask<List<SavedSearch>, Void> refreshSavedSearches() {
-        return new Searches.GetAllSavedSearchesTask(account).onDone(ssl -> {
-            savedSearches.clear();
-            for (SavedSearch ss : ssl)
-                savedSearches.put(ss.getId(), ss);
-        }).execute();
-    }
-
-    // Notifications
-
-    public void setMainActivity(MainActivity activity) {
-        mainActivity = new WeakReference<>(activity);
-    }
-
-    public void setMainActivityActive(boolean yes) {
-        isMainActivityActive = yes;
-    }
-
-    public void notify(String text) {
-        doNotify(NotificationType.INFO, text);
-    }
-
-    public void notify(@StringRes int resId, Object... formatArgs) {
-        doNotify(NotificationType.INFO, resId, formatArgs);
-    }
-
-    public void notifyError(String text) {
-        doNotify(NotificationType.ALERT, text);
-    }
-
-    public void notifyError(@StringRes int resId, Object... formatArgs) {
-        doNotify(NotificationType.ALERT, resId, formatArgs);
-    }
-
-    private void doNotify(NotificationType type, @StringRes int resId, Object... formatArgs) {
-        Context context = mainActivity.get();
-        if (context != null) {
-            String text = context.getString(resId, formatArgs);
-            doNotify(type, text);
-        } else {
-            Logger.debug("MainActivity is dead");
-        }
-    }
-
-    private void doNotify(NotificationType type, String text) {
-        MainActivity activity = mainActivity.get();
-        if (activity == null || activity.isFinishing()) {
-            Logger.debug(String.format("notify(log): %s", text));
-        } else {
-            new UIHandler().post(() -> {
-                if (isMainActivityActive) {
-                    Logger.debug(String.format("notify(crouton): %s", text));
-                    Configuration.Builder conf = new Configuration.Builder();
-                    conf.setDuration(NOTIFICATION_DURATION);
-                    Style.Builder bstyle = new Style.Builder();
-                    bstyle.setConfiguration(conf.build());
-                    bstyle.setBackgroundColorValue(type == NotificationType.ALERT ?
-                            Style.holoRedLight : Style.holoBlueLight);
-                    Crouton.makeText(activity, text, bstyle.build()).show();
-                } else {
-                    Logger.debug(String.format("notify(toast): %s", text));
-                    Application.toast(text);
-                }
-            });
-        }
-    }
-
-    enum NotificationType {
-        INFO,
-        ALERT
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/World.kt b/app/src/main/java/net/lacolaco/smileessence/World.kt
new file mode 100644
index 00000000..b18522e5
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/World.kt
@@ -0,0 +1,230 @@
+package net.lacolaco.smileessence
+
+import android.support.annotation.StringRes
+import de.keyboardsurfer.android.widget.crouton.Configuration
+import de.keyboardsurfer.android.widget.crouton.Crouton
+import de.keyboardsurfer.android.widget.crouton.Style
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.compat.Twitter4J
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.data.PostState
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.entity.Event
+import net.lacolaco.smileessence.entity.SavedSearch
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.twitter.UserStreamListener
+import net.lacolaco.smileessence.twitter.task.Accounts
+import net.lacolaco.smileessence.twitter.task.Searches
+import net.lacolaco.smileessence.twitter.task.Users
+import net.lacolaco.smileessence.util.*
+import twitter4j.TwitterStream
+
+import java.lang.ref.WeakReference
+import java.util.*
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * World contains data that are specific to an account.
+ */
+class World(var account: Account) {
+    private val resId: Int = 0 // XXX: Fetch from Account
+    // XXX: Move to MainActivity
+    val postState = PostState()
+    // Timelines
+    private val tweets = ArrayList<Tweet>()
+    private val tweetNotifiers = WeakHashMap<Any, (Tweet) -> Unit>()
+    // Direct messages
+    private val directMessages = ConcurrentHashMap<Long, DirectMessage>()
+    private val directMessageNotifiers = WeakHashMap<Any, (DirectMessage) -> Unit>()
+    // Events
+    val events = ArrayList<Event>()
+    private val eventNotifiers = WeakHashMap<Any, () -> Unit>()
+    // Streaming APIs
+    private var stream: TwitterStream? = null
+    private var userStreamListener: UserStreamListener? = null
+    // Lists
+    val listSubscriptions = Collections.newSetFromMap(ConcurrentHashMap<String, Boolean>())
+    // Mute
+    private val muteUserIds = Collections.newSetFromMap(ConcurrentHashMap<Long, Boolean>())
+    // Saved searches
+    val savedSearches = HashMap<Long, SavedSearch>()
+    // Notification
+    private var mainActivity: WeakReference<MainActivity>? = null
+    private var isMainActivityActive: Boolean = false
+
+    // Timelines
+
+    @Synchronized
+    fun addTimeline(key: Any, notify: (Tweet) -> Unit) {
+        for (tweet in tweets)
+            notify(tweet)
+        tweetNotifiers.put(key, notify)
+    }
+
+    @Synchronized
+    fun addTweet(tweet: Tweet) {
+        tweets.add(tweet)
+        tweetNotifiers.forEach { o, c -> c(tweet) }
+    }
+
+    @Synchronized
+    fun addTweetAll(ts: Collection<Tweet>) {
+        tweets.addAll(ts)
+        for (tweet in ts) {
+            tweetNotifiers.forEach { o, c -> c(tweet) }
+        }
+    }
+
+    // Direct messages
+
+    @Synchronized
+    fun addDirectMessageTimeline(key: Any, notify: (DirectMessage) -> Unit) {
+        directMessageNotifiers.put(key, notify)
+    }
+
+    fun addDirectMessage(entity: DirectMessage) {
+        if (directMessages.put(entity.id, entity) == null)
+            directMessageNotifiers.forEach { o, c -> c(entity) }
+    }
+
+    // Events
+
+    @Synchronized
+    fun addEventNotifier(key: Any, notify: () -> Unit) {
+        eventNotifiers.put(key, notify)
+    }
+
+    fun addEvent(e: Event) {
+        events.add(e)
+        eventNotifiers.forEach { o, a -> a() }
+    }
+
+    // Streaming APIs
+
+    fun setupStreaming() {
+        if (stream == null) {
+            stream = account.twitterStream
+            userStreamListener = UserStreamListener(this)
+            Twitter4J.twitterStreamAddListener(stream!!, userStreamListener!!)
+            stream!!.addConnectionLifeCycleListener(userStreamListener)
+            stream!!.user()
+        }
+    }
+
+    val isStreaming: Boolean
+        get() = stream != null && userStreamListener!!.isConnected
+
+    // Lists
+
+    fun refreshListSubscriptions(): BackgroundTask<List<String>, Void> {
+        return Users.GetManyTask(account)
+                .onDone { lists ->
+                    listSubscriptions.clear()
+                    listSubscriptions.addAll(lists)
+                }
+                // .onFail(x -> { }) // TODO: error message?
+                .execute()
+    }
+
+    fun addListSubscription(fullName: String): Boolean {
+        return listSubscriptions.add(fullName)
+    }
+
+    fun removeListSubscription(fullName: String): Boolean {
+        return listSubscriptions.remove(fullName)
+    }
+
+    // Mute
+
+    fun refreshUserMuteList(): List<BackgroundTask<*, *>> {
+        val tasks = ArrayList<BackgroundTask<*, *>>()
+        tasks.add(Accounts.BlockIDsTask(account).onDone { muteUserIds.addAll(it) }.execute())
+        tasks.add(Accounts.MutesIDsTask(account).onDone { muteUserIds.addAll(it) }.execute())
+        return tasks
+    }
+
+    fun isMutedUserListContains(id: Long): Boolean {
+        return muteUserIds.contains(id)
+    }
+
+    // Saved search queries
+
+    fun refreshSavedSearches(): BackgroundTask<List<SavedSearch>, Void> {
+        return Searches.GetAllSavedSearchesTask(account).onDone { ssl ->
+            savedSearches.clear()
+            for (ss in ssl)
+                savedSearches.put(ss.id, ss)
+        }.execute()
+    }
+
+    // Notifications
+
+    fun setMainActivity(activity: MainActivity) {
+        mainActivity = WeakReference(activity)
+    }
+
+    fun setMainActivityActive(yes: Boolean) {
+        isMainActivityActive = yes
+    }
+
+    fun notify(text: String) {
+        doNotify(NotificationType.INFO, text)
+    }
+
+    fun notify(@StringRes resId: Int, vararg formatArgs: Any) {
+        doNotify(NotificationType.INFO, resId, *formatArgs)
+    }
+
+    fun notifyError(text: String) {
+        doNotify(NotificationType.ALERT, text)
+    }
+
+    fun notifyError(@StringRes resId: Int, vararg formatArgs: Any) {
+        doNotify(NotificationType.ALERT, resId, *formatArgs)
+    }
+
+    private fun doNotify(type: NotificationType, @StringRes resId: Int, vararg formatArgs: Any) {
+        val context = mainActivity!!.get()
+        if (context != null) {
+            val text = context.getString(resId, *formatArgs)
+            doNotify(type, text)
+        } else {
+            Logger.debug("MainActivity is dead")
+        }
+    }
+
+    private fun doNotify(type: NotificationType, text: String) {
+        val activity = mainActivity!!.get()
+        if (activity == null || activity.isFinishing) {
+            Logger.debug(String.format("notify(log): %s", text))
+        } else {
+            UIHandler().post {
+                if (isMainActivityActive) {
+                    Logger.debug(String.format("notify(crouton): %s", text))
+                    val conf = Configuration.Builder()
+                    conf.setDuration(NOTIFICATION_DURATION)
+                    val bstyle = Style.Builder()
+                    bstyle.setConfiguration(conf.build())
+                    bstyle.setBackgroundColorValue(if (type == NotificationType.ALERT)
+                        Style.holoRedLight
+                    else
+                        Style.holoBlueLight)
+                    Crouton.makeText(activity, text, bstyle.build()).show()
+                } else {
+                    Logger.debug(String.format("notify(toast): %s", text))
+                    Application.toast(text)
+                }
+            }
+        }
+    }
+
+    internal enum class NotificationType {
+        INFO,
+        ALERT
+    }
+
+    companion object {
+        private val NOTIFICATION_DURATION = 1000
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.java
deleted file mode 100644
index 3876d506..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.java
+++ /dev/null
@@ -1,170 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.Activity;
-import android.os.Bundle;
-import android.support.v4.app.NavUtils;
-import android.text.TextUtils;
-import android.util.SparseBooleanArray;
-import android.view.*;
-import android.widget.AbsListView;
-import android.widget.ListView;
-import android.widget.TextView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.data.ExtractionWord;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-import net.lacolaco.smileessence.view.dialog.EditTextDialogFragment;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class EditExtractionActivity extends Activity implements AbsListView.MultiChoiceModeListener {
-    private List<ExtractionWord> list;
-    private CustomListAdapter<ExtractionWord> adapter;
-
-    private ListView getListView() {
-        return (ListView) findViewById(R.id.listview_edit_list);
-    }
-
-    @Override
-    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
-        menu.clear();
-        MenuInflater inflater = mode.getMenuInflater();
-        inflater.inflate(R.menu.edit_list, menu);
-        return true;
-    }
-
-    @Override
-    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
-        return false;
-    }
-
-    @Override
-    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.menu_edit_list_delete: {
-                deleteSelectedItems();
-            }
-        }
-        mode.finish();
-        return true;
-    }
-
-    @Override
-    public void onDestroyActionMode(ActionMode mode) {
-    }
-
-    @Override
-    public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
-    }
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        Logger.debug("onCreate");
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.layout_edit_list);
-
-        ListView listView = getListView();
-        list = new ArrayList<>();
-        adapter = new CustomListAdapter<ExtractionWord>() {
-            @Override
-            public View getView(int position, View convertView, ViewGroup parent) {
-                if (convertView == null) {
-                    convertView = EditExtractionActivity.this.getLayoutInflater().inflate(R.layout.list_item_simple_text, null);
-                }
-                TextView textView = (TextView) convertView.findViewById(R.id.list_item_textview);
-                textView.setText(getItem(position).getPatternString());
-                return convertView;
-            }
-
-            @Override
-            protected List<ExtractionWord> getList() {
-                return list;
-            }
-        };
-        list.addAll(ExtractionWord.cached());
-        adapter.update();
-        listView.setAdapter(adapter);
-        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
-        listView.setMultiChoiceModeListener(this);
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        MenuItem add = menu.add(Menu.NONE, R.id.menu_edit_list_add, Menu.NONE, "");
-        add.setIcon(android.R.drawable.ic_menu_add);
-        add.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
-        return true;
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.menu_edit_list_add: {
-                addNewExtractionWord();
-                break;
-            }
-            case android.R.id.home: {
-                NavUtils.navigateUpFromSameTask(this);
-                return true;
-            }
-        }
-        return true;
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    public void deleteSelectedItems() {
-        SparseBooleanArray checkedItems = getListView().getCheckedItemPositions();
-        for (int i = adapter.getCount() - 1; i > -1; i--) {
-            if (checkedItems.get(i)) {
-                ExtractionWord ew = adapter.getItem(i);
-                list.remove(ew);
-                ew.remove();
-            }
-        }
-        adapter.update();
-    }
-
-    private void addNewExtractionWord() {
-        EditTextDialogFragment dialogFragment = new EditTextDialogFragment() {
-            @Override
-            public void onTextInput(String text) {
-                if (TextUtils.isEmpty(text.trim())) {
-                    return;
-                }
-                ExtractionWord extractionWord = ExtractionWord.add(text);
-                list.add(extractionWord);
-                adapter.update();
-            }
-        };
-        dialogFragment.setParams(getString(R.string.dialog_title_add), "");
-        dialogFragment.show(getFragmentManager(), "EDIT_TEXT");
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.kt
new file mode 100644
index 00000000..c621b6f7
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/EditExtractionActivity.kt
@@ -0,0 +1,153 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.activity
+
+import android.app.Activity
+import android.os.Bundle
+import android.support.v4.app.NavUtils
+import android.text.TextUtils
+import android.util.SparseBooleanArray
+import android.view.*
+import android.widget.AbsListView
+import android.widget.ListView
+import android.widget.TextView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.data.ExtractionWord
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+import net.lacolaco.smileessence.view.dialog.EditTextDialogFragment
+
+import java.util.ArrayList
+
+class EditExtractionActivity : Activity(), AbsListView.MultiChoiceModeListener {
+    private lateinit var list: MutableList<ExtractionWord>
+    private lateinit var adapter: CustomListAdapter<ExtractionWord>
+
+    private val listView: ListView
+        get() = findViewById(R.id.listview_edit_list) as ListView
+
+    override fun onCreateActionMode(mode: ActionMode, menu: Menu): Boolean {
+        menu.clear()
+        val inflater = mode.menuInflater
+        inflater.inflate(R.menu.edit_list, menu)
+        return true
+    }
+
+    override fun onPrepareActionMode(mode: ActionMode, menu: Menu): Boolean {
+        return false
+    }
+
+    override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.menu_edit_list_delete -> {
+                deleteSelectedItems()
+            }
+        }
+        mode.finish()
+        return true
+    }
+
+    override fun onDestroyActionMode(mode: ActionMode) {}
+
+    override fun onItemCheckedStateChanged(mode: ActionMode, position: Int, id: Long, checked: Boolean) {}
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        Logger.debug("onCreate")
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.layout_edit_list)
+
+        list = ArrayList()
+        adapter = object : CustomListAdapter<ExtractionWord>() {
+            override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+                var convertView = convertView
+                if (convertView == null) {
+                    convertView = this@EditExtractionActivity.layoutInflater.inflate(R.layout.list_item_simple_text, null)
+                }
+                val textView = convertView!!.findViewById(R.id.list_item_textview) as TextView
+                textView.text = getItem(position).patternString
+                return convertView
+            }
+
+            override val list: List<ExtractionWord>
+                get() = this@EditExtractionActivity.list
+        }
+        list.addAll(ExtractionWord.cached())
+        adapter.update()
+        listView.adapter = adapter
+        listView.choiceMode = ListView.CHOICE_MODE_MULTIPLE_MODAL
+        listView.setMultiChoiceModeListener(this)
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        val add = menu.add(Menu.NONE, R.id.menu_edit_list_add, Menu.NONE, "")
+        add.setIcon(android.R.drawable.ic_menu_add)
+        add.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM)
+        return true
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.menu_edit_list_add -> {
+                addNewExtractionWord()
+            }
+            android.R.id.home -> {
+                NavUtils.navigateUpFromSameTask(this)
+                return true
+            }
+        }
+        return true
+    }
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    fun deleteSelectedItems() {
+        val checkedItems = listView.checkedItemPositions
+        for (i in adapter.count - 1 downTo -1 + 1) {
+            if (checkedItems.get(i)) {
+                val ew = adapter.getItem(i)
+                list.remove(ew)
+                ew.remove()
+            }
+        }
+        adapter.update()
+    }
+
+    private fun addNewExtractionWord() {
+        val dialogFragment = object : EditTextDialogFragment() {
+            override fun onTextInput(text: String) {
+                if (TextUtils.isEmpty(text.trim { it <= ' ' })) {
+                    return
+                }
+                val extractionWord = ExtractionWord.add(text)
+                list.add(extractionWord)
+                adapter.update()
+            }
+        }
+        dialogFragment.setParams(getString(R.string.dialog_title_add), "")
+        dialogFragment.show(fragmentManager, "EDIT_TEXT")
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.java
deleted file mode 100644
index 23957c57..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.Activity;
-import android.os.Bundle;
-import android.support.v4.app.NavUtils;
-import android.view.MenuItem;
-import android.widget.LinearLayout;
-import android.widget.TextView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class LicenseActivity extends Activity {
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    private List<String> getFileNames() {
-        List<String> apacheFiles = new ArrayList<>();
-        apacheFiles.add(getString(R.string.library_name_twitter4j));
-        apacheFiles.add(getString(R.string.library_name_crouton));
-        apacheFiles.add(getString(R.string.library_name_pull_to_refresh));
-        apacheFiles.add(getString(R.string.library_name_volley));
-        apacheFiles.add(getString(R.string.library_name_twitter_text));
-        return apacheFiles;
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.layout_license);
-
-        setFiles();
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home: {
-                NavUtils.navigateUpFromSameTask(this);
-                return true;
-            }
-        }
-        return true;
-    }
-
-    private void setFiles() {
-        LinearLayout files = (LinearLayout) findViewById(R.id.linear_license_files);
-        List<String> apacheFiles = getFileNames();
-        for (String apacheFile : apacheFiles) {
-            TextView name = new TextView(this);
-            name.setText(String.format("- %s", apacheFile));
-            files.addView(name);
-        }
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.kt
new file mode 100644
index 00000000..58bcc08c
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/LicenseActivity.kt
@@ -0,0 +1,81 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.activity
+
+import android.app.Activity
+import android.os.Bundle
+import android.support.v4.app.NavUtils
+import android.view.MenuItem
+import android.widget.LinearLayout
+import android.widget.TextView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+
+import java.util.ArrayList
+
+class LicenseActivity : Activity() {
+
+    // --------------------- GETTER / SETTER METHODS ---------------------
+
+    private val fileNames: List<String>
+        get() {
+            val apacheFiles = ArrayList<String>()
+            apacheFiles.add(getString(R.string.library_name_twitter4j))
+            apacheFiles.add(getString(R.string.library_name_crouton))
+            apacheFiles.add(getString(R.string.library_name_pull_to_refresh))
+            apacheFiles.add(getString(R.string.library_name_volley))
+            apacheFiles.add(getString(R.string.library_name_twitter_text))
+            return apacheFiles
+        }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.layout_license)
+
+        setFiles()
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            android.R.id.home -> {
+                NavUtils.navigateUpFromSameTask(this)
+                return true
+            }
+        }
+        return true
+    }
+
+    private fun setFiles() {
+        val files = findViewById(R.id.linear_license_files) as LinearLayout
+        val apacheFiles = fileNames
+        for (apacheFile in apacheFiles) {
+            val name = TextView(this)
+            name.text = String.format("- %s", apacheFile)
+            files.addView(name)
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.java
deleted file mode 100644
index 4997f3f1..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.java
+++ /dev/null
@@ -1,347 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.ActionBar;
-import android.app.Activity;
-import android.app.ActivityManager;
-import android.content.Intent;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.Bundle;
-import android.provider.MediaStore;
-import android.support.v4.view.ViewPager;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.WindowManager;
-import android.widget.ImageView;
-import de.keyboardsurfer.android.widget.crouton.Crouton;
-import net.lacolaco.smileessence.*;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.ExtractionWord;
-import net.lacolaco.smileessence.entity.RBinding;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.twitter.task.Users;
-import net.lacolaco.smileessence.util.BitmapOptimizer;
-import net.lacolaco.smileessence.util.BitmapURLTask;
-import net.lacolaco.smileessence.util.IntentUtils;
-import net.lacolaco.smileessence.util.UIObserverBundle;
-import net.lacolaco.smileessence.view.adapter.PageListAdapter;
-import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment;
-import net.lacolaco.smileessence.view.page.*;
-
-import java.lang.reflect.Field;
-
-public class MainActivity extends Activity implements ViewPager.OnPageChangeListener {
-    public static final int REQUEST_GET_PICTURE_FROM_GALLERY = 11;
-    private final UIObserverBundle currentUserBundle = new UIObserverBundle();
-    private World world;
-    private ViewPager viewPager;
-    private ImageView currentAccountIconImageView;
-    private PageListAdapter pagerAdapter;
-
-    public World getWorld() {
-        return world;
-    }
-
-    private void setSelectedPageIndex(int position) {
-        setSelectedPageIndex(position, true);
-    }
-
-    private void setSelectedPageIndex(int position, boolean smooth) {
-        viewPager.setCurrentItem(position, smooth);
-    }
-
-    public void openHomePage() {
-        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment.class));
-    }
-
-    public void openPostPage() {
-        setSelectedPageIndex(pagerAdapter.getIndex(PostFragment.class));
-    }
-
-    public void openPostPageWithImage(Uri uri) {
-        try {
-            Cursor c = getContentResolver().query(uri, null, null, null, null);
-            assert c != null;
-            c.moveToFirst();
-            String path = c.getString(c.getColumnIndex(MediaStore.MediaColumns.DATA));
-            String rotatedPath = path; // BitmapOptimizer.rotateImageByExif(this, path);
-            world.getPostState().beginTransaction()
-                    .setMediaFilePath(rotatedPath)
-                    .commitWithOpen(this);
-            world.notify(R.string.notice_select_image_succeeded);
-            c.close();
-        } catch (Exception e) {
-            e.printStackTrace();
-            world.notifyError(R.string.notice_select_image_failed);
-        }
-    }
-
-    public void openSearchPage(String query) {
-        SearchFragment fragment = (SearchFragment) pagerAdapter.getCachedFragment(pagerAdapter.getIndex(SearchFragment.class));
-        if (fragment != null) {
-            fragment.startSearch(query);
-            setSelectedPageIndex(pagerAdapter.getIndex(SearchFragment.class));
-        }
-    }
-
-    public void openUserListPage(String listFullName) {
-        UserListFragment fragment = (UserListFragment) pagerAdapter.getCachedFragment(pagerAdapter.getIndex(UserListFragment.class));
-        if (fragment != null) {
-            fragment.startUserList(listFullName);
-            setSelectedPageIndex(pagerAdapter.getIndex(UserListFragment.class));
-        }
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onBackPressed() {
-        this.finish();
-    }
-
-    @Override
-    public void finish() {
-        if (viewPager == null) {
-            super.finish();
-            return;
-        }
-        int homeIndex = pagerAdapter.getIndex(HomeFragment.class);
-        if (viewPager.getCurrentItem() != homeIndex) {
-            viewPager.setCurrentItem(homeIndex, true);
-        } else {
-            ConfirmDialogFragment.show(this, getString(R.string.dialog_confirm_finish_app), super::finish);
-        }
-    }
-
-    @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
-        switch (requestCode) {
-            case REQUEST_GET_PICTURE_FROM_GALLERY:
-                getImageUri(requestCode, resultCode, data);
-                break;
-        }
-    }
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        Logger.debug("onCreate");
-        super.onCreate(savedInstanceState);
-
-        Uri uri = getIntent().getData();
-        if (uri == null) {
-            throw new IllegalStateException("[BUG] data not set");
-        }
-        String userIdValue = uri.getQueryParameter("user_id");
-        if (userIdValue == null)
-            throw new IllegalStateException("[BUG] user_id not set");
-        long userId = Long.parseLong(userIdValue);
-        world = Application.getWorld(userId);
-        world.setMainActivity(this);
-
-        // XXX
-        Account account = world.getAccount();
-
-        setTheme(account.themeIndex == 0 ? R.style.theme_dark : R.style.theme_light);
-        setContentView(R.layout.layout_main);
-
-        viewPager = (ViewPager) findViewById(R.id.viewPager);
-        pagerAdapter = new PageListAdapter(this);
-        viewPager.addOnPageChangeListener(this);
-        getActionBar().setDisplayHomeAsUpEnabled(true);
-        currentAccountIconImageView = (ImageView) findViewById(android.R.id.home);
-        currentAccountIconImageView.setScaleType(ImageView.ScaleType.FIT_XY);
-
-        // TODO: tab order?
-        Bundle args = new Bundle();
-        args.putLong(PageFragment.KEY_USER_ID, account.getUserId());
-        pagerAdapter.addPage(PostFragment.class, getString(R.string.page_name_post), args, false);
-        pagerAdapter.addPage(HomeFragment.class, getString(R.string.page_name_home), args, false);
-        pagerAdapter.addPage(MentionsFragment.class, getString(R.string.page_name_mentions), args, false);
-        pagerAdapter.addPage(HistoryFragment.class, getString(R.string.page_name_history), args, false);
-        pagerAdapter.addPage(MessagesFragment.class, getString(R.string.page_name_messages), args, false);
-        pagerAdapter.addPage(SearchFragment.class, getString(R.string.page_name_search), args, false);
-        pagerAdapter.addPage(UserListFragment.class, getString(R.string.page_name_list), args, false);
-        pagerAdapter.notifyDataSetChanged();
-        viewPager.setOffscreenPageLimit(pagerAdapter.getCount());
-        viewPager.setAdapter(pagerAdapter);
-        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment.class), false);
-
-        ExtractionWord.load();
-
-        // update cache
-        world.refreshListSubscriptions();
-        world.refreshUserMuteList();
-        world.refreshSavedSearches();
-        new Users.GetTask(account, account.getUserId()).execute();
-
-        User user = account.getUser();
-
-        // Set application title
-        setTitle();
-
-        // update actionbar
-        Runnable update = () -> {
-            setTitle();
-            updateActionBarTitle();
-            String newUrl = user.getProfileImageUrlOriginal();
-            if (newUrl != null) {
-                new BitmapURLTask(newUrl, currentAccountIconImageView).execute();
-            }
-        };
-        update.run(); //first run
-
-        currentUserBundle.detachAll();
-        currentUserBundle.attach(user, changes -> {
-            if (changes.contains(RBinding.BASIC)) update.run();
-        });
-
-        // refresh all pages
-        for (int i = 0; i < pagerAdapter.getCount(); ++i) {
-            PageFragment pf = pagerAdapter.getCachedFragment(i);
-            if (pf != null && pf.isAdded()) {
-                Logger.debug(String.format("PageFragment %s is already attached; refreshing", pf.getClass().getName()));
-                pf.refresh();
-            }
-        }
-
-        // start user stream
-        world.setupStreaming();
-    }
-
-    private void setTitle() {
-        String label = getString(R.string.app_name) + " - @" + world.getAccount().getUser().getScreenName();
-        ActivityManager.TaskDescription desc = new ActivityManager.TaskDescription(label);
-        setTaskDescription(desc);
-    }
-
-    @Override
-    protected void onDestroy() {
-        super.onDestroy();
-        currentUserBundle.detachAll();
-        Crouton.cancelAllCroutons();
-        // Workaround for LeakCanary
-        fixCroutonLeak();
-        Logger.debug("onDestroy");
-    }
-
-    private void fixCroutonLeak() {
-        try {
-            Class klass = Class.forName("de.keyboardsurfer.android.widget.crouton.DefaultAnimationsBuilder");
-            Field slideInDownAnimation = klass.getDeclaredField("slideInDownAnimation");
-            slideInDownAnimation.setAccessible(true);
-            slideInDownAnimation.set(null, null);
-            Field slideOutUpAnimation = klass.getDeclaredField("slideOutUpAnimation");
-            slideOutUpAnimation.setAccessible(true);
-            slideOutUpAnimation.set(null, null);
-        } catch (Exception e) {
-            Logger.error("crouton fix error: " + e);
-        }
-    }
-
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.main, menu);
-        return true;
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home: {
-                Intent intent = new Intent(this, ManageAccountsActivity.class);
-                intent.putExtra(ManageAccountsActivity.INTENT_KEY_NOINIT, true);
-                startActivity(intent);
-                return true;
-            }
-            case R.id.actionbar_setting:
-                startActivity(new Intent(this, SettingActivity.class));
-                return true;
-            case R.id.actionbar_edit_extraction:
-                startActivity(new Intent(this, EditExtractionActivity.class));
-                return true;
-            case R.id.actionbar_aclog:
-                IntentUtils.openUri(this, world.getAccount().getUser().getAclogTimelineURL());
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
-
-    @Override
-    protected void onPause() {
-        Logger.debug("onPause");
-        super.onPause();
-        world.setMainActivityActive(false);
-    }
-
-    @Override
-    protected void onResume() {
-        Logger.debug("onResume");
-        super.onResume();
-        world.setMainActivityActive(true);
-    }
-
-    // --------------------- Interface OnPageChangeListener ---------------------
-
-    @Override
-    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
-    }
-
-    @Override
-    public void onPageSelected(int position) {
-        Logger.debug("Page selected: " + position);
-        updateActionBarTitle();
-    }
-
-    @Override
-    public void onPageScrollStateChanged(int state) {
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    private void getImageUri(int requestCode, int resultCode, Intent data) {
-        if (resultCode != RESULT_OK) {
-            Logger.error(requestCode);
-            world.notifyError(R.string.notice_select_image_failed);
-            finish();
-            return;
-        }
-        openPostPageWithImage(data.getData());
-    }
-
-    private void updateActionBarTitle() {
-        ActionBar actionBar = getActionBar();
-        Account currentAccount = world.getAccount();
-        if (actionBar != null) {
-            String screenName = currentAccount.getUser().getScreenName();
-            String pageTitle = pagerAdapter.getName(viewPager.getCurrentItem());
-            setTitle(String.format("%s / %s", screenName, pageTitle));
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt
new file mode 100644
index 00000000..8b8da33f
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt
@@ -0,0 +1,311 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.activity
+
+import android.app.Activity
+import android.app.ActivityManager
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.provider.MediaStore
+import android.support.v4.view.ViewPager
+import android.view.Menu
+import android.view.MenuItem
+import android.widget.ImageView
+import de.keyboardsurfer.android.widget.crouton.Crouton
+import net.lacolaco.smileessence.*
+import net.lacolaco.smileessence.data.ExtractionWord
+import net.lacolaco.smileessence.entity.RBinding
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.twitter.task.Users
+import net.lacolaco.smileessence.util.BitmapURLTask
+import net.lacolaco.smileessence.util.IntentUtils
+import net.lacolaco.smileessence.util.UIObserverBundle
+import net.lacolaco.smileessence.view.adapter.PageListAdapter
+import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment
+import net.lacolaco.smileessence.view.page.*
+
+class MainActivity : Activity(), ViewPager.OnPageChangeListener {
+    private val currentUserBundle = UIObserverBundle()
+    val world: World by lazy {
+        val uri = intent.data ?: throw IllegalStateException("[BUG] data not set")
+        val userIdValue = uri.getQueryParameter("user_id") ?: throw IllegalStateException("[BUG] user_id not set")
+        val userId = java.lang.Long.parseLong(userIdValue)
+        Application.getWorld(userId)
+    }
+    private lateinit var viewPager: ViewPager
+    private lateinit var pagerAdapter: PageListAdapter
+    private lateinit var currentAccountIconImageView: ImageView
+
+    private fun setSelectedPageIndex(position: Int, smooth: Boolean = true) {
+        viewPager.setCurrentItem(position, smooth)
+    }
+
+    fun openHomePage() {
+        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment::class.java))
+    }
+
+    fun openPostPage() {
+        setSelectedPageIndex(pagerAdapter.getIndex(PostFragment::class.java))
+    }
+
+    fun openPostPageWithImage(uri: Uri) {
+        try {
+            val c = contentResolver.query(uri, null, null, null, null)
+            assert(c != null)
+            c!!.moveToFirst()
+            val path = c.getString(c.getColumnIndex(MediaStore.MediaColumns.DATA))
+            world.postState.beginTransaction()
+                    .setMediaFilePath(path)
+                    .commitWithOpen(this)
+            world.notify(R.string.notice_select_image_succeeded)
+            c.close()
+        } catch (e: Exception) {
+            e.printStackTrace()
+            world.notifyError(R.string.notice_select_image_failed)
+        }
+
+    }
+
+    fun openSearchPage(query: String) {
+        val fragment = pagerAdapter.getCachedFragment(pagerAdapter.getIndex(SearchFragment::class.java)) as SearchFragment?
+        if (fragment != null) {
+            fragment.startSearch(query)
+            setSelectedPageIndex(pagerAdapter.getIndex(SearchFragment::class.java))
+        }
+    }
+
+    fun openUserListPage(listFullName: String) {
+        val fragment = pagerAdapter.getCachedFragment(pagerAdapter.getIndex(UserListFragment::class.java)) as UserListFragment?
+        if (fragment != null) {
+            fragment.startUserList(listFullName)
+            setSelectedPageIndex(pagerAdapter.getIndex(UserListFragment::class.java))
+        }
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onBackPressed() {
+        this.finish()
+    }
+
+    override fun finish() {
+        val homeIndex = pagerAdapter.getIndex(HomeFragment::class.java)
+        if (viewPager.currentItem != homeIndex) {
+            viewPager.setCurrentItem(homeIndex, true)
+        } else {
+            ConfirmDialogFragment.show(this, getString(R.string.dialog_confirm_finish_app)) { super.finish() }
+        }
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        when (requestCode) {
+            REQUEST_GET_PICTURE_FROM_GALLERY -> getImageUri(requestCode, resultCode, data)
+        }
+    }
+
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        Logger.debug("onCreate")
+        super.onCreate(savedInstanceState)
+
+        world.setMainActivity(this)
+
+        // XXX
+        val account = world.account
+
+        setTheme(if (account.themeIndex == 0) R.style.theme_dark else R.style.theme_light)
+        setContentView(R.layout.layout_main)
+
+        viewPager = findViewById(R.id.viewPager) as ViewPager
+        pagerAdapter = PageListAdapter(this)
+        viewPager.addOnPageChangeListener(this)
+        actionBar.setDisplayHomeAsUpEnabled(true)
+        currentAccountIconImageView = findViewById(android.R.id.home) as ImageView
+        currentAccountIconImageView.scaleType = ImageView.ScaleType.FIT_XY
+
+        // TODO: tab order?
+        val args = Bundle()
+        args.putLong(PageFragment.KEY_USER_ID, account.userId)
+        pagerAdapter.addPage(PostFragment::class.java, getString(R.string.page_name_post), args, false)
+        pagerAdapter.addPage(HomeFragment::class.java, getString(R.string.page_name_home), args, false)
+        pagerAdapter.addPage(MentionsFragment::class.java, getString(R.string.page_name_mentions), args, false)
+        pagerAdapter.addPage(HistoryFragment::class.java, getString(R.string.page_name_history), args, false)
+        pagerAdapter.addPage(MessagesFragment::class.java, getString(R.string.page_name_messages), args, false)
+        pagerAdapter.addPage(SearchFragment::class.java, getString(R.string.page_name_search), args, false)
+        pagerAdapter.addPage(UserListFragment::class.java, getString(R.string.page_name_list), args, false)
+        pagerAdapter.notifyDataSetChanged()
+        viewPager.offscreenPageLimit = pagerAdapter.count
+        viewPager.adapter = pagerAdapter
+        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment::class.java), false)
+
+        ExtractionWord.load()
+
+        // update cache
+        world.refreshListSubscriptions()
+        world.refreshUserMuteList()
+        world.refreshSavedSearches()
+        Users.GetTask(account, account.userId).execute()
+
+        val user = account.user
+
+        // Set application title
+        setTitle()
+
+        // update actionbar
+        val update = {
+            setTitle()
+            updateActionBarTitle()
+            val newUrl = user.profileImageUrl
+            if (newUrl != null) {
+                BitmapURLTask(newUrl, currentAccountIconImageView).execute()
+            }
+        }
+        update() //first run
+
+        currentUserBundle.detachAll()
+        currentUserBundle.attach(user) { changes -> if (changes.contains(RBinding.BASIC)) update() }
+
+        // refresh all pages
+        for (i in 0..pagerAdapter.count - 1) {
+            val pf = pagerAdapter.getCachedFragment(i)
+            if (pf != null && pf.isAdded) {
+                Logger.debug(String.format("PageFragment %s is already attached; refreshing", pf.javaClass.name))
+                pf.refresh()
+            }
+        }
+
+        // start user stream
+        world.setupStreaming()
+    }
+
+    private fun setTitle() {
+        val label = getString(R.string.app_name) + " - @" + world.account.user.screenName
+        val desc = ActivityManager.TaskDescription(label)
+        setTaskDescription(desc)
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        currentUserBundle.detachAll()
+        Crouton.cancelAllCroutons()
+        // Workaround for LeakCanary
+        fixCroutonLeak()
+        Logger.debug("onDestroy")
+    }
+
+    private fun fixCroutonLeak() {
+        try {
+            val klass = Class.forName("de.keyboardsurfer.android.widget.crouton.DefaultAnimationsBuilder")
+            val slideInDownAnimation = klass.getDeclaredField("slideInDownAnimation")
+            slideInDownAnimation.isAccessible = true
+            slideInDownAnimation.set(null, null)
+            val slideOutUpAnimation = klass.getDeclaredField("slideOutUpAnimation")
+            slideOutUpAnimation.isAccessible = true
+            slideOutUpAnimation.set(null, null)
+        } catch (e: Exception) {
+            Logger.error("crouton fix error: " + e)
+        }
+
+    }
+
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.main, menu)
+        return true
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            android.R.id.home -> {
+                val intent = Intent(this, ManageAccountsActivity::class.java)
+                intent.putExtra(ManageAccountsActivity.INTENT_KEY_NOINIT, true)
+                startActivity(intent)
+                return true
+            }
+            R.id.actionbar_setting -> {
+                startActivity(Intent(this, SettingActivity::class.java))
+                return true
+            }
+            R.id.actionbar_edit_extraction -> {
+                startActivity(Intent(this, EditExtractionActivity::class.java))
+                return true
+            }
+            R.id.actionbar_aclog -> {
+                IntentUtils.openUri(this, world.account.user.aclogTimelineURL)
+                return true
+            }
+            else -> return super.onOptionsItemSelected(item)
+        }
+    }
+
+    override fun onPause() {
+        Logger.debug("onPause")
+        super.onPause()
+        world.setMainActivityActive(false)
+    }
+
+    override fun onResume() {
+        Logger.debug("onResume")
+        super.onResume()
+        world.setMainActivityActive(true)
+    }
+
+    // --------------------- Interface OnPageChangeListener ---------------------
+
+    override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {}
+
+    override fun onPageSelected(position: Int) {
+        Logger.debug("Page selected: " + position)
+        updateActionBarTitle()
+    }
+
+    override fun onPageScrollStateChanged(state: Int) {}
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    private fun getImageUri(requestCode: Int, resultCode: Int, data: Intent?) {
+        if (resultCode != Activity.RESULT_OK) {
+            Logger.error(requestCode)
+            world.notifyError(R.string.notice_select_image_failed)
+            finish()
+            return
+        }
+        openPostPageWithImage(data!!.data)
+    }
+
+    private fun updateActionBarTitle() {
+        val actionBar = actionBar
+        val currentAccount = world.account
+        if (actionBar != null) {
+            val screenName = currentAccount.user.screenName
+            val pageTitle = pagerAdapter.getName(viewPager.currentItem)
+            title = String.format("%s / %s", screenName, pageTitle)
+        }
+    }
+
+    companion object {
+        val REQUEST_GET_PICTURE_FROM_GALLERY = 11
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.java
deleted file mode 100644
index af891fec..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.java
+++ /dev/null
@@ -1,257 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.Activity;
-import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.net.Uri;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.*;
-import com.android.volley.toolbox.NetworkImageView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.ImageCache;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.twitter.OAuthSession;
-import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class ManageAccountsActivity extends Activity implements AdapterView.OnItemClickListener, AdapterView.OnItemLongClickListener {
-    public static final String INTENT_KEY_NOINIT = "noInit";
-    private static final int REQUEST_OAUTH = 10;
-    private static final int REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION = 11;
-    private EditAccountsAdapter adapter;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        // Check if it is initiated from launcher
-        if (!getIntent().getBooleanExtra(INTENT_KEY_NOINIT, false)) {
-            int wextPermission = ContextCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE);
-            if (wextPermission != PackageManager.PERMISSION_GRANTED) {
-                ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION);
-            }
-
-            // Skip this activity if app is already started
-            World currentWorld = Application.getCurrentWorld();
-            if (currentWorld != null) {
-                goToWorld(currentWorld);
-                return;
-            }
-        }
-
-        setContentView(R.layout.layout_edit_list);
-        adapter = new EditAccountsAdapter();
-        ListView listView = (ListView) findViewById(R.id.listview_edit_list);
-        listView.setAdapter(adapter);
-        listView.setOnItemClickListener(this);
-        listView.setOnItemLongClickListener(this);
-    }
-
-    @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
-        switch (requestCode) {
-            case REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION: {
-                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                    // OK
-                    World currentWorld = Application.getCurrentWorld();
-                    if (currentWorld != null) {
-                        goToWorld(currentWorld);
-                    }
-                } else {
-                    Application.toast(R.string.notice_error_storage_permission);
-                    // TODO: Kill Process?
-                    finish();
-                }
-                break;
-            }
-        }
-    }
-
-    private void goToWorld(World world) {
-        // Continue the existing MainActivity
-        Intent intent = new Intent(this, MainActivity.class);
-        intent.setData(Uri.parse("smileessence://mainactivity/?user_id=" + world.getAccount().getUserId()));
-        finish();
-        startActivity(intent);
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        MenuItem add = menu.add(Menu.NONE, R.id.menu_edit_list_add, Menu.NONE, "");
-        add.setIcon(android.R.drawable.ic_menu_add);
-        add.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
-        return true;
-    }
-
-    @Override
-    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
-        Account account = adapter.getItem(i);
-        goToWorld(Application.getWorld(account.getUserId()));
-    }
-
-    @Override
-    public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
-        if (adapter.getCount() > 1) {
-            // remove account from application
-            Account account = adapter.getItem(i);
-            ConfirmDialogFragment.show(this, getString(R.string.dialog_confirm_clear_account, account.getUser().getScreenName()), () -> {
-                adapter.removeAt(i);
-                Account.unregister(account.getUserId());
-            }, false);
-            return true;
-        } else {
-            Application.toast(R.string.notice_cant_remove_last_account);
-            return false;
-        }
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.menu_edit_list_add: {
-                startActivityForResult(new Intent(this, OAuthActivity.class), REQUEST_OAUTH);
-                break;
-            }
-            case android.R.id.home: {
-                safeFinish();
-            }
-        }
-        return true;
-    }
-
-    @Override
-    public void onBackPressed() {
-        safeFinish();
-    }
-
-    private void safeFinish() {
-        World currentWorld = Application.getCurrentWorld();
-
-        if (currentWorld != null) {
-            goToWorld(currentWorld);
-        } else {
-            setResult(RESULT_CANCELED);
-            finish();
-        }
-    }
-
-    @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
-        switch (requestCode) {
-            case REQUEST_OAUTH: {
-                receiveOAuth(requestCode, resultCode, data);
-                break;
-            }
-            default: {
-                Logger.error("[BUG] unexpected activity result: reqCode=" + requestCode + ", resCode=" + resultCode);
-                break;
-            }
-        }
-    }
-
-    private void receiveOAuth(int requestCode, int resultCode, Intent data) {
-        if (resultCode == RESULT_OK) {
-            Account account = Account.register(data.getStringExtra(OAuthSession.KEY_TOKEN),
-                    data.getStringExtra(OAuthSession.KEY_TOKEN_SECRET),
-                    data.getLongExtra(OAuthSession.KEY_USER_ID, -1L),
-                    data.getStringExtra(OAuthSession.KEY_SCREEN_NAME));
-            adapter.add(account);
-        } else {
-            Logger.error(requestCode);
-            Application.toast(R.string.notice_error_authenticate);
-        }
-    }
-
-    private class EditAccountsAdapter extends BaseAdapter {
-        private final List<Account> accounts;
-
-        public EditAccountsAdapter() {
-            accounts = new ArrayList<>(Account.all());
-        }
-
-        @Override
-        public int getCount() {
-            return accounts.size();
-        }
-
-        @Override
-        public Account getItem(int position) {
-            return accounts.get(position);
-        }
-
-        @Override
-        public long getItemId(int position) {
-            return accounts.get(position).getUserId();
-        }
-
-        @Override
-        public View getView(int position, View convertView, ViewGroup parent) {
-            if (convertView == null) {
-                convertView = getLayoutInflater().inflate(R.layout.list_item_account, null);
-            }
-            Account account = getItem(position);
-            NetworkImageView iconView = (NetworkImageView) convertView.findViewById(R.id.account_icon);
-            iconView.setImageUrl(account.getUser().getProfileImageUrlOriginal(), ImageCache.getImageLoader());
-
-            TextView textView = (TextView) convertView.findViewById(R.id.account_text_view);
-            String text = "@" + account.getUser().getScreenName();
-            textView.setText(text);
-
-            return convertView;
-        }
-
-        public int add(Account account) {
-            if (!accounts.contains(account)) {
-                accounts.add(account);
-                notifyDataSetChanged();
-                return accounts.size() - 1;
-            } else {
-                return accounts.indexOf(account);
-            }
-        }
-
-        public Account removeAt(int position) {
-            Account account = accounts.remove(position);
-            if (account != null) {
-                notifyDataSetChanged();
-            }
-            return account;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.kt
new file mode 100644
index 00000000..2ef184fc
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/ManageAccountsActivity.kt
@@ -0,0 +1,241 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.activity
+
+import android.app.Activity
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.net.Uri
+import android.os.Bundle
+import android.support.v4.app.ActivityCompat
+import android.support.v4.content.ContextCompat
+import android.view.Menu
+import android.view.MenuItem
+import android.view.View
+import android.view.ViewGroup
+import android.widget.*
+import com.android.volley.toolbox.NetworkImageView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.data.ImageCache
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.twitter.OAuthSession
+import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment
+
+import java.util.ArrayList
+
+class ManageAccountsActivity : Activity(), AdapterView.OnItemClickListener, AdapterView.OnItemLongClickListener {
+    private var adapter: EditAccountsAdapter? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        // Check if it is initiated from launcher
+        if (!intent.getBooleanExtra(INTENT_KEY_NOINIT, false)) {
+            val wextPermission = ContextCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
+            if (wextPermission != PackageManager.PERMISSION_GRANTED) {
+                ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.WRITE_EXTERNAL_STORAGE), REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION)
+            }
+
+            // Skip this activity if app is already started
+            val currentWorld = Application.currentWorld
+            if (currentWorld != null) {
+                goToWorld(currentWorld)
+                return
+            }
+        }
+
+        setContentView(R.layout.layout_edit_list)
+        adapter = EditAccountsAdapter()
+        val listView = findViewById(R.id.listview_edit_list) as ListView
+        listView.adapter = adapter
+        listView.onItemClickListener = this
+        listView.onItemLongClickListener = this
+    }
+
+    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
+        when (requestCode) {
+            REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION -> {
+                if (grantResults.size > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                    // OK
+                    val currentWorld = Application.currentWorld
+                    if (currentWorld != null) {
+                        goToWorld(currentWorld)
+                    }
+                } else {
+                    Application.toast(R.string.notice_error_storage_permission)
+                    // TODO: Kill Process?
+                    finish()
+                }
+            }
+        }
+    }
+
+    private fun goToWorld(world: World) {
+        // Continue the existing MainActivity
+        val intent = Intent(this, MainActivity::class.java)
+        intent.data = Uri.parse("smileessence://mainactivity/?user_id=" + world.account.userId)
+        finish()
+        startActivity(intent)
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        val add = menu.add(Menu.NONE, R.id.menu_edit_list_add, Menu.NONE, "")
+        add.setIcon(android.R.drawable.ic_menu_add)
+        add.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM)
+        return true
+    }
+
+    override fun onItemClick(adapterView: AdapterView<*>, view: View, i: Int, l: Long) {
+        val account = adapter!!.getItem(i)
+        goToWorld(Application.getWorld(account.userId))
+    }
+
+    override fun onItemLongClick(adapterView: AdapterView<*>, view: View, i: Int, l: Long): Boolean {
+        if (adapter!!.count > 1) {
+            // remove account from application
+            val account = adapter!!.getItem(i)
+            ConfirmDialogFragment.show(this, getString(R.string.dialog_confirm_clear_account, account.user.screenName), {
+                adapter!!.removeAt(i)
+                Account.unregister(account.userId)
+            }, false)
+            return true
+        } else {
+            Application.toast(R.string.notice_cant_remove_last_account)
+            return false
+        }
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.menu_edit_list_add -> {
+                startActivityForResult(Intent(this, OAuthActivity::class.java), REQUEST_OAUTH)
+            }
+            android.R.id.home -> {
+                safeFinish()
+            }
+        }
+        return true
+    }
+
+    override fun onBackPressed() {
+        safeFinish()
+    }
+
+    private fun safeFinish() {
+        val currentWorld = Application.currentWorld
+
+        if (currentWorld != null) {
+            goToWorld(currentWorld)
+        } else {
+            setResult(Activity.RESULT_CANCELED)
+            finish()
+        }
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
+        when (requestCode) {
+            REQUEST_OAUTH -> {
+                receiveOAuth(requestCode, resultCode, data)
+            }
+            else -> {
+                Logger.error("[BUG] unexpected activity result: reqCode=$requestCode, resCode=$resultCode")
+            }
+        }
+    }
+
+    private fun receiveOAuth(requestCode: Int, resultCode: Int, data: Intent) {
+        if (resultCode == Activity.RESULT_OK) {
+            val account = Account.register(data.getStringExtra(OAuthSession.KEY_TOKEN),
+                    data.getStringExtra(OAuthSession.KEY_TOKEN_SECRET),
+                    data.getLongExtra(OAuthSession.KEY_USER_ID, -1L),
+                    data.getStringExtra(OAuthSession.KEY_SCREEN_NAME))
+            adapter!!.add(account)
+        } else {
+            Logger.error(requestCode)
+            Application.toast(R.string.notice_error_authenticate)
+        }
+    }
+
+    private inner class EditAccountsAdapter : BaseAdapter() {
+        private val accounts: MutableList<Account>
+
+        init {
+            accounts = ArrayList(Account.all())
+        }
+
+        override fun getCount(): Int {
+            return accounts.size
+        }
+
+        override fun getItem(position: Int): Account {
+            return accounts[position]
+        }
+
+        override fun getItemId(position: Int): Long {
+            return accounts[position].userId
+        }
+
+        override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+            var convertView = convertView
+            if (convertView == null) {
+                convertView = layoutInflater.inflate(R.layout.list_item_account, null)
+            }
+            val account = getItem(position)
+            val iconView = convertView!!.findViewById(R.id.account_icon) as NetworkImageView
+            iconView.setImageUrl(account.user.profileImageUrl, ImageCache.getImageLoader())
+
+            val textView = convertView.findViewById(R.id.account_text_view) as TextView
+            val text = "@" + account.user.screenName
+            textView.text = text
+
+            return convertView
+        }
+
+        fun add(account: Account): Int {
+            if (!accounts.contains(account)) {
+                accounts.add(account)
+                notifyDataSetChanged()
+                return accounts.size - 1
+            } else {
+                return accounts.indexOf(account)
+            }
+        }
+
+        fun removeAt(position: Int): Account? {
+            val account = accounts.removeAt(position)
+            notifyDataSetChanged()
+            return account
+        }
+    }
+
+    companion object {
+        val INTENT_KEY_NOINIT = "noInit"
+        private val REQUEST_OAUTH = 10
+        private val REQUEST_WRITE_EXTERNAL_STORAGE_PERMISSION = 11
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.java
deleted file mode 100644
index e3d15bc2..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.java
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.Activity;
-import android.content.Intent;
-import android.os.Bundle;
-import android.text.Editable;
-import android.text.TextUtils;
-import android.text.TextWatcher;
-import android.view.View;
-import android.widget.Button;
-import android.widget.EditText;
-import android.widget.TextView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.twitter.OAuthSession;
-import twitter4j.auth.AccessToken;
-
-public class OAuthActivity extends Activity implements View.OnClickListener, TextWatcher {
-    private EditText pinEditText;
-    private Button authButton;
-    private OAuthSession oauthSession;
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.layout_oauth);
-
-        TextView linkTextView = (TextView) findViewById(R.id.textView_oauth_link);
-        pinEditText = (EditText) findViewById(R.id.editText_oauth_pin);
-        pinEditText.addTextChangedListener(this);
-        authButton = (Button) findViewById(R.id.button_oauth_auth);
-        authButton.setOnClickListener(this);
-        authButton.setEnabled(false);
-
-        oauthSession = new OAuthSession();
-        String url = oauthSession.getAuthorizationURL();
-        if (!TextUtils.isEmpty(url)) {
-            linkTextView.setText(url);
-        } else {
-            Application.toast(R.string.notice_error_authenticate_request);
-            finish();
-        }
-    }
-
-    @Override
-    public void onClick(View v) {
-        switch (v.getId()) {
-            case R.id.button_oauth_auth: {
-                AccessToken accessToken = oauthSession.getAccessToken(pinEditText.getText().toString());
-                if (accessToken != null) {
-                    Intent intent = new Intent();
-                    intent.putExtra(OAuthSession.KEY_TOKEN, accessToken.getToken());
-                    intent.putExtra(OAuthSession.KEY_TOKEN_SECRET, accessToken.getTokenSecret());
-                    intent.putExtra(OAuthSession.KEY_USER_ID, accessToken.getUserId());
-                    intent.putExtra(OAuthSession.KEY_SCREEN_NAME, accessToken.getScreenName());
-                    setResult(RESULT_OK, intent);
-                    finish();
-                } else {
-                    setResult(RESULT_CANCELED);
-                    finish();
-                }
-            }
-        }
-    }
-
-    @Override
-    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
-    }
-
-    @Override
-    public void onTextChanged(CharSequence s, int start, int before, int count) {
-        authButton.setEnabled(s.length() > 0);
-    }
-
-    @Override
-    public void afterTextChanged(Editable s) {
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.kt
new file mode 100644
index 00000000..c2388bbf
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/OAuthActivity.kt
@@ -0,0 +1,95 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.activity
+
+import android.app.Activity
+import android.content.Intent
+import android.os.Bundle
+import android.text.Editable
+import android.text.TextUtils
+import android.text.TextWatcher
+import android.view.View
+import android.widget.Button
+import android.widget.EditText
+import android.widget.TextView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.twitter.OAuthSession
+import twitter4j.auth.AccessToken
+
+class OAuthActivity : Activity(), View.OnClickListener, TextWatcher {
+    private lateinit var pinEditText: EditText
+    private lateinit var authButton: Button
+    private lateinit var oauthSession: OAuthSession
+
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.layout_oauth)
+
+        val linkTextView = findViewById(R.id.textView_oauth_link) as TextView
+        pinEditText = findViewById(R.id.editText_oauth_pin) as EditText
+        pinEditText.addTextChangedListener(this)
+        authButton = findViewById(R.id.button_oauth_auth) as Button
+        authButton.setOnClickListener(this)
+        authButton.isEnabled = false
+
+        oauthSession = OAuthSession()
+        val url = oauthSession.authorizationURL
+        if (!TextUtils.isEmpty(url)) {
+            linkTextView.text = url
+        } else {
+            Application.toast(R.string.notice_error_authenticate_request)
+            finish()
+        }
+    }
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.button_oauth_auth -> {
+                val accessToken = oauthSession.getAccessToken(pinEditText.text.toString())
+                if (accessToken != null) {
+                    val intent = Intent()
+                    intent.putExtra(OAuthSession.KEY_TOKEN, accessToken.token)
+                    intent.putExtra(OAuthSession.KEY_TOKEN_SECRET, accessToken.tokenSecret)
+                    intent.putExtra(OAuthSession.KEY_USER_ID, accessToken.userId)
+                    intent.putExtra(OAuthSession.KEY_SCREEN_NAME, accessToken.screenName)
+                    setResult(Activity.RESULT_OK, intent)
+                    finish()
+                } else {
+                    setResult(Activity.RESULT_CANCELED)
+                    finish()
+                }
+            }
+        }
+    }
+
+    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
+
+    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
+        authButton.isEnabled = s.length > 0
+    }
+
+    override fun afterTextChanged(s: Editable) {}
+}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/SettingActivity.java b/app/src/main/java/net/lacolaco/smileessence/activity/SettingActivity.java
deleted file mode 100644
index 87f44e16..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/activity/SettingActivity.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.activity;
-
-import android.app.Activity;
-import android.os.Bundle;
-import android.support.v4.app.NavUtils;
-import android.view.MenuItem;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-
-public class SettingActivity extends Activity {
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.layout_setting);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home: {
-                NavUtils.navigateUpFromSameTask(this);
-                return true;
-            }
-        }
-        return true;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/HistoryFragment.java b/app/src/main/java/net/lacolaco/smileessence/activity/SettingActivity.kt
index 5f04114e..07518480 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/HistoryFragment.java
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/SettingActivity.kt
@@ -22,25 +22,28 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.view.page;
+package net.lacolaco.smileessence.activity
 
-import android.os.Bundle;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.view.adapter.EventListAdapter;
+import android.app.Activity
+import android.os.Bundle
+import android.support.v4.app.NavUtils
+import android.view.MenuItem
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
 
-public class HistoryFragment extends CustomListFragment<EventListAdapter> {
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        World world = getWorld();
-        final EventListAdapter adapter = new EventListAdapter(world, getActivity());
-        setAdapter(adapter);
-        world.addEventNotifier(this, () -> adapter.update()); // XXX
+class SettingActivity : Activity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.layout_setting)
     }
 
-    @Override
-    public void refresh() {
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            android.R.id.home -> {
+                NavUtils.navigateUpFromSameTask(this)
+                return true
+            }
+        }
+        return true
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/Command.java b/app/src/main/java/net/lacolaco/smileessence/command/Command.kt
index 0225b886..98183dc7 100644
--- a/app/src/main/java/net/lacolaco/smileessence/command/Command.java
+++ b/app/src/main/java/net/lacolaco/smileessence/command/Command.kt
@@ -22,23 +22,14 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.command;
+package net.lacolaco.smileessence.command
 
-import net.lacolaco.smileessence.activity.MainActivity;
+import net.lacolaco.smileessence.activity.MainActivity
 
-public abstract class Command {
-    private final MainActivity activity;
+abstract class Command(protected val activity: MainActivity) {
 
-    public Command(MainActivity activity) {
-        this.activity = activity;
-    }
+    abstract fun execute(): Boolean
 
-    protected MainActivity getActivity() {
-        return activity;
-    }
-
-    public abstract boolean execute();
-
-    public abstract String getText();
+    abstract val text: String
 
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenURL.java b/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt
index c62e2601..5d8077d5 100644
--- a/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenURL.java
+++ b/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt
@@ -22,36 +22,27 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.command;
+package net.lacolaco.smileessence.command
 
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.util.IntentUtils;
+import net.lacolaco.smileessence.activity.MainActivity
 
-public class CommandOpenURL extends Command {
+class CommandAddHashtag
+// --------------------------- CONSTRUCTORS ---------------------------
 
-    // ------------------------------ FIELDS ------------------------------
+(activity: MainActivity,
+        // ------------------------------ FIELDS ------------------------------
 
-    private final String url;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public CommandOpenURL(MainActivity activity, String url) {
-        super(activity);
-        this.url = url;
-    }
+ private val hashtag: String) : Command(activity) {
 
     // --------------------- GETTER / SETTER METHODS ---------------------
 
-    @Override
-    public String getText() {
-        return url;
-    }
+    override val text: String
+        get() = "#" + hashtag
 
     // -------------------------- OTHER METHODS --------------------------
 
-    @Override
-    public boolean execute() {
-        IntentUtils.openUri(getActivity(), url);
-        return true;
+    override fun execute(): Boolean {
+        activity.world.postState.beginTransaction().appendText(" #" + hashtag).commit()
+        return true
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenURL.kt b/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenURL.kt
new file mode 100644
index 00000000..b9150e12
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenURL.kt
@@ -0,0 +1,46 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.command
+
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.util.IntentUtils
+
+class CommandOpenURL
+// --------------------------- CONSTRUCTORS ---------------------------
+
+(activity: MainActivity,
+        // ------------------------------ FIELDS ------------------------------
+
+        // --------------------- GETTER / SETTER METHODS ---------------------
+
+ override val text: String) : Command(activity) {
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    override fun execute(): Boolean {
+        IntentUtils.openUri(activity, text)
+        return true
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenUserDetail.java b/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenUserDetail.java
deleted file mode 100644
index 600e0bc0..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenUserDetail.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.command;
-
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.twitter.task.Users;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment;
-
-public class CommandOpenUserDetail extends Command {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private final String screenName;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public CommandOpenUserDetail(MainActivity activity, String screenName) {
-        super(activity);
-        this.screenName = screenName;
-    }
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    @Override
-    public String getText() {
-        return String.format("@%s", screenName);
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    @Override
-    public boolean execute() {
-        new Users.GetTask(getActivity().getWorld().getAccount(), screenName)
-                .onDoneUI(user -> {
-                    UserDetailDialogFragment fragment = new UserDetailDialogFragment();
-                    fragment.setUserID(user.getId());
-                    DialogHelper.showDialog(getActivity(), fragment);
-                })
-                .onFail(x -> getActivity().getWorld().notifyError(R.string.notice_error_show_user))
-                .execute();
-
-        return false;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/preference/UserPreferenceHelper.java b/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenUserDetail.kt
index e3eb95ea..89d5d2ef 100644
--- a/app/src/main/java/net/lacolaco/smileessence/preference/UserPreferenceHelper.java
+++ b/app/src/main/java/net/lacolaco/smileessence/command/CommandOpenUserDetail.kt
@@ -22,37 +22,37 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.preference;
+package net.lacolaco.smileessence.command
 
-import android.content.SharedPreferences;
-import android.preference.PreferenceManager;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.twitter.task.Users
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment
 
-public class UserPreferenceHelper extends SharedPreferenceHelper {
-    // --------------------------- CONSTRUCTORS ---------------------------
+class CommandOpenUserDetail
+// --------------------------- CONSTRUCTORS ---------------------------
 
-    private static final UserPreferenceHelper instance = new UserPreferenceHelper();
+(activity: MainActivity,
+        // ------------------------------ FIELDS ------------------------------
 
-    private UserPreferenceHelper() {
-    }
-
-    public static UserPreferenceHelper getInstance() {
-        return instance;
-    }
+ private val screenName: String) : Command(activity) {
 
     // --------------------- GETTER / SETTER METHODS ---------------------
-    @Override
-    protected SharedPreferences getPreferences() {
-        return PreferenceManager.getDefaultSharedPreferences(Application.getInstance());
-    }
 
-    // --------------------- HELPER METHODS ---------------------
-    public int getThemeIndex() {
-        return get(R.string.key_setting_theme, 0);
-    }
+    override val text: String
+        get() = String.format("@%s", screenName)
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    override fun execute(): Boolean {
+        Users.GetTask(activity.world.account, screenName)
+                .onDoneUI { user ->
+                    DialogHelper.showDialog(activity, UserDetailDialogFragment.newInstance(user))
+                }
+                .onFail { x -> activity.world.notifyError(R.string.notice_error_show_user) }
+                .execute()
 
-    public int getTextSize() {
-        return get(R.string.key_setting_text_size, 10);
+        return false
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/compat/Twitter4J.java b/app/src/main/java/net/lacolaco/smileessence/compat/Twitter4J.java
new file mode 100644
index 00000000..1d9ab25e
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/compat/Twitter4J.java
@@ -0,0 +1,11 @@
+package net.lacolaco.smileessence.compat;
+
+import twitter4j.StatusListener;
+import twitter4j.TwitterStream;
+
+public class Twitter4J {
+    // Make it work with Kotlin. Problem exists in v4.0.6
+    public static void twitterStreamAddListener(TwitterStream stream, StatusListener listener) {
+        stream.addListener(listener);
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/Account.java b/app/src/main/java/net/lacolaco/smileessence/data/Account.java
deleted file mode 100644
index 280f9a09..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/Account.java
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.data;
-
-import com.github.gfx.android.orma.annotation.Column;
-import com.github.gfx.android.orma.annotation.PrimaryKey;
-import com.github.gfx.android.orma.annotation.Table;
-import net.lacolaco.smileessence.entity.User;
-import twitter4j.Twitter;
-import twitter4j.TwitterFactory;
-import twitter4j.TwitterStream;
-import twitter4j.TwitterStreamFactory;
-import twitter4j.auth.AccessToken;
-import twitter4j.conf.ConfigurationBuilder;
-
-import java.util.*;
-
-@Table
-public class Account {
-    private static Map<Long, Account> cache;
-    @PrimaryKey
-    public long userId;
-    @Column
-    public String screenName;
-    @Column
-    public String oauthToken;
-    @Column
-    public String oauthTokenSecret;
-    @Column(defaultExpr = "0")
-    public int themeIndex;
-
-    private User user;
-
-    public Account() {
-    }
-
-    public static synchronized Account get(long i) {
-        if (cache == null) {
-            throw new IllegalStateException("[BUG] Load first");
-        }
-        Account a = cache.get(i);
-        if (a == null)
-            throw new IllegalStateException("[BUG] Account with userId == " + i + " not found");
-        return a;
-    }
-
-    public static synchronized List<Account> all() {
-        return new ArrayList<>(cache.values());
-    }
-
-    public static synchronized void load() {
-        cache = new LinkedHashMap<>();
-        for (Account item : relation().selector())
-            cache.put(item.userId, item);
-    }
-
-    private static Account_Relation relation() {
-        OrmaDatabase orma = OrmaHolder.getORMA();
-        return orma.relationOfAccount();
-    }
-
-    public static synchronized Account register(String token, String tokenSecret, long userId, String screenName) {
-        Account account = null;
-        for (Account a : all()) {
-            if (a.getUserId() == userId) {
-                account = a;
-                break;
-            }
-        }
-        if (account == null)
-            account = new Account();
-        account.userId = userId;
-        account.screenName = screenName;
-        account.oauthToken = token;
-        account.oauthTokenSecret = tokenSecret;
-        account.themeIndex = 0;
-
-        relation().upserter().execute(account);
-
-        cache.put(account.userId, account);
-
-        return account;
-    }
-
-    public static synchronized Account unregister(long id) {
-        Account account = cache.remove(id);
-        if (account != null) {
-            relation().deleter().userIdEq(id).execute();
-        }
-        return account;
-    }
-
-    public long getUserId() {
-        return userId;
-    }
-
-    public Twitter getTwitter() {
-        ConfigurationBuilder cb = new ConfigurationBuilder();
-        cb.setTweetModeExtended(true);
-        Twitter twitter = new TwitterFactory(cb.build()).getInstance();
-        twitter.setOAuthAccessToken(new AccessToken(oauthToken, oauthTokenSecret));
-        return twitter;
-    }
-
-    public TwitterStream getTwitterStream() {
-        TwitterStream stream = new TwitterStreamFactory().getInstance();
-        stream.setOAuthAccessToken(new AccessToken(oauthToken, oauthTokenSecret));
-        return stream;
-    }
-
-    public User getUser() {
-        if (user == null) {
-            user = User.fetch(userId);
-            if (user == null) {
-                user = User._makeSkeleton(userId, screenName);
-            }
-            user.addObserver(this, (objs) -> {
-                if (!screenName.equals(user.getScreenName())) {
-                    screenName = user.getScreenName();
-                    relation().upserter().execute(this);
-                }
-            });
-        }
-
-        return user;
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/Account.kt b/app/src/main/java/net/lacolaco/smileessence/data/Account.kt
new file mode 100644
index 00000000..6dc8262c
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/data/Account.kt
@@ -0,0 +1,134 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.data
+
+import com.github.gfx.android.orma.annotation.Column
+import com.github.gfx.android.orma.annotation.PrimaryKey
+import com.github.gfx.android.orma.annotation.Table
+import net.lacolaco.smileessence.data.Account.Companion.cache
+import net.lacolaco.smileessence.entity.User
+import twitter4j.Twitter
+import twitter4j.TwitterFactory
+import twitter4j.TwitterStream
+import twitter4j.TwitterStreamFactory
+import twitter4j.auth.AccessToken
+import twitter4j.conf.ConfigurationBuilder
+
+import java.util.*
+
+@Table
+class Account {
+    @PrimaryKey
+    var userId: Long = 0
+    @Column
+    var screenName: String? = null
+    @Column
+    var oauthToken: String? = null
+    @Column
+    var oauthTokenSecret: String? = null
+    @Column(defaultExpr = "0")
+    var themeIndex: Int = 0
+
+    val user: User by lazy {
+        val _user = User.fetch(userId) ?: User._makeSkeleton(userId, screenName!!)
+        _user.addObserver(this) { objs ->
+            if (screenName!! != _user.screenName) {
+                screenName = _user.screenName
+                relation().upserter().execute(this)
+            }
+        }
+        _user
+    }
+
+    val twitter: Twitter
+    get() {
+        val cb = ConfigurationBuilder()
+        cb.setTweetModeExtended(true)
+        val twitter = TwitterFactory(cb.build()).instance
+        twitter.oAuthAccessToken = AccessToken(oauthToken, oauthTokenSecret)
+        return twitter
+    }
+
+    val twitterStream: TwitterStream
+        get() {
+            val stream = TwitterStreamFactory().instance
+            stream.oAuthAccessToken = AccessToken(oauthToken, oauthTokenSecret)
+            return stream
+        }
+
+
+    companion object {
+        private var cache: MutableMap<Long, Account>? = null
+
+        @Synchronized
+        operator fun get(i: Long): Account {
+            if (cache == null) {
+                throw IllegalStateException("[BUG] Load first")
+            }
+            return cache!![i] ?: throw IllegalStateException("[BUG] Account with userId == $i not found")
+        }
+
+        @Synchronized
+        fun all(): List<Account> {
+            return ArrayList(cache!!.values)
+        }
+
+        @Synchronized
+        fun load() {
+            cache = LinkedHashMap()
+            for (item in relation().selector())
+                cache!!.put(item.userId, item)
+        }
+
+        private fun relation(): Account_Relation {
+            return OrmaHolder.orma.relationOfAccount()
+        }
+
+        @Synchronized
+        fun register(token: String, tokenSecret: String, userId: Long, screenName: String): Account {
+            val account = all().find { a -> a.userId == userId } ?: Account()
+            account.userId = userId
+            account.screenName = screenName
+            account.oauthToken = token
+            account.oauthTokenSecret = tokenSecret
+            account.themeIndex = 0
+
+            relation().upserter().execute(account)
+
+            cache!!.put(account.userId, account)
+
+            return account
+        }
+
+        @Synchronized
+        fun unregister(id: Long): Account? {
+            val account = cache!!.remove(id)
+            if (account != null) {
+                relation().deleter().userIdEq(id).execute()
+            }
+            return account
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.java b/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.java
deleted file mode 100644
index 334ab5e7..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.java
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.data;
-
-import com.github.gfx.android.orma.annotation.PrimaryKey;
-import com.github.gfx.android.orma.annotation.Table;
-
-import java.util.*;
-import java.util.regex.Pattern;
-
-@Table
-public class ExtractionWord {
-    private static Set<ExtractionWord> cache;
-    @PrimaryKey
-    String patternString;
-    private Pattern pattern;
-
-    public ExtractionWord() {
-    }
-
-    private ExtractionWord(String patternString) {
-        this.patternString = patternString;
-    }
-
-    public static synchronized Collection<ExtractionWord> cached() {
-        return cache;
-    }
-
-    public static synchronized void load() {
-        OrmaDatabase orma = OrmaHolder.getORMA();
-        cache = new HashSet<>(orma.selectFromExtractionWord().toList());
-    }
-
-    private static ExtractionWord_Relation relation() {
-        return OrmaHolder.getORMA().relationOfExtractionWord();
-    }
-
-    public static synchronized ExtractionWord add(String patternString) {
-        ExtractionWord extractionWord = new ExtractionWord(patternString);
-        relation().upserter().execute(extractionWord);
-        cache.add(extractionWord);
-        return extractionWord;
-    }
-
-    public Pattern getPattern() {
-        if (pattern == null)
-            pattern = Pattern.compile(patternString);
-        return pattern;
-    }
-
-    public String getPatternString() {
-        return patternString;
-    }
-
-    public void remove() {
-        relation().deleter().patternStringEq(patternString).execute();
-        cache.remove(this);
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.kt b/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.kt
new file mode 100644
index 00000000..6fd1be36
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/data/ExtractionWord.kt
@@ -0,0 +1,54 @@
+package net.lacolaco.smileessence.data
+
+import com.github.gfx.android.orma.annotation.PrimaryKey
+import com.github.gfx.android.orma.annotation.Table
+
+import java.util.*
+import java.util.regex.Pattern
+
+@Table
+class ExtractionWord {
+    @PrimaryKey
+    lateinit var patternString: String
+
+    val pattern: Pattern by lazy {
+        Pattern.compile(patternString)
+    }
+
+    constructor()
+
+    private constructor(patternString: String) {
+        this.patternString = patternString
+    }
+
+    fun remove() {
+        relation().deleter().patternStringEq(patternString).execute()
+        cache!!.remove(this)
+    }
+
+    companion object {
+        private var cache: MutableSet<ExtractionWord>? = null
+
+        @Synchronized
+        fun cached(): Collection<ExtractionWord> {
+            return cache ?: throw IllegalStateException("extraction pattern not loaded")
+        }
+
+        @Synchronized
+        fun load() {
+            cache = HashSet(OrmaHolder.orma.selectFromExtractionWord().toList())
+        }
+
+        private fun relation(): ExtractionWord_Relation {
+            return OrmaHolder.orma.relationOfExtractionWord()
+        }
+
+        @Synchronized
+        fun add(patternString: String): ExtractionWord {
+            val extractionWord = ExtractionWord(patternString)
+            relation().upserter().execute(extractionWord)
+            cache!!.add(extractionWord)
+            return extractionWord
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.java b/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.java
deleted file mode 100644
index daa2a443..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.data;
-
-import android.graphics.Bitmap;
-import android.util.LruCache;
-import com.android.volley.Cache;
-import com.android.volley.RequestQueue;
-import com.android.volley.toolbox.*;
-import net.lacolaco.smileessence.Application;
-
-public class ImageCache {
-    private static ImageCache instance = new ImageCache();
-    private ImageLoader imageLoader;
-
-    private ImageCache() {
-        int cacheSizeInBytes = 64 * 1024 * 1024; // 64MB
-        Cache diskCache = new DiskBasedCache(Application.getInstance().getCacheDir(), cacheSizeInBytes);
-        RequestQueue requestQueue = new RequestQueue(diskCache, new BasicNetwork(new HurlStack()));
-        imageLoader = new ImageLoader(requestQueue, new ImageLruCache());
-        requestQueue.start();
-    }
-
-    public static ImageLoader getImageLoader() { return instance.imageLoader; }
-
-    private static class ImageLruCache implements ImageLoader.ImageCache {
-        private LruCache<String, Bitmap> cache;
-
-        private ImageLruCache() {
-            cache = new LruCache<>(4 * 1024 * 1024); // 4MB
-        }
-
-        @Override
-        public Bitmap getBitmap(String url) {
-            return cache.get(url);
-        }
-
-        @Override
-        public void putBitmap(String url, Bitmap bitmap) {
-            cache.put(url, bitmap);
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.kt b/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.kt
new file mode 100644
index 00000000..d7b4eeac
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/data/ImageCache.kt
@@ -0,0 +1,64 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.data
+
+import android.graphics.Bitmap
+import android.util.LruCache
+import com.android.volley.Cache
+import com.android.volley.RequestQueue
+import com.android.volley.toolbox.*
+import net.lacolaco.smileessence.Application
+
+class ImageCache private constructor() {
+    private val imageLoader: ImageLoader
+
+    init {
+        val cacheSizeInBytes = 64 * 1024 * 1024 // 64MB
+        val diskCache = DiskBasedCache(Application.getInstance().cacheDir, cacheSizeInBytes)
+        val requestQueue = RequestQueue(diskCache, BasicNetwork(HurlStack()))
+        imageLoader = ImageLoader(requestQueue, ImageLruCache())
+        requestQueue.start()
+    }
+
+    private class ImageLruCache : ImageLoader.ImageCache {
+        private val cache: LruCache<String, Bitmap> = LruCache(4 * 1024 * 1024) // 4MB
+
+        override fun getBitmap(url: String): Bitmap? {
+            return cache.get(url)
+        }
+
+        override fun putBitmap(url: String, bitmap: Bitmap) {
+            cache.put(url, bitmap)
+        }
+    }
+
+    companion object {
+        private val instance = ImageCache()
+
+        fun getImageLoader(): ImageLoader {
+            return instance.imageLoader
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.java b/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.java
deleted file mode 100644
index 5fd41c0c..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package net.lacolaco.smileessence.data;
-
-import android.content.Context;
-import com.github.gfx.android.orma.AccessThreadConstraint;
-
-public class OrmaHolder {
-    private static OrmaDatabase ORMA;
-
-    public static void initialize(Context context) {
-        ORMA = OrmaDatabase
-                .builder(context)
-                .writeOnMainThread(AccessThreadConstraint.WARNING)
-                .build();
-    }
-
-    public static OrmaDatabase getORMA() {
-        return ORMA;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.kt b/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.kt
new file mode 100644
index 00000000..f05f4def
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/data/OrmaHolder.kt
@@ -0,0 +1,16 @@
+package net.lacolaco.smileessence.data
+
+import android.content.Context
+import com.github.gfx.android.orma.AccessThreadConstraint
+
+object OrmaHolder {
+    lateinit var orma: OrmaDatabase
+        private set
+
+    fun initialize(context: Context) {
+        orma = OrmaDatabase
+                .builder(context)
+                .writeOnMainThread(AccessThreadConstraint.WARNING)
+                .build()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/PostState.java b/app/src/main/java/net/lacolaco/smileessence/data/PostState.java
deleted file mode 100644
index 4bbd83a4..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/PostState.java
+++ /dev/null
@@ -1,184 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.data;
-
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.view.DialogHelper;
-import twitter4j.StatusUpdate;
-
-public class PostState {
-    private String text = "";
-    private Tweet inReplyTo;
-    private String mediaFilePath = "";
-    private boolean directMessage = false;
-    private OnPostStateChangeListener listener;
-    private int selectionStart, selectionEnd;
-
-    public Tweet getInReplyTo() {
-        return inReplyTo;
-    }
-
-    public String getMediaFilePath() {
-        return mediaFilePath;
-    }
-
-    public int getSelectionEnd() {
-        if (selectionEnd < 0) {
-            return text.length();
-        }
-        return selectionEnd;
-    }
-
-    public int getSelectionStart() {
-        if (selectionStart < 0) {
-            return text.length();
-        }
-        return selectionStart;
-    }
-
-    public String getText() {
-        return text;
-    }
-
-    public PostState setListener(OnPostStateChangeListener listener) {
-        this.listener = listener;
-        return this;
-    }
-
-    public PostStateTransaction beginTransaction() {
-        return new PostStateTransaction(this);
-    }
-
-    public void removeListener() {
-        this.listener = null;
-    }
-
-    /**
-     * Convert to StatusUpdate for tweet.
-     *
-     * @return StatusUpdate
-     */
-    public StatusUpdate toStatusUpdate() {
-        StatusUpdate su = new StatusUpdate(getText());
-        if (getInReplyTo() != null) {
-            su.setInReplyToStatusId(getInReplyTo().getId());
-        }
-        return su;
-    }
-
-    private PostState copy(PostState another) {
-        this.text = another.text;
-        this.inReplyTo = another.getInReplyTo();
-        this.mediaFilePath = another.mediaFilePath;
-        this.directMessage = another.directMessage;
-        this.selectionStart = another.selectionStart;
-        this.selectionEnd = another.selectionEnd;
-        this.listener = another.listener;
-        return this;
-    }
-
-    private void postStateChange() {
-        if (listener != null) {
-            listener.onPostStateChange(this);
-        }
-    }
-
-    // -------------------------- INNER CLASSES --------------------------
-
-    public interface OnPostStateChangeListener {
-
-        void onPostStateChange(PostState postState);
-    }
-
-    public static class PostStateTransaction {
-        private PostState origState, state;
-
-        private PostStateTransaction(PostState state) {
-            this.origState = state;
-            this.state = new PostState().copy(state);
-        }
-
-        public PostStateTransaction setText(String text) {
-            state.text = text;
-            return this;
-        }
-
-        public PostStateTransaction appendText(String text) {
-            state.text = state.text + text;
-            return this;
-        }
-
-        public PostStateTransaction insertText(int index, String text) {
-            StringBuilder builder = new StringBuilder(state.text);
-            builder.insert(index, text);
-            state.text = builder.toString();
-            return this;
-        }
-
-        public PostStateTransaction setInReplyTo(Tweet inReplyTo) {
-            state.inReplyTo = inReplyTo;
-            return this;
-        }
-
-        public PostStateTransaction setMediaFilePath(String mediaFilePath) {
-            state.mediaFilePath = mediaFilePath;
-            return this;
-        }
-
-        public PostStateTransaction setCursor(int cursor) {
-            state.selectionStart = state.selectionEnd = cursor;
-            return this;
-        }
-
-        public PostStateTransaction setSelection(int start, int end) {
-            state.selectionStart = start;
-            state.selectionEnd = end;
-            return this;
-        }
-
-        public PostStateTransaction clear() {
-            state.text = "";
-            state.selectionStart = state.selectionEnd = 0;
-            state.inReplyTo = null;
-            return this;
-        }
-
-        public void commit() {
-            origState.copy(state).postStateChange();
-        }
-
-        public void commitWithOpen(MainActivity activity) {
-            DialogHelper.closeAll(activity);
-            origState.copy(state).postStateChange();
-            activity.openPostPage();
-        }
-
-        public PostStateTransaction moveCursor(int length) {
-            int cursor = state.selectionEnd + length;
-            return setCursor(cursor);
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt b/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt
new file mode 100644
index 00000000..4bc07443
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt
@@ -0,0 +1,167 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.data
+
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.view.DialogHelper
+import twitter4j.StatusUpdate
+
+class PostState {
+    var text = ""
+        private set
+    var inReplyTo: Tweet? = null
+        private set
+    var mediaFilePath = ""
+        private set
+    private var listener: OnPostStateChangeListener? = null
+    var selectionStart: Int = 0
+        get() {
+            return if (field < 0) {
+                text.length
+            } else field
+        }
+    var selectionEnd: Int = 0
+        get() {
+            return if (field < 0) {
+                text.length
+            } else field
+        }
+
+    fun setListener(listener: OnPostStateChangeListener): PostState {
+        this.listener = listener
+        return this
+    }
+
+    fun beginTransaction(): PostStateTransaction {
+        return PostStateTransaction(this)
+    }
+
+    fun removeListener() {
+        this.listener = null
+    }
+
+    /**
+     * Convert to StatusUpdate for tweet.
+     *
+     * @return StatusUpdate
+     */
+    fun toStatusUpdate(): StatusUpdate {
+        val su = StatusUpdate(text)
+        if (inReplyTo != null) {
+            su.inReplyToStatusId = inReplyTo!!.id
+        }
+        return su
+    }
+
+    private fun copy(another: PostState): PostState {
+        this.text = another.text
+        this.inReplyTo = another.inReplyTo
+        this.mediaFilePath = another.mediaFilePath
+        this.selectionStart = another.selectionStart
+        this.selectionEnd = another.selectionEnd
+        this.listener = another.listener
+        return this
+    }
+
+    private fun postStateChange() {
+        if (listener != null) {
+            listener!!.onPostStateChange(this)
+        }
+    }
+
+    // -------------------------- INNER CLASSES --------------------------
+
+    interface OnPostStateChangeListener {
+
+        fun onPostStateChange(postState: PostState)
+    }
+
+    class PostStateTransaction constructor(private val origState: PostState) {
+        private val state: PostState = PostState().copy(origState)
+
+        fun setText(text: String): PostStateTransaction {
+            state.text = text
+            return this
+        }
+
+        fun appendText(text: String): PostStateTransaction {
+            state.text = state.text + text
+            return this
+        }
+
+        fun insertText(index: Int, text: String): PostStateTransaction {
+            val builder = StringBuilder(state.text)
+            builder.insert(index, text)
+            state.text = builder.toString()
+            return this
+        }
+
+        fun setInReplyTo(inReplyTo: Tweet?): PostStateTransaction {
+            state.inReplyTo = inReplyTo
+            return this
+        }
+
+        fun setMediaFilePath(mediaFilePath: String): PostStateTransaction {
+            state.mediaFilePath = mediaFilePath
+            return this
+        }
+
+        fun setCursor(cursor: Int): PostStateTransaction {
+            state.selectionEnd = cursor
+            state.selectionStart = state.selectionEnd
+            return this
+        }
+
+        fun setSelection(start: Int, end: Int): PostStateTransaction {
+            state.selectionStart = start
+            state.selectionEnd = end
+            return this
+        }
+
+        fun clear(): PostStateTransaction {
+            state.text = ""
+            state.selectionEnd = 0
+            state.selectionStart = state.selectionEnd
+            state.inReplyTo = null
+            return this
+        }
+
+        fun commit() {
+            origState.copy(state).postStateChange()
+        }
+
+        fun commitWithOpen(activity: MainActivity) {
+            DialogHelper.closeAll(activity)
+            origState.copy(state).postStateChange()
+            activity.openPostPage()
+        }
+
+        fun moveCursor(length: Int): PostStateTransaction {
+            val cursor = state.selectionEnd + length
+            return setCursor(cursor)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.java b/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.java
deleted file mode 100644
index f2862151..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.java
+++ /dev/null
@@ -1,71 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-import net.lacolaco.smileessence.util.ListUtils;
-
-import java.util.Date;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-public class DirectMessage extends EntitySupport implements IdObject {
-    private static Map<Long, DirectMessage> storage = new HashMap<>();
-    private long id;
-    private User sender;
-    private User recipient;
-    private String text;
-    private Date createdAt;
-
-    private DirectMessage(twitter4j.DirectMessage st) {
-        update(st);
-    }
-
-    public synchronized static DirectMessage fetch(long statusId) {
-        return storage.get(statusId);
-    }
-
-    public synchronized static DirectMessage fromTwitter(twitter4j.DirectMessage st) {
-        DirectMessage t = fetch(st.getId());
-        if (t == null) {
-            t = new DirectMessage(st);
-            storage.put(st.getId(), t);
-        } else {
-            t.update(st);
-        }
-        return t;
-    }
-
-    public synchronized static List<DirectMessage> fromTwitter(List<twitter4j.DirectMessage> sts) {
-        return ListUtils.map(sts, DirectMessage::fromTwitter);
-    }
-
-    private void update(twitter4j.DirectMessage message) {
-        id = message.getId();
-        sender = User.fromTwitter(message.getSender());
-        recipient = User.fromTwitter(message.getRecipient());
-        text = extractText(message, false);
-        createdAt = message.getCreatedAt();
-
-        updateEntities(message);
-    }
-
-    @Override
-    public long getId() {
-        return id;
-    }
-
-    public User getSender() {
-        return sender;
-    }
-
-    public User getRecipient() {
-        return recipient;
-    }
-
-    public String getText() {
-        return text;
-    }
-
-    public Date getCreatedAt() {
-        return createdAt;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.kt b/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.kt
new file mode 100644
index 00000000..e89868f8
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/DirectMessage.kt
@@ -0,0 +1,44 @@
+package net.lacolaco.smileessence.entity
+
+import java.util.Date
+import java.util.HashMap
+
+class DirectMessage private constructor(message: twitter4j.DirectMessage) : EntitySupport(), IdObject {
+    override val id: Long = message.id
+    val sender: User = User.fromTwitter(message.sender)
+    val recipient: User = User.fromTwitter(message.recipient)
+    val text: String = extractText(message, false)
+    val createdAt: Date = message.createdAt
+
+    init {
+        updateEntities(message)
+    }
+
+    companion object {
+        private val storage = HashMap<Long, DirectMessage>()
+
+        @Synchronized
+        fun fetch(statusId: Long): DirectMessage? {
+            return storage[statusId]
+        }
+
+        @Synchronized
+        fun fromTwitter(st: twitter4j.DirectMessage): DirectMessage {
+            var t: DirectMessage? = fetch(st.id)
+            if (t == null) {
+                t = DirectMessage(st)
+                storage.put(st.id, t)
+            } else {
+                // Update local cache
+                User.fromTwitter(st.sender)
+                User.fromTwitter(st.recipient)
+            }
+            return t
+        }
+
+        @Synchronized
+        fun fromTwitter(sts: Iterable<twitter4j.DirectMessage>): List<DirectMessage> {
+            return sts.map { fromTwitter(it) }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.java b/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.java
deleted file mode 100644
index 9629bea2..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.java
+++ /dev/null
@@ -1,121 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-import net.lacolaco.smileessence.util.UIObservable;
-import twitter4j.*;
-
-import java.util.*;
-
-public abstract class EntitySupport extends UIObservable {
-    private List<String> mentions;
-    private List<String> hashtags;
-    private List<String> mediaUrls;
-    private List<String> urlsExpanded;
-    private List<String> symbols;
-
-    protected void updateEntities(twitter4j.EntitySupport status) {
-        mentions = extractMentions(status.getUserMentionEntities());
-        hashtags = extractHashtags(status.getHashtagEntities());
-        mediaUrls = extractMediaUrls(status.getMediaEntities());
-        urlsExpanded = extractExpandedUrls(status.getURLEntities());
-        symbols = extractSymbols(status.getSymbolEntities());
-    }
-
-    public List<String> getMentions() {
-        return mentions;
-    }
-
-    public List<String> getHashtags() {
-        return hashtags;
-    }
-
-    public List<String> getMediaUrls() {
-        return mediaUrls;
-    }
-
-    public List<String> getUrlsExpanded() {
-        return urlsExpanded;
-    }
-
-    public List<String> getSymbols() {
-        return symbols;
-    }
-
-    private List<String> extractMentions(UserMentionEntity[] entities) {
-        List<String> names = new ArrayList<>();
-        if (entities != null) {
-            for (UserMentionEntity entity : entities) {
-                names.add(entity.getScreenName());
-            }
-        }
-        return names;
-    }
-
-    private List<String> extractSymbols(SymbolEntity[] entities) {
-        List<String> names = new ArrayList<>();
-        if (entities != null) {
-            for (SymbolEntity entity : entities) {
-                names.add(entity.getText());
-            }
-        }
-        return names;
-    }
-
-    private List<String> extractExpandedUrls(URLEntity[] entities) {
-        List<String> names = new ArrayList<>();
-        if (entities != null) {
-            for (URLEntity entity : entities) {
-                names.add(entity.getExpandedURL());
-            }
-        }
-        return names;
-    }
-
-    private List<String> extractMediaUrls(MediaEntity[] entities) {
-        List<String> names = new ArrayList<>();
-        if (entities != null) {
-            for (MediaEntity entity : entities) {
-                if ("photo".equals(entity.getType())) {
-                    names.add(entity.getMediaURLHttps());
-                } else {
-                    names.add(entity.getExpandedURL());
-                }
-            }
-        }
-        return names;
-    }
-
-    private List<String> extractHashtags(HashtagEntity[] entities) {
-        List<String> names = new ArrayList<>();
-        if (entities != null) {
-            for (HashtagEntity entity : entities) {
-                names.add(entity.getText());
-            }
-        }
-        return names;
-    }
-
-    protected String extractText(twitter4j.Status status, boolean expand) {
-        return extractText(status, status.getText(), expand);
-    }
-
-    protected String extractText(twitter4j.DirectMessage status, boolean expand) {
-        return extractText(status, status.getText(), expand);
-    }
-
-    private String extractText(twitter4j.EntitySupport status, String text, boolean expand) {
-        SortedSet<twitter4j.URLEntity> set = new TreeSet<>((a, b) -> a.getStart() - b.getStart());
-        if (status.getURLEntities() != null) {
-            Collections.addAll(set, status.getURLEntities());
-        }
-        if (status.getMediaEntities() != null) {
-            Collections.addAll(set, status.getMediaEntities());
-        }
-
-        for (URLEntity entity : set) {
-            String newString = expand ? entity.getExpandedURL() : entity.getDisplayURL();
-            text = text.replaceFirst(entity.getText(), newString);
-        }
-
-        return text;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.kt b/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.kt
new file mode 100644
index 00000000..c1b3e4a3
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/EntitySupport.kt
@@ -0,0 +1,106 @@
+package net.lacolaco.smileessence.entity
+
+import net.lacolaco.smileessence.util.UIObservable
+import twitter4j.*
+
+import java.util.*
+
+abstract class EntitySupport : UIObservable() {
+    open lateinit var mentions: List<String>
+        protected set
+    open lateinit var hashtags: List<String>
+        protected set
+    open lateinit var mediaUrls: List<String>
+        protected set
+    open lateinit var urlsExpanded: List<String>
+        protected set
+    open lateinit var symbols: List<String>
+        protected set
+
+    protected fun updateEntities(status: twitter4j.EntitySupport) {
+        mentions = extractMentions(status.userMentionEntities)
+        hashtags = extractHashtags(status.hashtagEntities)
+        mediaUrls = extractMediaUrls(status.mediaEntities)
+        urlsExpanded = extractExpandedUrls(status.urlEntities)
+        symbols = extractSymbols(status.symbolEntities)
+    }
+
+    private fun extractMentions(entities: Array<UserMentionEntity>?): List<String> {
+        val names = ArrayList<String>()
+        if (entities != null) {
+            for (entity in entities) {
+                names.add(entity.screenName)
+            }
+        }
+        return names
+    }
+
+    private fun extractSymbols(entities: Array<SymbolEntity>?): List<String> {
+        val names = ArrayList<String>()
+        if (entities != null) {
+            for (entity in entities) {
+                names.add(entity.text)
+            }
+        }
+        return names
+    }
+
+    private fun extractExpandedUrls(entities: Array<URLEntity>?): List<String> {
+        val names = ArrayList<String>()
+        if (entities != null) {
+            for (entity in entities) {
+                names.add(entity.expandedURL)
+            }
+        }
+        return names
+    }
+
+    private fun extractMediaUrls(entities: Array<MediaEntity>?): List<String> {
+        val names = ArrayList<String>()
+        if (entities != null) {
+            for (entity in entities) {
+                if ("photo" == entity.type) {
+                    names.add(entity.mediaURLHttps)
+                } else {
+                    names.add(entity.expandedURL)
+                }
+            }
+        }
+        return names
+    }
+
+    private fun extractHashtags(entities: Array<HashtagEntity>?): List<String> {
+        val names = ArrayList<String>()
+        if (entities != null) {
+            for (entity in entities) {
+                names.add(entity.text)
+            }
+        }
+        return names
+    }
+
+    protected fun extractText(status: twitter4j.Status, expand: Boolean): String {
+        return extractText(status, status.text, expand)
+    }
+
+    protected fun extractText(status: twitter4j.DirectMessage, expand: Boolean): String {
+        return extractText(status, status.text, expand)
+    }
+
+    private fun extractText(status: twitter4j.EntitySupport, text: String, expand: Boolean): String {
+        val set = TreeSet<twitter4j.URLEntity> { a, b -> a.start - b.start }
+        if (status.urlEntities != null) {
+            Collections.addAll(set, *status.urlEntities)
+        }
+        if (status.mediaEntities != null) {
+            Collections.addAll(set, *status.mediaEntities)
+        }
+
+        var t = text
+        for (entity in set) {
+            val newString = if (expand) entity.expandedURL else entity.displayURL
+            t = t.replaceFirst(entity.text.toRegex(), newString)
+        }
+        return t
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/Event.java b/app/src/main/java/net/lacolaco/smileessence/entity/Event.java
deleted file mode 100644
index e2002cb9..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/Event.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-import java.util.Date;
-
-public class Event {
-    private final Date createdAt;
-    private final EnumEvent event;
-    private final User source;
-    private final Tweet targetObject;
-
-    public Event(EnumEvent e, User s) {
-        this(e, s, null);
-    }
-
-    public Event(EnumEvent e, User s, Tweet t) {
-        event = e;
-        createdAt = new Date();
-        source = s;
-        targetObject = t;
-    }
-
-    public Date getCreatedAt() {
-        return createdAt;
-    }
-
-    public EnumEvent getEvent() {
-        return event;
-    }
-
-    public User getSource() {
-        return source;
-    }
-
-    public Tweet getTargetObject() {
-        return targetObject;
-    }
-
-    public String getFormattedString() {
-        return String.format(event.getFormat(), source.getScreenName());
-    }
-
-    public enum EnumEvent {
-        FAVORITED("Favorited by %s"),
-        UNFAVORITED("Unfavorited by %s"),
-        RETWEETED("Retweeted by %s"),
-        MENTIONED("Replied by %s"),
-        FOLLOWED("Followed by %s"),
-        BLOCKED("Blocked by %s"),
-        UNBLOCKED("Unblocked by %s"),
-        RECEIVE_MESSAGE("Received a direct message from %s");
-
-        private final String format;
-
-        EnumEvent(String f) {
-            format = f;
-        }
-
-        public String getFormat() {
-            return format;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/Event.kt b/app/src/main/java/net/lacolaco/smileessence/entity/Event.kt
new file mode 100644
index 00000000..d7d7a9cd
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/Event.kt
@@ -0,0 +1,20 @@
+package net.lacolaco.smileessence.entity
+
+import java.util.Date
+
+class Event constructor(val event: EnumEvent, val source: User, val targetObject: Tweet? = null) {
+    val createdAt: Date = Date()
+    val formattedString: String
+        get() = String.format(event.format, source.screenName)
+
+    enum class EnumEvent(val format: String) {
+        FAVORITED("Favorited by %s"),
+        UNFAVORITED("Unfavorited by %s"),
+        RETWEETED("Retweeted by %s"),
+        MENTIONED("Replied by %s"),
+        FOLLOWED("Followed by %s"),
+        BLOCKED("Blocked by %s"),
+        UNBLOCKED("Unblocked by %s"),
+        RECEIVE_MESSAGE("Received a direct message from %s")
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.java b/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.java
deleted file mode 100644
index 444a627b..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-public interface IdObject {
-    long getId();
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.kt b/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.kt
new file mode 100644
index 00000000..eb08d55f
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/IdObject.kt
@@ -0,0 +1,5 @@
+package net.lacolaco.smileessence.entity
+
+interface IdObject {
+    val id: Long
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/RBinding.java b/app/src/main/java/net/lacolaco/smileessence/entity/RBinding.kt
index 5ade81b2..1a25cdd5 100644
--- a/app/src/main/java/net/lacolaco/smileessence/entity/RBinding.java
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/RBinding.kt
@@ -1,6 +1,6 @@
-package net.lacolaco.smileessence.entity;
+package net.lacolaco.smileessence.entity
 
-public enum RBinding {
+enum class RBinding {
     // Tweet
     REACTION_COUNT,
     FAVORITERS,
@@ -8,5 +8,5 @@ public enum RBinding {
 
     // User
     BASIC,
-    DETAIL,;
+    DETAIL
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.java b/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.java
deleted file mode 100644
index 8fcd0acd..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-public class SavedSearch implements IdObject {
-    private long id;
-    private String query;
-
-    private SavedSearch(long id, String query) {
-        this.id = id;
-        this.query = query;
-    }
-
-    public synchronized static SavedSearch fromTwitter(twitter4j.SavedSearch obj) {
-        return new SavedSearch(obj.getId(), obj.getQuery());
-    }
-
-    @Override
-    public long getId() {
-        return id;
-    }
-
-    public String getQuery() {
-        return query;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.kt b/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.kt
new file mode 100644
index 00000000..318a2184
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/SavedSearch.kt
@@ -0,0 +1,10 @@
+package net.lacolaco.smileessence.entity
+
+class SavedSearch private constructor(override val id: Long, val query: String) : IdObject {
+    companion object {
+        @Synchronized
+        fun fromTwitter(obj: twitter4j.SavedSearch): SavedSearch {
+            return SavedSearch(obj.id, obj.query)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.java b/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.java
deleted file mode 100644
index c79c58ef..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.java
+++ /dev/null
@@ -1,281 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-import android.net.Uri;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.twitter.task.Tweets;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import net.lacolaco.smileessence.util.ListUtils;
-import twitter4j.Status;
-
-import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
-
-public class Tweet extends EntitySupport implements IdObject {
-    private static Map<Long, Tweet> storage = new HashMap<>();
-    private final long id;
-    private User user;
-    private String text;
-    private Date createdAt;
-    private String source;
-    private boolean isRetweet;
-    private Tweet retweetedTweet;
-    private long inReplyToStatusId;
-    private int favoriteCount;
-    private int retweetCount;
-    private Set<Long> favoriters;
-    private Map<Long, Long> retweets;
-
-    private Tweet(long id) {
-        this.id = id;
-    }
-
-    public synchronized static Tweet fetch(long statusId) {
-        return storage.get(statusId);
-    }
-
-    public synchronized static BackgroundTask<Tweet, Void> fetchTask(long statusId, Account account) {
-        Tweet tweet = fetch(statusId);
-        if (tweet != null) {
-            return new BackgroundTask<Tweet, Void>() {
-                @Override
-                protected Tweet doInBackground() throws Exception {
-                    return tweet;
-                }
-            };
-        } else {
-            return new Tweets.GetTask(account, statusId);
-        }
-    }
-
-    public synchronized static Tweet fromTwitter(final twitter4j.Status st, long myUserId) {
-        Tweet t = fetch(st.getId());
-        if (t == null) {
-            t = new Tweet(st.getId());
-            storage.put(st.getId(), t);
-        }
-
-        t.update(st, myUserId);
-        return t;
-    }
-
-    public synchronized static List<Tweet> fromTwitter(List<Status> sts, long myUserId) {
-        return ListUtils.map(sts, st -> fromTwitter(st, myUserId));
-    }
-
-    @Override
-    protected void finalize() throws Throwable {
-        try {
-            super.finalize();
-        } finally {
-            Tweet original = getRetweetedTweet();
-            if (original != null) {
-                original.removeRetweet(getId());
-            }
-        }
-    }
-
-    private void update(twitter4j.Status status, long myUserId) {
-        if (id != status.getId())
-            throw new IllegalStateException("Invalid update");
-        user = User.fromTwitter(status.getUser());
-        createdAt = status.getCreatedAt();
-        source = status.getSource();
-        isRetweet = status.isRetweet();
-
-        if (!isRetweet) {
-            text = extractText(status, false);
-            inReplyToStatusId = status.getInReplyToStatusId();
-            updateEntities(status);
-            if (favoriters == null) favoriters = Collections.newSetFromMap(new ConcurrentHashMap<>());
-            if (retweets == null) retweets = new ConcurrentHashMap<>();
-
-            if (favoriteCount != status.getFavoriteCount() || retweetCount != status.getRetweetCount()) {
-                favoriteCount = status.getFavoriteCount();
-                retweetCount = status.getRetweetCount();
-
-                notifyChange(RBinding.REACTION_COUNT);
-            }
-
-            if (status.isFavorited()) {
-                addFavoriter(myUserId);
-            } else {
-                removeFavoriter(myUserId);
-            }
-            if (status.getCurrentUserRetweetId() > 0) {
-                addRetweet(myUserId, status.getCurrentUserRetweetId());
-            }
-        } else {
-            retweetedTweet = Tweet.fromTwitter(status.getRetweetedStatus(), myUserId);
-            retweetedTweet.addRetweet(this);
-            if (status.isFavorited()) {
-                retweetedTweet.addFavoriter(myUserId);
-            }
-            if (status.getCurrentUserRetweetId() > 0) {
-                retweetedTweet.addRetweet(myUserId, status.getCurrentUserRetweetId());
-            }
-        }
-    }
-
-    public String getTwitterUrl() {
-        return String.format("https://twitter.com/%s/status/%s", getUser().getScreenName(), id);
-    }
-
-    @Override
-    public long getId() {
-        return id;
-    }
-
-    public User getUser() {
-        return user;
-    }
-
-    public String getText() {
-        return getOriginalTweet().text;
-    }
-
-    public Date getCreatedAt() {
-        return createdAt;
-    }
-
-    public String getSource() {
-        return source;
-    }
-
-    public boolean isRetweet() {
-        return isRetweet;
-    }
-
-    public Tweet getRetweetedTweet() {
-        return retweetedTweet;
-    }
-
-    public Tweet getOriginalTweet() {
-        if (isRetweet()) {
-            return getRetweetedTweet();
-        } else {
-            return this;
-        }
-    }
-
-    public int getFavoriteCount() {
-        return getOriginalTweet().favoriteCount;
-    }
-
-    public int getRetweetCount() {
-        return getOriginalTweet().retweetCount;
-    }
-
-    public long getInReplyToStatusId() {
-        return getOriginalTweet().inReplyToStatusId;
-    }
-
-    public boolean isFavoritedBy(long id) {
-        return getOriginalTweet().favoriters.contains(id);
-    }
-
-    public Set<Long> getFavoriters() {
-        return getOriginalTweet().favoriters;
-    }
-
-    public boolean addFavoriter(long id) {
-        boolean changed = getOriginalTweet().favoriters.add(id);
-        if (changed) notifyChange(RBinding.FAVORITERS);
-        return changed;
-    }
-
-    public boolean removeFavoriter(long id) {
-        boolean changed = getOriginalTweet().favoriters.remove(id);
-        if (changed) notifyChange(RBinding.FAVORITERS);
-        return changed;
-    }
-
-    public boolean isRetweetedBy(long id) {
-        return getOriginalTweet().retweets.get(id) != null;
-    }
-
-    public long getRetweetIdBy(long id) {
-        return getOriginalTweet().retweets.get(id);
-    }
-
-    public Map<Long, Long> getRetweets() {
-        return getOriginalTweet().retweets;
-    }
-
-    public boolean addRetweet(Tweet retweet) {
-        return addRetweet(retweet.getUser().getId(), retweet.getId());
-    }
-
-    public boolean addRetweet(long uid, long sid) {
-        Long result = getOriginalTweet().retweets.put(uid, sid);
-        boolean changed = result == null || result != sid;
-        if (changed) notifyChange(RBinding.RETWEETERS);
-        return changed;
-    }
-
-    private boolean removeRetweet(long sid) {
-        boolean changed = getOriginalTweet().retweets.values().remove(sid);
-        if (changed) notifyChange(RBinding.RETWEETERS);
-        return changed;
-    }
-
-    // helper methods::
-    public List<Long> getEmbeddedStatusIDs() {
-        ArrayList<Long> list = new ArrayList<>();
-        for (String url : getUrlsExpanded()) {
-            Uri uri = Uri.parse(url);
-            if ("twitter.com".equals(uri.getHost())) {
-                String[] arr = uri.toString().split("/");
-                if (arr.length > 2 && "status".equals(arr[arr.length - 2])) {
-                    list.add(Long.parseLong(arr[arr.length - 1].split("\\?")[0]));
-                }
-            }
-        }
-        return list;
-    }
-
-    // override EntitySupport
-    @Override
-    public List<String> getMentions() {
-        if (isRetweet) {
-            return getOriginalTweet().getMentions();
-        } else {
-            return super.getMentions();
-        }
-    }
-
-    @Override
-    public List<String> getHashtags() {
-        if (isRetweet) {
-            return getOriginalTweet().getHashtags();
-        } else {
-            return super.getHashtags();
-        }
-    }
-
-    @Override
-    public List<String> getMediaUrls() {
-        if (isRetweet) {
-            return getOriginalTweet().getMediaUrls();
-        } else {
-            return super.getMediaUrls();
-        }
-    }
-
-    @Override
-    public List<String> getUrlsExpanded() {
-        if (isRetweet) {
-            return getOriginalTweet().getUrlsExpanded();
-        } else {
-            return super.getUrlsExpanded();
-        }
-    }
-
-    @Override
-    public List<String> getSymbols() {
-        if (isRetweet) {
-            return getOriginalTweet().getSymbols();
-        } else {
-            return super.getSymbols();
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.kt b/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.kt
new file mode 100644
index 00000000..437e69c7
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/Tweet.kt
@@ -0,0 +1,197 @@
+package net.lacolaco.smileessence.entity
+
+import android.net.Uri
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.twitter.task.Tweets
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.Status
+
+import java.util.*
+import java.util.concurrent.ConcurrentHashMap
+
+class Tweet private constructor(st: twitter4j.Status, myUserId: Long) : EntitySupport(), IdObject {
+    override val id: Long = st.id
+    val user: User = User.fromTwitter(st.user)
+    val text: String = extractText(st, false)
+        get() {
+            return if (isRetweet) originalTweet.text else field
+        }
+    val createdAt: Date = st.createdAt
+    val source: String = st.source
+    val isRetweet: Boolean = st.isRetweet
+    val retweetedTweet: Tweet? = if (st.isRetweet) Tweet.fromTwitter(st.retweetedStatus, myUserId) else null
+    val originalTweet: Tweet
+        get() = retweetedTweet ?: this
+    val inReplyToStatusId: Long = st.inReplyToStatusId
+        get() = if (isRetweet) originalTweet.inReplyToStatusId else field
+    var favoriteCount: Int = st.favoriteCount
+        get() = if (isRetweet) originalTweet.originalTweet.favoriteCount else field
+        private set
+    var retweetCount: Int = st.retweetCount
+        get() = if (isRetweet) originalTweet.originalTweet.retweetCount else field
+        private set
+    private val favoriters: MutableSet<Long> = Collections.newSetFromMap(ConcurrentHashMap())
+    private val retweets: MutableMap<Long, Long> = ConcurrentHashMap()
+
+    protected fun finalize() {
+        retweetedTweet?.retweets?.remove(id)
+    }
+
+    init {
+        updateEntities(st)
+        update(st, myUserId)
+    }
+
+    private fun update(status: twitter4j.Status, myUserId: Long) {
+        User.fromTwitter(status.user)
+        if (retweetedTweet != null) {
+            Tweet.fromTwitter(status.retweetedStatus, myUserId)
+            if (status.isFavorited) {
+                retweetedTweet.favoriters.add(myUserId)
+            }
+            if (status.currentUserRetweetId > 0) {
+                retweetedTweet.retweets.put(myUserId, status.currentUserRetweetId)
+            }
+        } else {
+            if (favoriteCount != status.favoriteCount || retweetCount != status.retweetCount) {
+                favoriteCount = status.favoriteCount
+                retweetCount = status.retweetCount
+                notifyChange(RBinding.REACTION_COUNT)
+            }
+
+            if (status.isFavorited)
+                favoriters.add(myUserId)
+            else
+                favoriters.remove(myUserId)
+            if (status.currentUserRetweetId > 0)
+                retweets.put(myUserId, status.currentUserRetweetId)
+        }
+    }
+
+    val twitterUrl: String
+        get() = String.format("https://twitter.com/%s/status/%s", user.screenName, id)
+
+    fun isFavoritedBy(id: Long): Boolean {
+        return originalTweet.favoriters.contains(id)
+    }
+
+    fun addFavoriter(id: Long): Boolean {
+        val changed = originalTweet.favoriters.add(id)
+        if (changed) notifyChange(RBinding.FAVORITERS)
+        return changed
+    }
+
+    fun removeFavoriter(id: Long): Boolean {
+        val changed = originalTweet.favoriters.remove(id)
+        if (changed) notifyChange(RBinding.FAVORITERS)
+        return changed
+    }
+
+    fun isRetweetedBy(id: Long): Boolean {
+        return originalTweet.retweets[id] != null
+    }
+
+    fun getRetweetIdBy(id: Long): Long {
+        return originalTweet.retweets[id]!!
+    }
+
+    // helper methods::
+    val embeddedStatusIDs: List<Long>
+        get() {
+            val list = ArrayList<Long>()
+            for (url in urlsExpanded) {
+                val uri = Uri.parse(url)
+                if ("twitter.com" == uri.host) {
+                    val arr = uri.toString().split("/".toRegex()).dropLastWhile({ it.isEmpty() }).toTypedArray()
+                    if (arr.size > 2 && "status" == arr[arr.size - 2]) {
+                        list.add(java.lang.Long.parseLong(arr[arr.size - 1].split("\\?".toRegex()).dropLastWhile({ it.isEmpty() }).toTypedArray()[0]))
+                    }
+                }
+            }
+            return list
+        }
+
+    // override EntitySupport
+    override var mentions: List<String>
+        get() = if (isRetweet) originalTweet.mentions else super.mentions
+        set(value) {
+            super.mentions = value
+        }
+
+    override var hashtags: List<String>
+        get() = if (isRetweet) originalTweet.hashtags else super.hashtags
+        set(value) {
+            super.hashtags = value
+        }
+
+    override var mediaUrls: List<String>
+        get() = if (isRetweet) {
+            originalTweet.mediaUrls
+        } else {
+            super.mediaUrls
+        }
+        set(value) {
+            super.mediaUrls = value
+        }
+
+    override var urlsExpanded: List<String>
+        get() = if (isRetweet) {
+            originalTweet.urlsExpanded
+        } else {
+            super.urlsExpanded
+        }
+        set(value) {
+            super.urlsExpanded = value
+        }
+
+    override var symbols: List<String>
+        get() = if (isRetweet) {
+            originalTweet.symbols
+        } else {
+            super.symbols
+        }
+        set(value) {
+            super.symbols = value
+        }
+
+    companion object {
+        private val storage = HashMap<Long, Tweet>()
+
+        @Synchronized
+        fun fetch(statusId: Long): Tweet? {
+            return storage[statusId]
+        }
+
+        @Synchronized
+        fun fetchTask(statusId: Long, account: Account): BackgroundTask<Tweet, Void> {
+            val tweet = fetch(statusId)
+            return if (tweet != null) {
+                object : BackgroundTask<Tweet, Void>() {
+                    @Throws(Exception::class)
+                    override fun doInBackground(): Tweet {
+                        return tweet
+                    }
+                }
+            } else {
+                Tweets.GetTask(account, statusId)
+            }
+        }
+
+        @Synchronized
+        fun fromTwitter(st: twitter4j.Status, myUserId: Long): Tweet {
+            var t = fetch(st.id)
+            if (t == null) {
+                t = Tweet(st, myUserId)
+                storage.put(st.id, t)
+            } else {
+                t.update(st, myUserId)
+            }
+            return t
+        }
+
+        @Synchronized
+        fun fromTwitter(sts: List<Status>, myUserId: Long): List<Tweet> {
+            return sts.map { st -> fromTwitter(st, myUserId) }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/User.java b/app/src/main/java/net/lacolaco/smileessence/entity/User.java
deleted file mode 100644
index abc2c047..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/entity/User.java
+++ /dev/null
@@ -1,183 +0,0 @@
-package net.lacolaco.smileessence.entity;
-
-import net.lacolaco.smileessence.util.UIObservable;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class User extends UIObservable implements IdObject {
-    private static Map<Long, User> storage = new HashMap<>();
-    private long id;
-    private boolean isProtected;
-    private String screenName;
-    private String name;
-    private String profileImageUrl;
-    private String profileBannerUrl;
-    private String description;
-    private String location;
-    private String url;
-    private int favoritesCount;
-    private int statusesCount;
-    private int friendsCount;
-    private int followersCount;
-    private boolean isVerified;
-
-    private User() {
-    }
-
-    public synchronized static User fetch(long userId) {
-        return storage.get(userId);
-    }
-
-    public synchronized static User fromTwitter(final twitter4j.User st) {
-        User u = fetch(st.getId());
-        if (u == null) {
-            u = new User();
-            storage.put(st.getId(), u);
-        }
-
-        u.update(st);
-        return u;
-    }
-
-    // only for initialization; DO NOT have reference for this object
-    public synchronized static User _makeSkeleton(long id, String screenName) {
-        User u = fetch(id);
-        if (u != null) {
-            return u;
-        } else {
-            u = new User();
-            u.id = id;
-            u.screenName = screenName;
-            storage.put(id, u);
-            return u;
-        }
-    }
-
-    private void update(twitter4j.User user) {
-        id = user.getId();
-
-        if (isProtected() != user.isProtected() ||
-                getScreenName() == null || !getScreenName().equals(user.getScreenName()) ||
-                getName() == null || !getName().equals(user.getName()) ||
-                profileImageUrl == null || !profileImageUrl.equals(user.getProfileImageURLHttps())) {
-            isProtected = user.isProtected();
-            if (user.getScreenName() != null)
-                screenName = user.getScreenName();
-            if (user.getName() != null)
-                name = user.getName();
-            if (user.getProfileImageURLHttps() != null)
-                profileImageUrl = user.getProfileImageURLHttps();
-
-            notifyChange(RBinding.BASIC);
-        }
-
-        if (getProfileBannerUrl() == null || !getProfileBannerUrl().equals(user.getProfileBannerURL()) ||
-                getDescription() == null || !getDescription().equals(user.getDescription()) ||
-                getLocation() == null || !getLocation().equals(user.getLocation()) ||
-                getUrl() == null || !getUrl().equals(user.getURL()) ||
-                getFavoritesCount() != user.getFavouritesCount() ||
-                getStatusesCount() != user.getStatusesCount() ||
-                getFriendsCount() != user.getFriendsCount() ||
-                getFollowersCount() != user.getFollowersCount()) {
-            isVerified = user.isVerified();
-            if (user.getProfileBannerURL() != null)
-                profileBannerUrl = user.getProfileBannerURL();
-            if (user.getDescription() != null)
-                description = user.getDescription();
-            if (user.getLocation() != null)
-                location = user.getLocation();
-            if (user.getURL() != null)
-                url = user.getURL();
-            if (user.getFavouritesCount() != -1)
-                favoritesCount = user.getFavouritesCount();
-            if (user.getStatusesCount() != -1)
-                statusesCount = user.getStatusesCount();
-            if (user.getFriendsCount() != -1)
-                friendsCount = user.getFriendsCount();
-            if (user.getFollowersCount() != -1)
-                followersCount = user.getFollowersCount();
-
-            notifyChange(RBinding.DETAIL);
-        }
-    }
-
-    @Override
-    public long getId() {
-        return id;
-    }
-
-    public boolean isProtected() {
-        return isProtected;
-    }
-
-    public String getScreenName() {
-        return screenName;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public String getProfileImageUrlOriginal() {
-        String original = profileImageUrl;
-        if (original != null) {
-            String url = original.substring(0, original.lastIndexOf("_"));
-            int extIndex = original.lastIndexOf(".");
-            if (extIndex > original.lastIndexOf("/")) {
-                url += original.substring(extIndex);
-            }
-            return url;
-        }
-        return null;
-    }
-
-    public String getProfileBannerUrl() {
-        return profileBannerUrl;
-    }
-
-    public String getDescription() {
-        return description;
-    }
-
-    public String getLocation() {
-        return location;
-    }
-
-    public String getUrl() {
-        return url;
-    }
-
-    public int getFavoritesCount() {
-        return favoritesCount;
-    }
-
-    public int getStatusesCount() {
-        return statusesCount;
-    }
-
-    public int getFriendsCount() {
-        return friendsCount;
-    }
-
-    public int getFollowersCount() {
-        return followersCount;
-    }
-
-    public boolean isVerified() {
-        return isVerified;
-    }
-
-    // helper methods
-    public String getUserHomeURL() {
-        return String.format("https://twitter.com/%s", getScreenName());
-    }
-
-    public String getAclogTimelineURL() {
-        return String.format("https://aclog.rhe.jp/%s/timeline", getScreenName());
-    }
-
-    public String getFormattedName() {
-        return screenName + " / " + name;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/entity/User.kt b/app/src/main/java/net/lacolaco/smileessence/entity/User.kt
new file mode 100644
index 00000000..6a92b54e
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/entity/User.kt
@@ -0,0 +1,136 @@
+package net.lacolaco.smileessence.entity
+
+import net.lacolaco.smileessence.util.UIObservable
+
+import java.util.HashMap
+
+class User private constructor(override val id: Long, screenName: String) : UIObservable(), IdObject {
+    var screenName = screenName
+        private set
+    var name: String? = null
+        private set
+    var profileImageUrl: String? = null
+        get() {
+            val original = field
+            if (original != null) {
+                var url = original.substring(0, original.lastIndexOf("_"))
+                val extIndex = original.lastIndexOf(".")
+                if (extIndex > original.lastIndexOf("/")) {
+                    url += original.substring(extIndex)
+                }
+                return url
+            }
+            return null
+        }
+        private set
+    var profileBannerUrl: String? = null
+        private set
+    var description: String? = null
+        private set
+    var location: String? = null
+        private set
+    var url: String? = null
+        private set
+    var favoritesCount: Int = 0
+        private set
+    var statusesCount: Int = 0
+        private set
+    var friendsCount: Int = 0
+        private set
+    var followersCount: Int = 0
+        private set
+    var isProtected: Boolean = false
+        private set
+    var isVerified: Boolean = false
+        private set
+
+    private fun update(user: twitter4j.User) {
+        if (isProtected != user.isProtected ||
+                screenName != user.screenName ||
+                name == null || name != user.name ||
+                this.profileImageUrl == null || this.profileImageUrl != user.profileImageURLHttps) {
+            isProtected = user.isProtected
+            if (user.screenName != null)
+                screenName = user.screenName
+            if (user.name != null)
+                name = user.name
+            if (user.profileImageURLHttps != null)
+                this.profileImageUrl = user.profileImageURLHttps
+
+            notifyChange(RBinding.BASIC)
+        }
+
+        if (profileBannerUrl == null || profileBannerUrl != user.profileBannerURL ||
+                description == null || description != user.description ||
+                location == null || location != user.location ||
+                url == null || url != user.url ||
+                favoritesCount != user.favouritesCount ||
+                statusesCount != user.statusesCount ||
+                friendsCount != user.friendsCount ||
+                followersCount != user.followersCount) {
+            isVerified = user.isVerified
+            if (user.profileBannerURL != null)
+                profileBannerUrl = user.profileBannerURL
+            if (user.description != null)
+                description = user.description
+            if (user.location != null)
+                location = user.location
+            if (user.url != null)
+                url = user.url
+            if (user.favouritesCount != -1)
+                favoritesCount = user.favouritesCount
+            if (user.statusesCount != -1)
+                statusesCount = user.statusesCount
+            if (user.friendsCount != -1)
+                friendsCount = user.friendsCount
+            if (user.followersCount != -1)
+                followersCount = user.followersCount
+
+            notifyChange(RBinding.DETAIL)
+        }
+    }
+
+    // helper methods
+    val userHomeURL: String
+        get() = String.format("https://twitter.com/%s", screenName)
+
+    val aclogTimelineURL: String
+        get() = String.format("https://aclog.rhe.jp/%s/timeline", screenName)
+
+    val formattedName: String
+        get() = screenName + " / " + name
+
+    companion object {
+        private val storage = HashMap<Long, User>()
+
+        @Synchronized
+        fun fetch(userId: Long): User? {
+            return storage[userId]
+        }
+
+        @Synchronized
+        fun fromTwitter(st: twitter4j.User): User {
+            var u: User? = fetch(st.id)
+            if (u == null) {
+                u = User(st.id, st.screenName)
+                storage.put(st.id, u)
+            }
+
+            u.update(st)
+            return u
+        }
+
+        // only for initialization; DO NOT have reference for this object
+        @Synchronized
+        fun _makeSkeleton(id: Long, screenName: String): User {
+            var u: User? = fetch(id)
+            if (u != null) {
+                return u
+            } else {
+                u = User(id, screenName)
+                storage.put(id, u)
+                return u
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/logging/Logger.java b/app/src/main/java/net/lacolaco/smileessence/logging/Logger.kt
index 675a14f1..7e898c1b 100644
--- a/app/src/main/java/net/lacolaco/smileessence/logging/Logger.java
+++ b/app/src/main/java/net/lacolaco/smileessence/logging/Logger.kt
@@ -22,45 +22,46 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.logging;
+package net.lacolaco.smileessence.logging
 
-import android.util.Log;
+import android.util.Log
 
-public class Logger {
+object Logger {
 
     // ------------------------------ FIELDS ------------------------------
 
-    private static final String TAG = "SmileEssence";
+    private val TAG = "SmileEssence"
 
     // -------------------------- STATIC METHODS --------------------------
 
-    public static void debug(Object message) {
-        Log.d(getTag(), String.valueOf(message));
+    fun debug(message: Any) {
+        Log.d(tag, message.toString())
     }
 
-    public static void info(Object message) {
-        Log.i(getTag(), String.valueOf(message));
+    fun info(message: Any) {
+        Log.i(tag, message.toString())
     }
 
-    public static void error(Object message) {
-        Log.e(getTag(), String.valueOf(message));
+    fun error(message: Any) {
+        Log.e(tag, message.toString())
     }
 
-    public static void warn(Object message) {
-        Log.w(getTag(), String.valueOf(message));
+    fun warn(message: Any) {
+        Log.w(tag, message.toString())
     }
 
-    public static void verbose(Object message) {
-        Log.v(getTag(), String.valueOf(message));
+    fun verbose(message: Any) {
+        Log.v(tag, message.toString())
     }
 
-    private static String getTag() {
-        StackTraceElement[] st = Thread.currentThread().getStackTrace();
-        for (int i = 0; i < st.length; ++i) {
-            if ("getTag".equals(st[i].getMethodName())) {
-                return st[i + 2].getClassName() + ":" + st[i + 2].getMethodName();
+    private val tag: String
+        get() {
+            val st = Thread.currentThread().stackTrace
+            for (i in st.indices) {
+                if ("getTag" == st[i].methodName) {
+                    return st[i + 2].className + ":" + st[i + 2].methodName
+                }
             }
+            return TAG
         }
-        return TAG;
-    }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.java b/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.java
deleted file mode 100644
index 9d500cd4..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.preference;
-
-import android.content.Context;
-import android.content.SharedPreferences;
-import net.lacolaco.smileessence.Application;
-
-public class InternalPreferenceHelper extends SharedPreferenceHelper {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private static final String FILE_NAME = "AppPreference";
-    private static final InternalPreferenceHelper instance = new InternalPreferenceHelper();
-
-    private InternalPreferenceHelper() {
-    }
-
-    public static InternalPreferenceHelper getInstance() {
-        return instance;
-    }
-
-    // --------------------------- OVERRIDE ---------------------------
-    @Override
-    protected SharedPreferences getPreferences() {
-        return Application.getInstance().getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.kt b/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.kt
new file mode 100644
index 00000000..1353eb2a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/preference/InternalPreferenceHelper.kt
@@ -0,0 +1,44 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.preference
+
+import android.content.Context
+import android.content.SharedPreferences
+import net.lacolaco.smileessence.Application
+
+class InternalPreferenceHelper private constructor() : SharedPreferenceHelper() {
+
+    // --------------------------- OVERRIDE ---------------------------
+    override val preferences: SharedPreferences
+        get() = Application.getInstance().getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE)
+
+    companion object {
+
+        // ------------------------------ FIELDS ------------------------------
+
+        private val FILE_NAME = "AppPreference"
+        val instance = InternalPreferenceHelper()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.java b/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.java
deleted file mode 100644
index 979dc732..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.java
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.preference;
-
-import android.content.SharedPreferences;
-import net.lacolaco.smileessence.Application;
-
-import java.util.Set;
-
-public abstract class SharedPreferenceHelper {
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    protected abstract SharedPreferences getPreferences();
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    public String get(int key, String defaultValue) {
-        return getPreferences().getString(getString(key), defaultValue);
-    }
-
-    // int, long, float value may be stored in String format (old versions)
-    public int get(int key, int defaultValue) {
-        try {
-            return getPreferences().getInt(getString(key), defaultValue);
-        } catch (ClassCastException ex) {
-            int ret = Integer.parseInt(get(key, String.valueOf(defaultValue)));
-            set(key, ret);
-            return ret;
-        }
-    }
-
-    public long get(int key, long defaultValue) {
-        try {
-            return getPreferences().getLong(getString(key), defaultValue);
-        } catch (ClassCastException ex) {
-            long ret = Long.parseLong(get(key, String.valueOf(defaultValue)));
-            set(key, ret);
-            return ret;
-        }
-    }
-
-    public float get(int key, float defaultValue) {
-        try {
-            return getPreferences().getFloat(getString(key), defaultValue);
-        } catch (ClassCastException ex) {
-            float ret = Float.parseFloat(get(key, String.valueOf(defaultValue)));
-            set(key, ret);
-            return ret;
-        }
-    }
-
-    public boolean get(int key, boolean defaultValue) {
-        return getPreferences().getBoolean(getString(key), defaultValue);
-    }
-
-    public Set<String> get(int key, Set<String> defaultValue) {
-        return getPreferences().getStringSet(getString(key), defaultValue);
-    }
-
-    public boolean set(int key, String value) {
-        return getPreferences().edit()
-                .putString(getString(key), value)
-                .commit();
-    }
-
-    public boolean set(int key, int value) {
-        return getPreferences().edit()
-                .putInt(getString(key), value)
-                .commit();
-    }
-
-    public boolean set(int key, long value) {
-        return getPreferences().edit()
-                .putLong(getString(key), value)
-                .commit();
-    }
-
-    public boolean set(int key, float value) {
-        return getPreferences().edit()
-                .putFloat(getString(key), value)
-                .commit();
-    }
-
-    public boolean set(int key, boolean value) {
-        return getPreferences().edit()
-                .putBoolean(getString(key), value)
-                .commit();
-    }
-
-    public boolean set(int key, Set<String> value) {
-        return getPreferences().edit()
-                .putStringSet(getString(key), value)
-                .commit();
-    }
-
-    private String getString(int resID) {
-        try {
-            return Application.getInstance().getString(resID);
-        } catch (Exception e) {
-            return null;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.kt b/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.kt
new file mode 100644
index 00000000..6702f1c3
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/preference/SharedPreferenceHelper.kt
@@ -0,0 +1,127 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.preference
+
+import android.content.SharedPreferences
+import net.lacolaco.smileessence.Application
+
+abstract class SharedPreferenceHelper {
+    // --------------------- GETTER / SETTER METHODS ---------------------
+
+    protected abstract val preferences: SharedPreferences
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    operator fun get(key: Int, defaultValue: String): String {
+        return preferences.getString(getString(key), defaultValue)
+    }
+
+    // int, long, float value may be stored in String format (old versions)
+    operator fun get(key: Int, defaultValue: Int): Int {
+        try {
+            return preferences.getInt(getString(key), defaultValue)
+        } catch (ex: ClassCastException) {
+            val ret = Integer.parseInt(get(key, defaultValue.toString()))
+            set(key, ret)
+            return ret
+        }
+
+    }
+
+    operator fun get(key: Int, defaultValue: Long): Long {
+        try {
+            return preferences.getLong(getString(key), defaultValue)
+        } catch (ex: ClassCastException) {
+            val ret = java.lang.Long.parseLong(get(key, defaultValue.toString()))
+            set(key, ret)
+            return ret
+        }
+
+    }
+
+    operator fun get(key: Int, defaultValue: Float): Float {
+        try {
+            return preferences.getFloat(getString(key), defaultValue)
+        } catch (ex: ClassCastException) {
+            val ret = java.lang.Float.parseFloat(get(key, defaultValue.toString()))
+            set(key, ret)
+            return ret
+        }
+
+    }
+
+    operator fun get(key: Int, defaultValue: Boolean): Boolean {
+        return preferences.getBoolean(getString(key), defaultValue)
+    }
+
+    operator fun get(key: Int, defaultValue: Set<String>): Set<String> {
+        return preferences.getStringSet(getString(key), defaultValue)
+    }
+
+    operator fun set(key: Int, value: String): Boolean {
+        return preferences.edit()
+                .putString(getString(key), value)
+                .commit()
+    }
+
+    operator fun set(key: Int, value: Int): Boolean {
+        return preferences.edit()
+                .putInt(getString(key), value)
+                .commit()
+    }
+
+    operator fun set(key: Int, value: Long): Boolean {
+        return preferences.edit()
+                .putLong(getString(key), value)
+                .commit()
+    }
+
+    operator fun set(key: Int, value: Float): Boolean {
+        return preferences.edit()
+                .putFloat(getString(key), value)
+                .commit()
+    }
+
+    operator fun set(key: Int, value: Boolean): Boolean {
+        return preferences.edit()
+                .putBoolean(getString(key), value)
+                .commit()
+    }
+
+    operator fun set(key: Int, value: Set<String>): Boolean {
+        return preferences.edit()
+                .putStringSet(getString(key), value)
+                .commit()
+    }
+
+    private fun getString(resID: Int): String? {
+        try {
+            return Application.getInstance().getString(resID)
+        } catch (e: Exception) {
+            return null
+        }
+
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.java b/app/src/main/java/net/lacolaco/smileessence/preference/UserPreferenceHelper.kt
index b2de5c21..41f7f019 100644
--- a/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.java
+++ b/app/src/main/java/net/lacolaco/smileessence/preference/UserPreferenceHelper.kt
@@ -22,35 +22,29 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.command;
+package net.lacolaco.smileessence.preference
 
-import net.lacolaco.smileessence.activity.MainActivity;
+import android.content.SharedPreferences
+import android.preference.PreferenceManager
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
 
-public class CommandAddHashtag extends Command {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private final String hashtag;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public CommandAddHashtag(MainActivity activity, String hashtag) {
-        super(activity);
-        this.hashtag = hashtag;
-    }
+class UserPreferenceHelper private constructor() : SharedPreferenceHelper() {
 
     // --------------------- GETTER / SETTER METHODS ---------------------
+    override val preferences: SharedPreferences
+        get() = PreferenceManager.getDefaultSharedPreferences(Application.getInstance())
 
-    @Override
-    public String getText() {
-        return "#" + hashtag;
-    }
+    // --------------------- HELPER METHODS ---------------------
+    val themeIndex: Int
+        get() = get(R.string.key_setting_theme, 0)
+
+    val textSize: Int
+        get() = get(R.string.key_setting_text_size, 10)
 
-    // -------------------------- OTHER METHODS --------------------------
+    companion object {
+        // --------------------------- CONSTRUCTORS ---------------------------
 
-    @Override
-    public boolean execute() {
-        getActivity().getWorld().getPostState().beginTransaction().appendText(" #" + hashtag).commit();
-        return true;
+        val instance = UserPreferenceHelper()
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/OAuthSession.java b/app/src/main/java/net/lacolaco/smileessence/twitter/OAuthSession.kt
index 160e710a..63a0c484 100644
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/OAuthSession.java
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/OAuthSession.kt
@@ -22,45 +22,51 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.twitter;
+package net.lacolaco.smileessence.twitter
 
-import net.lacolaco.smileessence.twitter.task.Accounts;
-import twitter4j.Twitter;
-import twitter4j.TwitterFactory;
-import twitter4j.auth.AccessToken;
-import twitter4j.auth.RequestToken;
+import net.lacolaco.smileessence.twitter.task.Accounts
+import twitter4j.Twitter
+import twitter4j.TwitterFactory
+import twitter4j.auth.AccessToken
+import twitter4j.auth.RequestToken
 
-public class OAuthSession {
-    public static final String KEY_TOKEN = "token";
-    public static final String KEY_TOKEN_SECRET = "tokenSecret";
-    public static final String KEY_SCREEN_NAME = "screenName";
-    public static final String KEY_USER_ID = "userID";
-    private RequestToken requestToken;
+class OAuthSession {
+    private var requestToken: RequestToken? = null
 
     // --------------------- GETTER / SETTER METHODS ---------------------
 
-    public String getAuthorizationURL() {
-        Twitter twitter = new TwitterFactory().getInstance();
-        Accounts.RequestTokenTask task = new Accounts.RequestTokenTask(twitter);
-        task.execute();
-        try {
-            requestToken = task.getImmediately();
-            return requestToken.getAuthorizationURL();
-        } catch (Exception e) {
-            return null;
+    val authorizationURL: String?
+        get() {
+            val twitter = TwitterFactory().instance
+            val task = Accounts.RequestTokenTask(twitter)
+            task.execute()
+            try {
+                requestToken = task.immediately
+                return requestToken!!.authorizationURL
+            } catch (e: Exception) {
+                return null
+            }
+
         }
-    }
 
     // -------------------------- OTHER METHODS --------------------------
 
-    public AccessToken getAccessToken(String pinCode) {
-        Twitter twitter = new TwitterFactory().getInstance();
-        Accounts.AccessTokenTask task = new Accounts.AccessTokenTask(twitter, requestToken, pinCode);
-        task.execute();
+    fun getAccessToken(pinCode: String): AccessToken? {
+        val twitter = TwitterFactory().instance
+        val task = Accounts.AccessTokenTask(twitter, requestToken!!, pinCode)
+        task.execute()
         try {
-            return task.getImmediately();
-        } catch (Exception e) {
-            return null;
+            return task.immediately
+        } catch (e: Exception) {
+            return null
         }
+
+    }
+
+    companion object {
+        val KEY_TOKEN = "token"
+        val KEY_TOKEN_SECRET = "tokenSecret"
+        val KEY_SCREEN_NAME = "screenName"
+        val KEY_USER_ID = "userID"
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.java b/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.java
deleted file mode 100644
index acfb44be..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.java
+++ /dev/null
@@ -1,235 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.twitter;
-
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.entity.Event;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.logging.Logger;
-import twitter4j.ConnectionLifeCycleListener;
-import twitter4j.Status;
-import twitter4j.StatusDeletionNotice;
-
-public class UserStreamListener implements twitter4j.UserStreamListener, ConnectionLifeCycleListener {
-    private final World world;
-    private boolean connected = false;
-
-    public UserStreamListener(World world) {
-        this.world = world;
-    }
-
-    public boolean isConnected() {
-        return connected;
-    }
-
-    @Override
-    public void onConnect() {
-        connected = true;
-        world.notify(R.string.notice_stream_connect);
-    }
-
-    @Override
-    public void onDisconnect() {
-        connected = false;
-        world.notify(R.string.notice_stream_disconnect);
-    }
-
-    @Override
-    public void onCleanUp() {
-    }
-
-    // --------------------- Interface StatusListener ---------------------
-
-    @Override
-    public void onStatus(Status status) {
-        User user = world.getAccount().getUser();
-        Tweet tweet = Tweet.fromTwitter(status, user.getId());
-        world.addTweet(tweet);
-        if (tweet.isRetweet()) {
-            if (tweet.getOriginalTweet().getUser().getId() == user.getId()) {
-                addToHistory(new Event(Event.EnumEvent.RETWEETED, tweet.getUser(), tweet));
-            }
-        } else if (tweet.getMentions().contains(user.getScreenName())) {
-            Event mentioned = new Event(Event.EnumEvent.MENTIONED, tweet.getUser(), tweet);
-            world.notify(mentioned.getFormattedString());
-        }
-    }
-
-    @Override
-    public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) {
-        // FIXME
-        // StatusFilter.getInstance().remove(StatusViewModel.class, statusDeletionNotice.getStatusId());
-        // Tweet.remove(statusDeletionNotice.getStatusId());
-    }
-
-    @Override
-    public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
-    }
-
-    @Override
-    public void onScrubGeo(long userId, long upToStatusId) {
-    }
-
-    @Override
-    public void onStallWarning(twitter4j.StallWarning warning) {
-    }
-
-    // --------------------- Interface StreamListener ---------------------
-
-    @Override
-    public void onException(Exception ex) {
-        Logger.error(ex.toString());
-    }
-
-    // --------------------- Interface UserStreamListener ---------------------
-
-    @Override
-    public void onDeletionNotice(long directMessageId, long userId) {
-        // FIXME
-        // StatusFilter.getInstance().remove(MessageViewModel.class, directMessageId);
-        // DirectMessage.remove(directMessageId);
-    }
-
-    @Override
-    public void onFriendList(long[] friendIds) {
-    }
-
-    @Override
-    public void onFavorite(twitter4j.User source, twitter4j.User target, Status favoritedStatus) {
-        Tweet tweet = Tweet.fromTwitter(favoritedStatus, world.getAccount().getUserId());
-        tweet.addFavoriter(source.getId());
-        if (User.fromTwitter(target) == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.FAVORITED, User.fromTwitter(source), tweet));
-        }
-    }
-
-    @Override
-    public void onUnfavorite(twitter4j.User source, twitter4j.User target, twitter4j.Status unfavoritedStatus) {
-        Tweet tweet = Tweet.fromTwitter(unfavoritedStatus, world.getAccount().getUserId());
-        tweet.removeFavoriter(source.getId());
-        if (User.fromTwitter(target) == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.UNFAVORITED, User.fromTwitter(source), tweet));
-        }
-    }
-
-    @Override
-    public void onFollow(twitter4j.User source, twitter4j.User followedUser) {
-        if (User.fromTwitter(followedUser) == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.FOLLOWED, User.fromTwitter(source)));
-        }
-    }
-
-    @Override
-    public void onUnfollow(twitter4j.User source, twitter4j.User unfollowedUser) {
-    }
-
-    @Override
-    public void onDirectMessage(twitter4j.DirectMessage directMessage) {
-        DirectMessage message = DirectMessage.fromTwitter(directMessage);
-        world.addDirectMessage(message);
-        if (message.getRecipient() == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.RECEIVE_MESSAGE, message.getSender()));
-        }
-    }
-
-    @Override
-    public void onUserListMemberAddition(twitter4j.User addedMember, twitter4j.User listOwner, twitter4j.UserList list) {
-    }
-
-    @Override
-    public void onUserListMemberDeletion(twitter4j.User deletedMember, twitter4j.User listOwner, twitter4j.UserList list) {
-    }
-
-    @Override
-    public void onUserListSubscription(twitter4j.User subscriber, twitter4j.User listOwner, twitter4j.UserList list) {
-        world.addListSubscription(list.getFullName());
-    }
-
-    @Override
-    public void onUserListUnsubscription(twitter4j.User subscriber, twitter4j.User listOwner, twitter4j.UserList list) {
-        world.removeListSubscription(list.getFullName());
-    }
-
-    @Override
-    public void onUserListCreation(twitter4j.User listOwner, twitter4j.UserList list) {
-        world.addListSubscription(list.getFullName());
-    }
-
-    @Override
-    public void onUserListUpdate(twitter4j.User listOwner, twitter4j.UserList list) {
-    }
-
-    @Override
-    public void onUserListDeletion(twitter4j.User listOwner, twitter4j.UserList list) {
-        world.removeListSubscription(list.getFullName());
-    }
-
-    @Override
-    public void onUserProfileUpdate(twitter4j.User updatedUser) {
-        User.fromTwitter(updatedUser);
-    }
-
-    @Override
-    public void onUserSuspension(long suspendedUser) {
-    }
-
-    @Override
-    public void onUserDeletion(long deletedUser) {
-    }
-
-    @Override
-    public void onBlock(twitter4j.User source, twitter4j.User blockedUser) {
-        if (User.fromTwitter(blockedUser) == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.BLOCKED, User.fromTwitter(source)));
-        }
-    }
-
-    @Override
-    public void onUnblock(twitter4j.User source, twitter4j.User unblockedUser) {
-        if (User.fromTwitter(unblockedUser) == world.getAccount().getUser()) {
-            addToHistory(new Event(Event.EnumEvent.UNBLOCKED, User.fromTwitter(source)));
-        }
-    }
-
-    @Override
-    public void onRetweetedRetweet(twitter4j.User source, twitter4j.User target, twitter4j.Status retweetedStatus) {
-    }
-
-    @Override
-    public void onFavoritedRetweet(twitter4j.User source, twitter4j.User target, twitter4j.Status favoritedRetweeet) {
-    }
-
-    @Override
-    public void onQuotedTweet(twitter4j.User source, twitter4j.User target, twitter4j.Status quotingTweet) {
-    }
-
-    private void addToHistory(Event mentioned) {
-        world.addEvent(mentioned);
-        world.notify(mentioned.getFormattedString());
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.kt
new file mode 100644
index 00000000..80a0c808
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/UserStreamListener.kt
@@ -0,0 +1,182 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.twitter
+
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.entity.Event
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.entity.User
+import net.lacolaco.smileessence.logging.Logger
+import twitter4j.ConnectionLifeCycleListener
+import twitter4j.Status
+import twitter4j.StatusDeletionNotice
+
+class UserStreamListener(private val world: World) : twitter4j.UserStreamListener, ConnectionLifeCycleListener {
+    var isConnected = false
+        private set
+
+    override fun onConnect() {
+        isConnected = true
+        world.notify(R.string.notice_stream_connect)
+    }
+
+    override fun onDisconnect() {
+        isConnected = false
+        world.notify(R.string.notice_stream_disconnect)
+    }
+
+    override fun onCleanUp() {}
+
+    // --------------------- Interface StatusListener ---------------------
+
+    override fun onStatus(status: Status) {
+        val user = world.account.user
+        val tweet = Tweet.fromTwitter(status, user.id)
+        world.addTweet(tweet)
+        if (tweet.isRetweet) {
+            if (tweet.originalTweet.user.id == user.id) {
+                addToHistory(Event(Event.EnumEvent.RETWEETED, tweet.user, tweet))
+            }
+        } else if (tweet.mentions.contains(user.screenName)) {
+            val mentioned = Event(Event.EnumEvent.MENTIONED, tweet.user, tweet)
+            world.notify(mentioned.formattedString)
+        }
+    }
+
+    override fun onDeletionNotice(statusDeletionNotice: StatusDeletionNotice) {
+        // FIXME
+        // StatusFilter.getInstance().remove(StatusViewModel.class, statusDeletionNotice.getStatusId());
+        // Tweet.remove(statusDeletionNotice.getStatusId());
+    }
+
+    override fun onTrackLimitationNotice(numberOfLimitedStatuses: Int) {}
+
+    override fun onScrubGeo(userId: Long, upToStatusId: Long) {}
+
+    override fun onStallWarning(warning: twitter4j.StallWarning) {}
+
+    // --------------------- Interface StreamListener ---------------------
+
+    override fun onException(ex: Exception) {
+        Logger.error(ex.toString())
+    }
+
+    // --------------------- Interface UserStreamListener ---------------------
+
+    override fun onDeletionNotice(directMessageId: Long, userId: Long) {
+        // FIXME
+        // StatusFilter.getInstance().remove(MessageViewModel.class, directMessageId);
+        // DirectMessage.remove(directMessageId);
+    }
+
+    override fun onFriendList(friendIds: LongArray) {}
+
+    override fun onFavorite(source: twitter4j.User, target: twitter4j.User, favoritedStatus: Status) {
+        val tweet = Tweet.fromTwitter(favoritedStatus, world.account.userId)
+        tweet.addFavoriter(source.id)
+        if (User.fromTwitter(target) === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.FAVORITED, User.fromTwitter(source), tweet))
+        }
+    }
+
+    override fun onUnfavorite(source: twitter4j.User, target: twitter4j.User, unfavoritedStatus: twitter4j.Status) {
+        val tweet = Tweet.fromTwitter(unfavoritedStatus, world.account.userId)
+        tweet.removeFavoriter(source.id)
+        if (User.fromTwitter(target) === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.UNFAVORITED, User.fromTwitter(source), tweet))
+        }
+    }
+
+    override fun onFollow(source: twitter4j.User, followedUser: twitter4j.User) {
+        if (User.fromTwitter(followedUser) === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.FOLLOWED, User.fromTwitter(source)))
+        }
+    }
+
+    override fun onUnfollow(source: twitter4j.User, unfollowedUser: twitter4j.User) {}
+
+    override fun onDirectMessage(directMessage: twitter4j.DirectMessage) {
+        val message = DirectMessage.fromTwitter(directMessage)
+        world.addDirectMessage(message)
+        if (message.recipient === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.RECEIVE_MESSAGE, message.sender))
+        }
+    }
+
+    override fun onUserListMemberAddition(addedMember: twitter4j.User, listOwner: twitter4j.User, list: twitter4j.UserList) {}
+
+    override fun onUserListMemberDeletion(deletedMember: twitter4j.User, listOwner: twitter4j.User, list: twitter4j.UserList) {}
+
+    override fun onUserListSubscription(subscriber: twitter4j.User, listOwner: twitter4j.User, list: twitter4j.UserList) {
+        world.addListSubscription(list.fullName)
+    }
+
+    override fun onUserListUnsubscription(subscriber: twitter4j.User, listOwner: twitter4j.User, list: twitter4j.UserList) {
+        world.removeListSubscription(list.fullName)
+    }
+
+    override fun onUserListCreation(listOwner: twitter4j.User, list: twitter4j.UserList) {
+        world.addListSubscription(list.fullName)
+    }
+
+    override fun onUserListUpdate(listOwner: twitter4j.User, list: twitter4j.UserList) {}
+
+    override fun onUserListDeletion(listOwner: twitter4j.User, list: twitter4j.UserList) {
+        world.removeListSubscription(list.fullName)
+    }
+
+    override fun onUserProfileUpdate(updatedUser: twitter4j.User) {
+        User.fromTwitter(updatedUser)
+    }
+
+    override fun onUserSuspension(suspendedUser: Long) {}
+
+    override fun onUserDeletion(deletedUser: Long) {}
+
+    override fun onBlock(source: twitter4j.User, blockedUser: twitter4j.User) {
+        if (User.fromTwitter(blockedUser) === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.BLOCKED, User.fromTwitter(source)))
+        }
+    }
+
+    override fun onUnblock(source: twitter4j.User, unblockedUser: twitter4j.User) {
+        if (User.fromTwitter(unblockedUser) === world.account.user) {
+            addToHistory(Event(Event.EnumEvent.UNBLOCKED, User.fromTwitter(source)))
+        }
+    }
+
+    override fun onRetweetedRetweet(source: twitter4j.User, target: twitter4j.User, retweetedStatus: twitter4j.Status) {}
+
+    override fun onFavoritedRetweet(source: twitter4j.User, target: twitter4j.User, favoritedRetweeet: twitter4j.Status) {}
+
+    override fun onQuotedTweet(source: twitter4j.User, target: twitter4j.User, quotingTweet: twitter4j.Status) {}
+
+    private fun addToHistory(mentioned: Event) {
+        world.addEvent(mentioned)
+        world.notify(mentioned.formattedString)
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.java
deleted file mode 100644
index 7842e349..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import twitter4j.IDs;
-import twitter4j.Twitter;
-import twitter4j.TwitterException;
-import twitter4j.auth.AccessToken;
-import twitter4j.auth.RequestToken;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Accounts {
-    public static class AccessTokenTask extends BackgroundTask<AccessToken, Void> {
-        private final Twitter twitter;
-        private final RequestToken requestToken;
-        private final String pinCode;
-
-        public AccessTokenTask(Twitter twitter, RequestToken requestToken, String pinCode) {
-            this.twitter = twitter;
-            this.requestToken = requestToken;
-            this.pinCode = pinCode;
-        }
-
-        @Override
-        protected AccessToken doInBackground() throws TwitterException {
-            return twitter.getOAuthAccessToken(requestToken, pinCode);
-        }
-    }
-
-    public static class RequestTokenTask extends BackgroundTask<RequestToken, Void> {
-        private final Twitter twitter;
-
-        public RequestTokenTask(Twitter twitter) {
-            this.twitter = twitter;
-        }
-
-        @Override
-        protected RequestToken doInBackground() throws TwitterException {
-            return twitter.getOAuthRequestToken("oob");
-        }
-    }
-
-    public static class BlockIDsTask extends BackgroundTask<List<Long>, Void> {
-        private final Account account;
-
-        public BlockIDsTask(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<Long> doInBackground() throws TwitterException {
-            List<Long> idList = new ArrayList<>();
-            long cursor = -1;
-
-            while (cursor != 0) {
-                IDs blocksIDs = account.getTwitter().getBlocksIDs(cursor);
-                cursor = blocksIDs.getNextCursor();
-                for (long id : blocksIDs.getIDs()) {
-                    idList.add(id);
-                }
-            }
-
-            return idList;
-        }
-    }
-
-    public static class MutesIDsTask extends BackgroundTask<List<Long>, Void> {
-        private final Account account;
-
-        public MutesIDsTask(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<Long> doInBackground() throws TwitterException {
-            List<Long> idList = new ArrayList<>();
-            long cursor = -1;
-            while (cursor != 0) {
-                IDs mutesIDs = account.getTwitter().getMutesIDs(cursor);
-                cursor = mutesIDs.getNextCursor();
-                for (long id : mutesIDs.getIDs()) {
-                    idList.add(id);
-                }
-            }
-            return idList;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.kt
new file mode 100644
index 00000000..22a90374
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Accounts.kt
@@ -0,0 +1,65 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.IDs
+import twitter4j.Twitter
+import twitter4j.TwitterException
+import twitter4j.auth.AccessToken
+import twitter4j.auth.RequestToken
+
+import java.util.ArrayList
+
+class Accounts {
+    class AccessTokenTask(private val twitter: Twitter, private val requestToken: RequestToken, private val pinCode: String) : BackgroundTask<AccessToken, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): AccessToken {
+            return twitter.getOAuthAccessToken(requestToken, pinCode)
+        }
+    }
+
+    class RequestTokenTask(private val twitter: Twitter) : BackgroundTask<RequestToken, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): RequestToken {
+            return twitter.getOAuthRequestToken("oob")
+        }
+    }
+
+    class BlockIDsTask(private val account: Account) : BackgroundTask<List<Long>, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Long> {
+            val idList = ArrayList<Long>()
+            var cursor: Long = -1
+
+            while (cursor != 0L) {
+                val blocksIDs = account.twitter.getBlocksIDs(cursor)
+                cursor = blocksIDs.nextCursor
+                for (id in blocksIDs.iDs) {
+                    idList.add(id)
+                }
+            }
+
+            return idList
+        }
+    }
+
+    class MutesIDsTask(private val account: Account) : BackgroundTask<List<Long>, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Long> {
+            val idList = ArrayList<Long>()
+            var cursor: Long = -1
+            while (cursor != 0L) {
+                val mutesIDs = account.twitter.getMutesIDs(cursor)
+                cursor = mutesIDs.nextCursor
+                for (id in mutesIDs.iDs) {
+                    idList.add(id)
+                }
+            }
+            return idList
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.java
deleted file mode 100644
index ff13a07c..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import twitter4j.TwitterException;
-
-import java.util.List;
-
-public class Messages {
-    public static class CreateTask extends BackgroundTask<DirectMessage, Void> {
-        private final Account account;
-        private final long userID;
-        private final String text;
-
-        public CreateTask(Account account, long userID, String text) {
-            this.account = account;
-            this.userID = userID;
-            this.text = text;
-        }
-
-        @Override
-        protected DirectMessage doInBackground() throws TwitterException {
-            return DirectMessage.fromTwitter(account.getTwitter().directMessages().sendDirectMessage(userID, text));
-        }
-    }
-
-    public static class DestroyTask extends BackgroundTask<DirectMessage, Void> {
-        private final Account account;
-        private final long messageID;
-
-        public DestroyTask(Account account, long messageID) {
-            this.account = account;
-            this.messageID = messageID;
-        }
-
-        @Override
-        protected DirectMessage doInBackground() throws TwitterException {
-            return DirectMessage.fromTwitter(account.getTwitter().directMessages().destroyDirectMessage(messageID));
-        }
-    }
-
-    public static class GetAllReceived extends TimelineTask<DirectMessage> {
-        private final Account account;
-
-        public GetAllReceived(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<DirectMessage> doInBackground() throws TwitterException {
-            return DirectMessage.fromTwitter(account.getTwitter().directMessages().getDirectMessages(getPaging()));
-        }
-    }
-
-    public static class GetAllSent extends TimelineTask<DirectMessage> {
-        private final Account account;
-
-        public GetAllSent(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<DirectMessage> doInBackground() throws TwitterException {
-            return DirectMessage.fromTwitter(account.getTwitter().directMessages().getSentDirectMessages(getPaging()));
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.kt
new file mode 100644
index 00000000..b5553c32
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Messages.kt
@@ -0,0 +1,40 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.TwitterException
+
+class Messages {
+    class CreateTask(private val account: Account, private val userID: Long, private val text: String) : BackgroundTask<DirectMessage, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): DirectMessage {
+            return DirectMessage.fromTwitter(account.twitter.directMessages().sendDirectMessage(userID, text))
+        }
+    }
+
+    class DestroyTask(private val account: Account, private val messageID: Long) : BackgroundTask<DirectMessage, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): DirectMessage {
+            return DirectMessage.fromTwitter(account.twitter.directMessages().destroyDirectMessage(messageID))
+        }
+    }
+
+    class GetAllReceived(private val account: Account) : TimelineTask<DirectMessage>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<DirectMessage> {
+            return DirectMessage.fromTwitter(account.twitter.directMessages().getDirectMessages(paging))
+        }
+    }
+
+    class GetAllSent(private val account: Account) : TimelineTask<DirectMessage>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<DirectMessage> {
+            return DirectMessage.fromTwitter(account.twitter.directMessages().getSentDirectMessages(paging))
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.java
deleted file mode 100644
index 91f6fbcc..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.java
+++ /dev/null
@@ -1,80 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.SavedSearch;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import net.lacolaco.smileessence.util.ListUtils;
-import twitter4j.Query;
-import twitter4j.TwitterException;
-
-import java.util.List;
-
-public class Searches {
-    public static class CreateSavedSearchTask extends BackgroundTask<SavedSearch, Void> {
-        private final Account account;
-        private final String query;
-
-        public CreateSavedSearchTask(Account account, String query) {
-            this.account = account;
-            this.query = query;
-        }
-
-        @Override
-        protected SavedSearch doInBackground() throws Exception {
-            return SavedSearch.fromTwitter(account.getTwitter().savedSearches().createSavedSearch(query));
-        }
-    }
-
-    public static class DestroySavedSearchTask extends BackgroundTask<Void, Void> {
-        private final Account account;
-        private final long id;
-
-        public DestroySavedSearchTask(Account account, long id) {
-            this.account = account;
-            this.id = id;
-        }
-
-        @Override
-        protected Void doInBackground() throws Exception {
-            account.getTwitter().savedSearches().destroySavedSearch(id);
-            return null;
-        }
-    }
-
-    public static class GetAllSavedSearchesTask extends BackgroundTask<List<SavedSearch>, Void> {
-        private final Account account;
-
-        public GetAllSavedSearchesTask(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<SavedSearch> doInBackground() throws Exception {
-            return ListUtils.map(account.getTwitter().savedSearches().getSavedSearches(), SavedSearch::fromTwitter);
-        }
-    }
-
-    // TODO: List<Tweet> is not good here
-    public static class SearchTask extends BackgroundTask<List<Tweet>, Void> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-        private final Query query;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public SearchTask(Account account, Query query) {
-            this.account = account;
-            this.query = query;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected List<Tweet> doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().search(query).getTweets(), account.getUserId());
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.kt
new file mode 100644
index 00000000..9ea1792b
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Searches.kt
@@ -0,0 +1,51 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.SavedSearch
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.Query
+import twitter4j.TwitterException
+
+class Searches {
+    class CreateSavedSearchTask(private val account: Account, private val query: String) : BackgroundTask<SavedSearch, Void>() {
+
+        @Throws(Exception::class)
+        override fun doInBackground(): SavedSearch {
+            return SavedSearch.fromTwitter(account.twitter.savedSearches().createSavedSearch(query))
+        }
+    }
+
+    class DestroySavedSearchTask(private val account: Account, private val id: Long) : BackgroundTask<Unit, Void>() {
+
+        @Throws(Exception::class)
+        override fun doInBackground() {
+            account.twitter.savedSearches().destroySavedSearch(id)
+        }
+    }
+
+    class GetAllSavedSearchesTask(private val account: Account) : BackgroundTask<List<SavedSearch>, Void>() {
+
+        @Throws(Exception::class)
+        override fun doInBackground(): List<SavedSearch> {
+            return account.twitter.savedSearches().savedSearches.map { SavedSearch.fromTwitter(it)}
+        }
+    }
+
+    // TODO: List<Tweet> is not good here
+    class SearchTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account, private val query: Query) : BackgroundTask<List<Tweet>, Void>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Tweet> {
+            return Tweet.fromTwitter(account.twitter.search(query).tweets, account.userId)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/TimelineTask.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/TimelineTask.kt
index 1025d3e9..d6b2c054 100644
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/TimelineTask.java
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/TimelineTask.kt
@@ -22,36 +22,30 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.twitter.task;
+package net.lacolaco.smileessence.twitter.task
 
-import net.lacolaco.smileessence.util.BackgroundTask;
-import twitter4j.Paging;
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.Paging
 
-import java.util.List;
+abstract class TimelineTask<T> : BackgroundTask<List<T>, Void>() {
+    protected val paging = Paging()
 
-public abstract class TimelineTask<T> extends BackgroundTask<List<T>, Void> {
-    private Paging paging = new Paging();
-
-    public TimelineTask<T> setCount(int count) {
-        paging.setCount(count);
-        return this;
+    fun setCount(count: Int): TimelineTask<T> {
+        paging.count = count
+        return this
     }
 
-    public TimelineTask<T> setMaxId(long maxId) {
+    fun setMaxId(maxId: Long): TimelineTask<T> {
         if (maxId > 0) {
-            paging.setMaxId(maxId);
+            paging.maxId = maxId
         }
-        return this;
+        return this
     }
 
-    public TimelineTask<T> setSinceId(long sinceId) {
+    fun setSinceId(sinceId: Long): TimelineTask<T> {
         if (sinceId > 0) {
-            paging.setSinceId(sinceId);
+            paging.sinceId = sinceId
         }
-        return this;
-    }
-
-    protected Paging getPaging() {
-        return paging;
+        return this
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.java
deleted file mode 100644
index ae1aa0ea..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.java
+++ /dev/null
@@ -1,94 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.Tweet;
-import twitter4j.TwitterException;
-
-import java.util.List;
-
-public class Timelines {
-    public static class HomeTimelineTask extends TimelineTask<Tweet> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public HomeTimelineTask(Account account) {
-            this.account = account;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected List<Tweet> doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().timelines().getHomeTimeline(getPaging()), account.getUserId());
-        }
-    }
-
-    public static class MentionsTimelineTask extends TimelineTask<Tweet> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public MentionsTimelineTask(Account account) {
-            this.account = account;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected List<Tweet> doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().timelines().getMentionsTimeline(getPaging()), account.getUserId());
-        }
-    }
-
-    public static class UserTimelineTask extends TimelineTask<Tweet> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final long userID;
-        private final Account account;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public UserTimelineTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected List<Tweet> doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().timelines().getUserTimeline(userID, getPaging()), account.getUserId());
-        }
-    }
-
-    public static class UserListStatusesTask extends TimelineTask<Tweet> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-        private final String listFullName;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public UserListStatusesTask(Account account, String listFullName) {
-            this.account = account;
-            this.listFullName = listFullName;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected List<Tweet> doInBackground() throws TwitterException {
-            String[] strings = listFullName.split("/");
-            return Tweet.fromTwitter(account.getTwitter().list().getUserListStatuses(strings[0], strings[1], getPaging()), account.getUserId());
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.kt
new file mode 100644
index 00000000..6893319c
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Timelines.kt
@@ -0,0 +1,72 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.Tweet
+import twitter4j.TwitterException
+
+class Timelines {
+    class HomeTimelineTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account) : TimelineTask<Tweet>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Tweet> {
+            return Tweet.fromTwitter(account.twitter.timelines().getHomeTimeline(paging), account.userId)
+        }
+    }
+
+    class MentionsTimelineTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account) : TimelineTask<Tweet>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Tweet> {
+            return Tweet.fromTwitter(account.twitter.timelines().getMentionsTimeline(paging), account.userId)
+        }
+    }
+
+    class UserTimelineTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (private val account: Account,
+            // ------------------------------ FIELDS ------------------------------
+
+     private val userID: Long) : TimelineTask<Tweet>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Tweet> {
+            return Tweet.fromTwitter(account.twitter.timelines().getUserTimeline(userID, paging), account.userId)
+        }
+    }
+
+    class UserListStatusesTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account, private val listFullName: String) : TimelineTask<Tweet>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<Tweet> {
+            val strings = listFullName.split("/".toRegex()).dropLastWhile({ it.isEmpty() }).toTypedArray()
+            return Tweet.fromTwitter(account.twitter.list().getUserListStatuses(strings[0], strings[1], paging), account.userId)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.java
deleted file mode 100644
index f201492e..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.java
+++ /dev/null
@@ -1,74 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import twitter4j.TwitterException;
-
-public class TweetReactions {
-    public static class RetweetTask extends BackgroundTask<Tweet, Void> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-        private final long statusID;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public RetweetTask(Account account, long statusID) {
-            this.account = account;
-            this.statusID = statusID;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().tweets().retweetStatus(statusID), account.getUserId());
-        }
-    }
-
-    public static class FavoriteTask extends BackgroundTask<Tweet, Void> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-        private final long statusID;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public FavoriteTask(Account account, long statusID) {
-            this.account = account;
-            this.statusID = statusID;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().favorites().createFavorite(statusID), account.getUserId());
-        }
-    }
-
-    public static class UnfavoriteTask extends BackgroundTask<Tweet, Void> {
-
-        // ------------------------------ FIELDS ------------------------------
-
-        private final Account account;
-        private final long statusID;
-
-        // --------------------------- CONSTRUCTORS ---------------------------
-
-        public UnfavoriteTask(Account account, long statusID) {
-            this.account = account;
-            this.statusID = statusID;
-        }
-
-        // ------------------------ OVERRIDE METHODS ------------------------
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().favorites().destroyFavorite(statusID), account.getUserId());
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.kt
new file mode 100644
index 00000000..bffcd832
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/TweetReactions.kt
@@ -0,0 +1,56 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.TwitterException
+
+class TweetReactions {
+    class RetweetTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account, private val statusID: Long) : BackgroundTask<Tweet, Void>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+            return Tweet.fromTwitter(account.twitter.tweets().retweetStatus(statusID), account.userId)
+        }
+    }
+
+    class FavoriteTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account, private val statusID: Long) : BackgroundTask<Tweet, Void>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+            return Tweet.fromTwitter(account.twitter.favorites().createFavorite(statusID), account.userId)
+        }
+    }
+
+    class UnfavoriteTask
+    // --------------------------- CONSTRUCTORS ---------------------------
+
+    (
+            // ------------------------------ FIELDS ------------------------------
+
+            private val account: Account, private val statusID: Long) : BackgroundTask<Tweet, Void>() {
+
+        // ------------------------ OVERRIDE METHODS ------------------------
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+            return Tweet.fromTwitter(account.twitter.favorites().destroyFavorite(statusID), account.userId)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.java
deleted file mode 100644
index dcad94dc..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.java
+++ /dev/null
@@ -1,153 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.os.Environment;
-import android.text.TextUtils;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import twitter4j.StatusUpdate;
-import twitter4j.TwitterException;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-
-public class Tweets {
-    public static class GetTask extends BackgroundTask<Tweet, Void> {
-        private final Account account;
-        private final long id;
-
-        public GetTask(Account account, long id) {
-            this.account = account;
-            this.id = id;
-        }
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            return Tweet.fromTwitter(account.getTwitter().tweets().showStatus(id), account.getUserId());
-        }
-    }
-
-    public static class CreateTask extends BackgroundTask<Tweet, Void> {
-        private static final int MEDIA_SIZE_LIMIT = 5 * 1024 * 1024;
-        private final Account account;
-        private final StatusUpdate update;
-        private final String mediaPath;
-        private String tempFilePath;
-        private boolean resizeFlag;
-
-        public CreateTask(Account account, StatusUpdate update, String mediaPath, boolean resize) {
-            this.account = account;
-            this.update = update;
-            this.mediaPath = mediaPath;
-            resizeFlag = resize;
-        }
-
-        private File getMediaFile() {
-            File file = new File(mediaPath);
-            if (file.length() >= MEDIA_SIZE_LIMIT && resizeFlag) {
-                BitmapFactory.Options opt = new BitmapFactory.Options();
-                opt.inJustDecodeBounds = true; //decoder is not return bitmap but set option
-                BitmapFactory.decodeFile(mediaPath, opt);
-                tempFilePath = Environment.getExternalStorageDirectory() + "/temp.jpg";
-                File compressedFile = new File(tempFilePath);
-                FileOutputStream fos = null;
-                try {
-                    fos = new FileOutputStream(compressedFile);
-                    float ratio = (float) file.length() / (float) MEDIA_SIZE_LIMIT;
-                    BitmapFactory.Options resizeOpt = new BitmapFactory.Options();
-                    resizeOpt.inPurgeable = true;
-                    resizeOpt.inSampleSize = (int) Math.ceil(ratio);
-                    Bitmap bitmap = BitmapFactory.decodeFile(mediaPath, resizeOpt);
-                    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
-                    bitmap.recycle();
-                    return compressedFile;
-                } catch (Exception e) {
-                    e.printStackTrace();
-                    Logger.error(e);
-                } finally {
-                    try {
-                        if (fos != null) fos.close();
-                    } catch (IOException e) {
-                        e.printStackTrace();
-                        Logger.error(e);
-                    }
-                }
-            }
-            return file;
-        }
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            try {
-                if (!TextUtils.isEmpty(mediaPath)) {
-                    File mediaFile = getMediaFile();
-                    if (mediaFile.exists()) {
-                        update.setMedia(mediaFile);
-                    }
-                }
-                return Tweet.fromTwitter(account.getTwitter().tweets().updateStatus(update), account.getUserId());
-            } finally {
-                if (tempFilePath != null) {
-                    new File(tempFilePath).delete();
-                }
-            }
-        }
-    }
-
-    public static class DestroyTask extends BackgroundTask<Tweet, Void> {
-        private final Account account;
-        private final long statusID;
-
-        public DestroyTask(Account account, long statusID) {
-            this.account = account;
-            this.statusID = statusID;
-        }
-
-        @Override
-        protected Tweet doInBackground() throws TwitterException {
-            Tweet t = Tweet.fromTwitter(account.getTwitter().tweets().destroyStatus(statusID), account.getUserId());
-            // FIXME: Tweet.remove(t.getId());
-            return t;
-        }
-    }
-
-    public static class GetTalkTask extends BackgroundTask<List<Tweet>, Tweet> {
-        private final Account account;
-        private final long statusId;
-
-        public GetTalkTask(Account account, long statusId) {
-            this.account = account;
-            this.statusId = statusId;
-        }
-
-        @Override
-        protected List<Tweet> doInBackground() {
-            ArrayList<Tweet> list = new ArrayList<>();
-            long id = statusId;
-            while (id != -1) {
-                Tweet tweet = Tweet.fetch(id);
-                if (tweet == null) {
-                    try {
-                        tweet = Tweet.fromTwitter(account.getTwitter().showStatus(id), account.getUserId());
-                    } catch (TwitterException ignored) {
-                    }
-                }
-
-                if (tweet == null) {
-                    break;
-                } else {
-                    list.add(tweet);
-                    progress(tweet);
-                    id = tweet.getInReplyToStatusId();
-                }
-            }
-            return list;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.kt
new file mode 100644
index 00000000..1af42d20
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Tweets.kt
@@ -0,0 +1,125 @@
+package net.lacolaco.smileessence.twitter.task
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.os.Environment
+import android.text.TextUtils
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.StatusUpdate
+import twitter4j.TwitterException
+
+import java.io.File
+import java.io.FileOutputStream
+import java.io.IOException
+import java.util.ArrayList
+
+class Tweets {
+    class GetTask(private val account: Account, private val id: Long) : BackgroundTask<Tweet, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+            return Tweet.fromTwitter(account.twitter.tweets().showStatus(id), account.userId)
+        }
+    }
+
+    class CreateTask(private val account: Account, private val update: StatusUpdate, private val mediaPath: String, private val resizeFlag: Boolean) : BackgroundTask<Tweet, Void>() {
+        private var tempFilePath: String? = null
+
+        private //decoder is not return bitmap but set option
+        val mediaFile: File
+            get() {
+                val file = File(mediaPath)
+                if (file.length() >= MEDIA_SIZE_LIMIT && resizeFlag) {
+                    val opt = BitmapFactory.Options()
+                    opt.inJustDecodeBounds = true
+                    BitmapFactory.decodeFile(mediaPath, opt)
+                    tempFilePath = Environment.getExternalStorageDirectory().toString() + "/temp.jpg"
+                    val compressedFile = File(tempFilePath)
+                    var fos: FileOutputStream? = null
+                    try {
+                        fos = FileOutputStream(compressedFile)
+                        val ratio = file.length().toFloat() / MEDIA_SIZE_LIMIT.toFloat()
+                        val resizeOpt = BitmapFactory.Options()
+                        resizeOpt.inPurgeable = true
+                        resizeOpt.inSampleSize = Math.ceil(ratio.toDouble()).toInt()
+                        val bitmap = BitmapFactory.decodeFile(mediaPath, resizeOpt)
+                        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos)
+                        bitmap.recycle()
+                        return compressedFile
+                    } catch (e: Exception) {
+                        e.printStackTrace()
+                        Logger.error(e)
+                    } finally {
+                        try {
+                            if (fos != null) fos.close()
+                        } catch (e: IOException) {
+                            e.printStackTrace()
+                            Logger.error(e)
+                        }
+
+                    }
+                }
+                return file
+            }
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+            try {
+                if (!TextUtils.isEmpty(mediaPath)) {
+                    val mediaFile = mediaFile
+                    if (mediaFile.exists()) {
+                        update.setMedia(mediaFile)
+                    }
+                }
+                return Tweet.fromTwitter(account.twitter.tweets().updateStatus(update), account.userId)
+            } finally {
+                if (tempFilePath != null) {
+                    File(tempFilePath).delete()
+                }
+            }
+        }
+
+        companion object {
+            private val MEDIA_SIZE_LIMIT = 5 * 1024 * 1024
+        }
+    }
+
+    class DestroyTask(private val account: Account, private val statusID: Long) : BackgroundTask<Tweet, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Tweet {
+// FIXME: Tweet.remove(t.getId());
+            return Tweet.fromTwitter(account.twitter.tweets().destroyStatus(statusID), account.userId)
+        }
+    }
+
+    class GetTalkTask(private val account: Account, private val statusId: Long) : BackgroundTask<List<Tweet>, Tweet>() {
+
+        override fun doInBackground(): List<Tweet> {
+            val list = ArrayList<Tweet>()
+            var id = statusId
+            while (id != -1L) {
+                var tweet = Tweet.fetch(id)
+                if (tweet == null) {
+                    try {
+                        tweet = Tweet.fromTwitter(account.twitter.showStatus(id), account.userId)
+                    } catch (ignored: TwitterException) {
+                    }
+
+                }
+
+                if (tweet == null) {
+                    break
+                } else {
+                    list.add(tweet)
+                    progress(tweet)
+                    id = tweet.inReplyToStatusId
+                }
+            }
+            return list
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.java b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.java
deleted file mode 100644
index 60b62841..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.java
+++ /dev/null
@@ -1,143 +0,0 @@
-package net.lacolaco.smileessence.twitter.task;
-
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.util.BackgroundTask;
-import net.lacolaco.smileessence.util.ListUtils;
-import twitter4j.Relationship;
-import twitter4j.TwitterException;
-import twitter4j.UserList;
-
-import java.util.List;
-
-public class Users {
-    public static class GetTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-        private final String screenName;
-
-        public GetTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-            this.screenName = null;
-        }
-
-        public GetTask(Account account, String screenName) {
-            this.account = account;
-            this.screenName = screenName;
-            this.userID = -1;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            if (screenName != null) {
-                return User.fromTwitter(account.getTwitter().users().showUser(screenName));
-            } else {
-                return User.fromTwitter(account.getTwitter().users().showUser(userID));
-            }
-        }
-    }
-
-    public static class GetManyTask extends BackgroundTask<List<String>, Void> {
-        private final Account account;
-
-        public GetManyTask(Account account) {
-            this.account = account;
-        }
-
-        @Override
-        protected List<String> doInBackground() throws TwitterException {
-            return ListUtils.map(account.getTwitter().list().getUserLists(account.getUserId()), UserList::getFullName);
-        }
-    }
-
-    public static class FollowTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-
-        public FollowTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            return User.fromTwitter(account.getTwitter().friendsFollowers().createFriendship(userID));
-        }
-    }
-
-    public static class UnfollowTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-
-        public UnfollowTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            return User.fromTwitter(account.getTwitter().friendsFollowers().destroyFriendship(userID));
-        }
-    }
-
-    public static class BlockTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-
-        public BlockTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            return User.fromTwitter(account.getTwitter().users().createBlock(userID));
-        }
-    }
-
-    public static class ReportForSpamTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-
-        public ReportForSpamTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            return User.fromTwitter(account.getTwitter().spamReporting().reportSpam(userID));
-        }
-    }
-
-    public static class UnblockTask extends BackgroundTask<User, Void> {
-        private final Account account;
-        private final long userID;
-
-        public UnblockTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected User doInBackground() throws TwitterException {
-            return User.fromTwitter(account.getTwitter().users().destroyBlock(userID));
-        }
-    }
-
-    public static class ShowFriendshipTask extends BackgroundTask<Relationship, Void> {
-        private final Account account;
-        private final long userID;
-
-        public ShowFriendshipTask(Account account, long userID) {
-            this.account = account;
-            this.userID = userID;
-        }
-
-        @Override
-        protected Relationship doInBackground() throws TwitterException {
-            return account.getTwitter().friendsFollowers().showFriendship(account.getTwitter().getId(), userID);
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.kt b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.kt
new file mode 100644
index 00000000..c435b560
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/twitter/task/Users.kt
@@ -0,0 +1,92 @@
+package net.lacolaco.smileessence.twitter.task
+
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.User
+import net.lacolaco.smileessence.util.BackgroundTask
+import twitter4j.Relationship
+import twitter4j.TwitterException
+
+class Users {
+    class GetTask : BackgroundTask<User, Void> {
+        private val account: Account
+        private val userID: Long
+        private val screenName: String?
+
+        constructor(account: Account, userID: Long) {
+            this.account = account
+            this.userID = userID
+            this.screenName = null
+        }
+
+        constructor(account: Account, screenName: String) {
+            this.account = account
+            this.screenName = screenName
+            this.userID = -1
+        }
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return if (screenName != null) {
+                User.fromTwitter(account.twitter.users().showUser(screenName))
+            } else {
+                User.fromTwitter(account.twitter.users().showUser(userID))
+            }
+        }
+    }
+
+    class GetManyTask(private val account: Account) : BackgroundTask<List<String>, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): List<String> {
+            return account.twitter.list().getUserLists(account.userId).map { it.fullName }
+        }
+    }
+
+    class FollowTask(private val account: Account, private val userID: Long) : BackgroundTask<User, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return User.fromTwitter(account.twitter.friendsFollowers().createFriendship(userID))
+        }
+    }
+
+    class UnfollowTask(private val account: Account, private val userID: Long) : BackgroundTask<User, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return User.fromTwitter(account.twitter.friendsFollowers().destroyFriendship(userID))
+        }
+    }
+
+    class BlockTask(private val account: Account, private val userID: Long) : BackgroundTask<User, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return User.fromTwitter(account.twitter.users().createBlock(userID))
+        }
+    }
+
+    class ReportForSpamTask(private val account: Account, private val userID: Long) : BackgroundTask<User, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return User.fromTwitter(account.twitter.spamReporting().reportSpam(userID))
+        }
+    }
+
+    class UnblockTask(private val account: Account, private val userID: Long) : BackgroundTask<User, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): User {
+            return User.fromTwitter(account.twitter.users().destroyBlock(userID))
+        }
+    }
+
+    class ShowFriendshipTask(private val account: Account, private val userID: Long) : BackgroundTask<Relationship, Void>() {
+
+        @Throws(TwitterException::class)
+        override fun doInBackground(): Relationship {
+            return account.twitter.friendsFollowers().showFriendship(account.twitter.id, userID)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.java b/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.java
deleted file mode 100644
index b6d985e2..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.java
+++ /dev/null
@@ -1,111 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-import android.os.AsyncTask;
-import net.lacolaco.smileessence.logging.Logger;
-
-public abstract class BackgroundTask<Result, Progress> {
-    private final InnerAsyncTask task;
-    private Consumer<Result> then;
-    private Consumer<Progress> progress;
-    private Consumer<Exception> fail;
-    private Runnable finish;
-    private Exception exception;
-
-    public BackgroundTask() {
-        this.task = new InnerAsyncTask();
-    }
-
-    public BackgroundTask<Result, Progress> onDone(Consumer<Result> cb) {
-        this.then = cb;
-        return this;
-    }
-
-    public BackgroundTask<Result, Progress> onProgress(Consumer<Progress> cb) {
-        this.progress = cb;
-        return this;
-    }
-
-    public BackgroundTask<Result, Progress> onFail(Consumer<Exception> cb) {
-        this.fail = cb;
-        return this;
-    }
-
-    public BackgroundTask<Result, Progress> onFinish(Runnable cb) {
-        this.finish = cb;
-        return this;
-    }
-
-    public BackgroundTask<Result, Progress> onDoneUI(Consumer<Result> cb) {
-        return onDone(r -> new UIHandler().post(() -> cb.accept(r)));
-    }
-
-    public BackgroundTask<Result, Progress> onProgressUI(Consumer<Progress> cb) {
-        return onProgress(p -> new UIHandler().post(() -> cb.accept(p)));
-    }
-
-    public BackgroundTask<Result, Progress> onFailUI(Consumer<Exception> cb) {
-        return onFail(e -> new UIHandler().post(() -> cb.accept(e)));
-    }
-
-    public BackgroundTask<Result, Progress> onFinishUI(Runnable cb) {
-        return onFinish(() -> new UIHandler().post(cb));
-    }
-
-    public boolean cancel() {
-        return task.cancel(true);
-    }
-
-    public final BackgroundTask<Result, Progress> execute() {
-        task.execute();
-        return this;
-    }
-
-    public final Result getImmediately() throws Exception {
-        Result result = task.get();
-        if (exception == null) {
-            return result;
-        } else {
-            throw exception;
-        }
-    }
-
-    protected void fail(Exception ex) {
-        exception = ex;
-        ex.printStackTrace();
-        Logger.error(ex);
-
-        if (!task.isCancelled() && fail != null) {
-            fail.accept(ex);
-        }
-    }
-
-    protected void progress(Progress value) {
-        if (!task.isCancelled() && exception == null && progress != null) {
-            progress.accept(value);
-        }
-    }
-
-    protected abstract Result doInBackground() throws Exception;
-
-    private class InnerAsyncTask extends AsyncTask<Void, Progress, Result> {
-        @Override
-        protected final void onPostExecute(Result result) {
-            if (!isCancelled() && exception == null && then != null) {
-                then.accept(result);
-            }
-            if (finish != null) {
-                finish.run();
-            }
-        }
-
-        @Override
-        protected Result doInBackground(Void... params) {
-            try {
-                return BackgroundTask.this.doInBackground();
-            } catch (Exception ex) {
-                fail(ex);
-                return null;
-            }
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.kt b/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.kt
new file mode 100644
index 00000000..7b9e188a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/BackgroundTask.kt
@@ -0,0 +1,113 @@
+package net.lacolaco.smileessence.util
+
+import android.os.AsyncTask
+import net.lacolaco.smileessence.logging.Logger
+
+abstract class BackgroundTask<Result, Progress> {
+    private val task: InnerAsyncTask
+    private var cbThen: ((Result) -> Unit)? = null
+    private var cbProgress: ((Progress) -> Unit)? = null
+    private var cbFail: ((Exception) -> Unit)? = null
+    private var cbFinish: (() -> Unit)? = null
+    private var exception: Exception? = null
+
+    init {
+        this.task = InnerAsyncTask()
+    }
+
+    fun onDone(cb: (Result) -> Unit): BackgroundTask<Result, Progress> {
+        this.cbThen = cb
+        return this
+    }
+
+    fun onProgress(cb: (Progress) -> Unit): BackgroundTask<Result, Progress> {
+        this.cbProgress = cb
+        return this
+    }
+
+    fun onFail(cb: (Exception) -> Unit): BackgroundTask<Result, Progress> {
+        this.cbFail = cb
+        return this
+    }
+
+    fun onFinish(cb: () -> Unit): BackgroundTask<Result, Progress> {
+        this.cbFinish = cb
+        return this
+    }
+
+    fun onDoneUI(cb: (Result) -> Unit): BackgroundTask<Result, Progress> {
+        return onDone({ r -> UIHandler().post { cb(r) } })
+    }
+
+    fun onProgressUI(cb: (Progress) -> Unit): BackgroundTask<Result, Progress> {
+        return onProgress({ p -> UIHandler().post { cb(p) } })
+    }
+
+    fun onFailUI(cb: (Exception) -> Unit): BackgroundTask<Result, Progress> {
+        return onFail({ e -> UIHandler().post { cb(e) } })
+    }
+
+    fun onFinishUI(cb: () -> Unit): BackgroundTask<Result, Progress> {
+        return onFinish({ UIHandler().post(cb) })
+    }
+
+    fun cancel(): Boolean {
+        return task.cancel(true)
+    }
+
+    fun execute(): BackgroundTask<Result, Progress> {
+        task.execute()
+        return this
+    }
+
+    val immediately: Result
+        @Throws(Exception::class)
+        get() {
+            val result = task.get()
+            return if (exception == null) {
+                result
+            } else {
+                throw exception!!
+            }
+        }
+
+    protected fun fail(ex: Exception) {
+        exception = ex
+        ex.printStackTrace()
+        Logger.error(ex)
+
+        if (!task.isCancelled && cbFail != null) {
+            cbFail!!(ex)
+        }
+    }
+
+    protected fun progress(value: Progress) {
+        if (!task.isCancelled && exception == null && cbProgress != null) {
+            cbProgress!!(value)
+        }
+    }
+
+    @Throws(Exception::class)
+    protected abstract fun doInBackground(): Result
+
+    private inner class InnerAsyncTask : AsyncTask<Void, Progress, Result>() {
+        override fun onPostExecute(result: Result) {
+            if (!isCancelled && exception == null && cbThen != null) {
+                cbThen!!(result)
+            }
+            if (cbFinish != null) {
+                cbFinish!!()
+            }
+        }
+
+        override fun doInBackground(vararg params: Void): Result? {
+            try {
+                return this@BackgroundTask.doInBackground()
+            } catch (ex: Exception) {
+                fail(ex)
+                return null
+            }
+
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.java b/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.java
deleted file mode 100644
index dbb6fccd..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.java
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.util;
-
-import android.app.Activity;
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.graphics.Matrix;
-import android.media.ExifInterface;
-import android.os.Environment;
-import net.lacolaco.smileessence.logging.Logger;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.OutputStream;
-
-public class BitmapOptimizer {
-
-    // -------------------------- STATIC METHODS --------------------------
-
-    public static String rotateImageByExif(Activity activity, String filePath) {
-        filePath = filePath.replace("file://", "");
-        int degree = getRotateDegreeFromExif(filePath);
-        if (degree > 0) {
-            OutputStream out = null;
-            Bitmap bitmap = null;
-            Bitmap rotatedImage = null;
-            try {
-                Matrix mat = new Matrix();
-                mat.postRotate(degree);
-                BitmapFactory.Options opt = new BitmapFactory.Options();
-                opt.inJustDecodeBounds = true;
-                BitmapFactory.decodeFile(filePath, opt);
-                int width = 480;
-                int scale = 1;
-                if (opt.outWidth > width) {
-                    scale = opt.outWidth / width + 2;
-                }
-                opt.inJustDecodeBounds = false;
-                opt.inSampleSize = scale;
-                bitmap = BitmapFactory.decodeFile(filePath, opt);
-                rotatedImage = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), mat, true);
-                File file = new File(filePath);
-                String outPath = activity.getExternalFilesDir(Environment.DIRECTORY_PICTURES) + "/" + file.getName();
-                Logger.debug(outPath);
-                out = new FileOutputStream(outPath);
-                rotatedImage.compress(Bitmap.CompressFormat.JPEG, 100, out);
-                return outPath;
-            } catch (Exception e) {
-                e.printStackTrace();
-                Logger.error(e);
-            } finally {
-                if (out != null) {
-                    try {
-                        out.close();
-                    } catch (IOException e) {
-                        e.printStackTrace();
-                        Logger.error(e);
-                    }
-                }
-                if (bitmap != null) {
-                    bitmap.recycle();
-                }
-                if (rotatedImage != null) {
-                    rotatedImage.recycle();
-                }
-            }
-        }
-        return filePath;
-    }
-
-    private static int getRotateDegreeFromExif(String filePath) {
-        int degree = 0;
-        try {
-            ExifInterface exifInterface = new ExifInterface(filePath);
-            int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_UNDEFINED);
-            if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
-                degree = 90;
-            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_180) {
-                degree = 180;
-            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
-                degree = 270;
-            }
-            if (degree != 0) {
-                exifInterface.setAttribute(ExifInterface.TAG_ORIENTATION, "0");
-                exifInterface.saveAttributes();
-            }
-        } catch (IOException e) {
-            degree = -1;
-            e.printStackTrace();
-            Logger.error(e);
-        }
-        Logger.debug("Exif degree = " + degree);
-        return degree;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.kt b/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.kt
new file mode 100644
index 00000000..b49c9f08
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/BitmapOptimizer.kt
@@ -0,0 +1,122 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.util
+
+import android.app.Activity
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.graphics.Matrix
+import android.media.ExifInterface
+import android.os.Environment
+import net.lacolaco.smileessence.logging.Logger
+
+import java.io.File
+import java.io.FileOutputStream
+import java.io.IOException
+import java.io.OutputStream
+
+object BitmapOptimizer {
+
+    // -------------------------- STATIC METHODS --------------------------
+
+    fun rotateImageByExif(activity: Activity, filePath: String): String {
+        var filePath = filePath
+        filePath = filePath.replace("file://", "")
+        val degree = getRotateDegreeFromExif(filePath)
+        if (degree > 0) {
+            var out: OutputStream? = null
+            var bitmap: Bitmap? = null
+            var rotatedImage: Bitmap? = null
+            try {
+                val mat = Matrix()
+                mat.postRotate(degree.toFloat())
+                val opt = BitmapFactory.Options()
+                opt.inJustDecodeBounds = true
+                BitmapFactory.decodeFile(filePath, opt)
+                val width = 480
+                var scale = 1
+                if (opt.outWidth > width) {
+                    scale = opt.outWidth / width + 2
+                }
+                opt.inJustDecodeBounds = false
+                opt.inSampleSize = scale
+                bitmap = BitmapFactory.decodeFile(filePath, opt)
+                rotatedImage = Bitmap.createBitmap(bitmap, 0, 0, bitmap!!.width, bitmap.height, mat, true)
+                val file = File(filePath)
+                val outPath = activity.getExternalFilesDir(Environment.DIRECTORY_PICTURES).toString() + "/" + file.name
+                Logger.debug(outPath)
+                out = FileOutputStream(outPath)
+                rotatedImage!!.compress(Bitmap.CompressFormat.JPEG, 100, out)
+                return outPath
+            } catch (e: Exception) {
+                e.printStackTrace()
+                Logger.error(e)
+            } finally {
+                if (out != null) {
+                    try {
+                        out.close()
+                    } catch (e: IOException) {
+                        e.printStackTrace()
+                        Logger.error(e)
+                    }
+
+                }
+                if (bitmap != null) {
+                    bitmap.recycle()
+                }
+                if (rotatedImage != null) {
+                    rotatedImage.recycle()
+                }
+            }
+        }
+        return filePath
+    }
+
+    private fun getRotateDegreeFromExif(filePath: String): Int {
+        var degree = 0
+        try {
+            val exifInterface = ExifInterface(filePath)
+            val orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_UNDEFINED)
+            if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
+                degree = 90
+            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_180) {
+                degree = 180
+            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
+                degree = 270
+            }
+            if (degree != 0) {
+                exifInterface.setAttribute(ExifInterface.TAG_ORIENTATION, "0")
+                exifInterface.saveAttributes()
+            }
+        } catch (e: IOException) {
+            degree = -1
+            e.printStackTrace()
+            Logger.error(e)
+        }
+
+        Logger.debug("Exif degree = " + degree)
+        return degree
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BitmapThumbnailTask.java b/app/src/main/java/net/lacolaco/smileessence/util/BitmapThumbnailTask.kt
index 0aa292cb..6e353716 100644
--- a/app/src/main/java/net/lacolaco/smileessence/util/BitmapThumbnailTask.java
+++ b/app/src/main/java/net/lacolaco/smileessence/util/BitmapThumbnailTask.kt
@@ -22,42 +22,34 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.util;
+package net.lacolaco.smileessence.util
 
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.media.ThumbnailUtils;
-import android.os.AsyncTask;
-import android.widget.ImageView;
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.media.ThumbnailUtils
+import android.os.AsyncTask
+import android.widget.ImageView
 
-public class BitmapThumbnailTask extends AsyncTask<Void, Void, Bitmap> {
+class BitmapThumbnailTask
+// --------------------------- CONSTRUCTORS ---------------------------
 
-    // ------------------------------ FIELDS ------------------------------
+(
+        // ------------------------------ FIELDS ------------------------------
 
-    private final String filePath;
-    private final ImageView imageView;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public BitmapThumbnailTask(String filePath, ImageView imageView) {
-        this.filePath = filePath;
-        this.imageView = imageView;
-    }
+        private val filePath: String, private val imageView: ImageView?) : AsyncTask<Void, Void, Bitmap?>() {
 
     // ------------------------ OVERRIDE METHODS ------------------------
 
-    @Override
-    protected void onPostExecute(Bitmap bitmap) {
+    override fun onPostExecute(bitmap: Bitmap?) {
         if (bitmap != null && imageView != null) {
-            imageView.setImageBitmap(bitmap);
+            imageView.setImageBitmap(bitmap)
         }
     }
 
-    @Override
-    protected Bitmap doInBackground(Void... params) {
-        BitmapFactory.Options opt = new BitmapFactory.Options();
-        opt.inPurgeable = true; // GC可能にする
-        opt.inSampleSize = 2;
+    override fun doInBackground(vararg params: Void): Bitmap? {
+        val opt = BitmapFactory.Options()
+        opt.inPurgeable = true // GC可能にする
+        opt.inSampleSize = 2
         //        ContentResolver resolver = activity.getContentResolver();
         //        Cursor cursor = resolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, MediaStore.Images.ImageColumns.DATA + " = ?", new String[]{filePath}, null);
         //        if(cursor.moveToFirst())
@@ -67,6 +59,6 @@ public class BitmapThumbnailTask extends AsyncTask<Void, Void, Bitmap> {
         //            return MediaStore.Images.Thumbnails.getThumbnail(resolver, id, MediaStore.Images.Thumbnails.MICRO_KIND, opt);
         //        }
         //        return null;
-        return ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(filePath), 100, 100, ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
+        return ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(filePath), 100, 100, ThumbnailUtils.OPTIONS_RECYCLE_INPUT)
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.java b/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.java
deleted file mode 100644
index 151498c3..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.util;
-
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.os.AsyncTask;
-import android.widget.ImageView;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.net.URL;
-
-public class BitmapURLTask extends AsyncTask<Void, Void, Bitmap> {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private final String url;
-    private final ImageView imageView;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public BitmapURLTask(String url, ImageView imageView) {
-        this.url = url;
-        this.imageView = imageView;
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    protected void onPostExecute(Bitmap bitmap) {
-        if (imageView != null) {
-            imageView.setImageBitmap(bitmap);
-        }
-    }
-
-    @Override
-    protected Bitmap doInBackground(Void... params) {
-        InputStream inputStream = null;
-        try {
-            inputStream = new URL(url).openStream();
-            BitmapFactory.Options opt = new BitmapFactory.Options();
-            opt.inPurgeable = true; // GC可能にする
-            return BitmapFactory.decodeStream(inputStream, null, opt);
-        } catch (IOException e) {
-            e.printStackTrace();
-            return null;
-        } finally {
-            if (inputStream != null) {
-                try {
-                    inputStream.close();
-                } catch (IOException e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.kt b/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.kt
new file mode 100644
index 00000000..f71e4afb
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/BitmapURLTask.kt
@@ -0,0 +1,68 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.util
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.os.AsyncTask
+import android.widget.ImageView
+
+import java.io.IOException
+import java.io.InputStream
+import java.net.URL
+
+class BitmapURLTask
+// --------------------------- CONSTRUCTORS ---------------------------
+
+(
+        // ------------------------------ FIELDS ------------------------------
+
+        private val url: String, private val imageView: ImageView?) : AsyncTask<Void, Void, Bitmap>() {
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onPostExecute(bitmap: Bitmap) {
+        imageView?.setImageBitmap(bitmap)
+    }
+
+    override fun doInBackground(vararg params: Void): Bitmap? {
+        var inputStream: InputStream? = null
+        try {
+            inputStream = URL(url).openStream()
+            val opt = BitmapFactory.Options()
+            opt.inPurgeable = true // GC可能にする
+            return BitmapFactory.decodeStream(inputStream, null, opt)
+        } catch (e: IOException) {
+            e.printStackTrace()
+            return null
+        } finally {
+            try {
+                inputStream?.close()
+            } catch (e: IOException) {
+                e.printStackTrace()
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/Consumer.java b/app/src/main/java/net/lacolaco/smileessence/util/Consumer.java
deleted file mode 100644
index a8712293..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/Consumer.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-public interface Consumer<T> {
-    void accept(T t);
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/Function.java b/app/src/main/java/net/lacolaco/smileessence/util/Function.java
deleted file mode 100644
index 5e374e8e..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/Function.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-public interface Function<T, R> {
-    R apply(T t);
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/IntentUtils.java b/app/src/main/java/net/lacolaco/smileessence/util/IntentUtils.kt
index 9ec4aa46..48b6f9e4 100644
--- a/app/src/main/java/net/lacolaco/smileessence/util/IntentUtils.java
+++ b/app/src/main/java/net/lacolaco/smileessence/util/IntentUtils.kt
@@ -22,19 +22,17 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.util;
+package net.lacolaco.smileessence.util
 
-import android.app.Activity;
-import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.content.pm.ResolveInfo;
-import android.net.Uri;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
+import android.app.Activity
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.content.pm.ResolveInfo
+import android.net.Uri
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
 
-import java.util.List;
-
-public class IntentUtils {
+object IntentUtils {
 
     // -------------------------- STATIC METHODS --------------------------
 
@@ -45,14 +43,14 @@ public class IntentUtils {
      * @param intent
      * @return
      */
-    public static boolean startActivityIfFound(Activity activity, Intent intent) {
+    fun startActivityIfFound(activity: Activity, intent: Intent): Boolean {
         if (canStartActivity(activity, intent)) {
-            activity.startActivity(intent);
-            return true;
+            activity.startActivity(intent)
+            return true
         } else {
-            Application.toast(R.string.notice_error_start_activity);
+            Application.toast(R.string.notice_error_start_activity)
         }
-        return false;
+        return false
     }
 
     /**
@@ -62,10 +60,10 @@ public class IntentUtils {
      * @param intent
      * @return
      */
-    public static boolean canStartActivity(Activity activity, Intent intent) {
-        PackageManager packageManager = activity.getPackageManager();
-        List<ResolveInfo> infos = packageManager.queryIntentActivities(intent, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT);
-        return !infos.isEmpty();
+    fun canStartActivity(activity: Activity, intent: Intent): Boolean {
+        val packageManager = activity.packageManager
+        val infos = packageManager.queryIntentActivities(intent, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT)
+        return !infos.isEmpty()
     }
 
     /**
@@ -76,18 +74,18 @@ public class IntentUtils {
      * @param requestCode
      * @return
      */
-    public static boolean startActivityForResultIfFound(Activity activity, Intent intent, int requestCode) {
+    fun startActivityForResultIfFound(activity: Activity, intent: Intent, requestCode: Int): Boolean {
         if (canStartActivity(activity, intent)) {
-            activity.startActivityForResult(intent, requestCode);
-            return true;
+            activity.startActivityForResult(intent, requestCode)
+            return true
         } else {
-            Application.toast(R.string.notice_error_start_activity);
+            Application.toast(R.string.notice_error_start_activity)
         }
-        return false;
+        return false
     }
 
-    public static boolean openUri(Activity activity, String uriString) {
-        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(uriString));
-        return startActivityIfFound(activity, intent);
+    fun openUri(activity: Activity, uriString: String): Boolean {
+        val intent = Intent(Intent.ACTION_VIEW, Uri.parse(uriString))
+        return startActivityIfFound(activity, intent)
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/ListUtils.java b/app/src/main/java/net/lacolaco/smileessence/util/ListUtils.java
deleted file mode 100644
index 36ade3e6..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/ListUtils.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class ListUtils {
-    public static <T, R> List<R> map(List<T> orig, Function<T, R> func) {
-        List<R> result = new ArrayList<>(orig.size());
-        for (T item : orig) {
-            result.add(func.apply(item));
-        }
-        return result;
-    }
-
-    public static <T> List<T> filter(Iterable<T> orig, Predicate<T> pred) {
-        List<T> result = new ArrayList<>();
-        for (T item : orig) {
-            if (pred.test(item)) {
-                result.add(item);
-            }
-        }
-        return result;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/Predicate.java b/app/src/main/java/net/lacolaco/smileessence/util/Predicate.java
deleted file mode 100644
index 400310a9..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/Predicate.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-public interface Predicate<T> {
-    boolean test(T t);
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/StringUtils.java b/app/src/main/java/net/lacolaco/smileessence/util/StringUtils.kt
index 07dedb46..cdfe59f5 100644
--- a/app/src/main/java/net/lacolaco/smileessence/util/StringUtils.java
+++ b/app/src/main/java/net/lacolaco/smileessence/util/StringUtils.kt
@@ -22,40 +22,40 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.util;
+package net.lacolaco.smileessence.util
 
-import android.annotation.SuppressLint;
+import android.annotation.SuppressLint
 
-import java.text.SimpleDateFormat;
-import java.util.Calendar;
-import java.util.Date;
+import java.text.SimpleDateFormat
+import java.util.Calendar
+import java.util.Date
 
-public class StringUtils {
+object StringUtils {
 
     // -------------------------- STATIC METHODS --------------------------
 
     @SuppressLint("SimpleDateFormat")
-    public static String dateToString(Date date) {
-        Calendar current = Calendar.getInstance();
-        Calendar cal = Calendar.getInstance();
-        cal.setTime(date);
+    fun dateToString(date: Date): String {
+        val current = Calendar.getInstance()
+        val cal = Calendar.getInstance()
+        cal.time = date
 
-        if (isSameYear(current, cal)) {
+        return if (isSameYear(current, cal)) {
             if (isSameDay(current, cal)) {
-                return new SimpleDateFormat("HH:mm:ss").format(date);
+                SimpleDateFormat("HH:mm:ss").format(date)
             } else {
-                return new SimpleDateFormat("MM/dd HH:mm:ss").format(date);
+                SimpleDateFormat("MM/dd HH:mm:ss").format(date)
             }
         } else {
-            return new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(date);
+            SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(date)
         }
     }
 
-    private static boolean isSameDay(Calendar current, Calendar cal) {
-        return cal.get(Calendar.DAY_OF_YEAR) == current.get(Calendar.DAY_OF_YEAR);
+    private fun isSameDay(current: Calendar, cal: Calendar): Boolean {
+        return cal.get(Calendar.DAY_OF_YEAR) == current.get(Calendar.DAY_OF_YEAR)
     }
 
-    private static boolean isSameYear(Calendar current, Calendar cal) {
-        return cal.get(Calendar.YEAR) == current.get(Calendar.YEAR);
+    private fun isSameYear(current: Calendar, cal: Calendar): Boolean {
+        return cal.get(Calendar.YEAR) == current.get(Calendar.YEAR)
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/SystemServiceHelper.java b/app/src/main/java/net/lacolaco/smileessence/util/SystemServiceHelper.kt
index 919ef351..efed67ca 100644
--- a/app/src/main/java/net/lacolaco/smileessence/util/SystemServiceHelper.java
+++ b/app/src/main/java/net/lacolaco/smileessence/util/SystemServiceHelper.kt
@@ -22,32 +22,32 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.util;
+package net.lacolaco.smileessence.util
 
-import android.app.Activity;
-import android.content.ClipData;
-import android.content.ClipboardManager;
-import android.content.Context;
-import android.view.View;
-import android.view.inputmethod.InputMethodManager;
+import android.app.Activity
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.view.View
+import android.view.inputmethod.InputMethodManager
 
-public class SystemServiceHelper {
-    public static void hideIM(Context context, View view) {
+object SystemServiceHelper {
+    fun hideIM(context: Context, view: View?) {
         if (view != null) {
-            InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
-            imm.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.RESULT_UNCHANGED_SHOWN);
+            val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
+            imm.hideSoftInputFromWindow(view.windowToken, InputMethodManager.RESULT_UNCHANGED_SHOWN)
         }
     }
 
-    public static void showIM(Context context, View view) {
+    fun showIM(context: Context, view: View?) {
         if (view != null) {
-            InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
-            imm.showSoftInput(view, InputMethodManager.RESULT_UNCHANGED_SHOWN);
+            val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
+            imm.showSoftInput(view, InputMethodManager.RESULT_UNCHANGED_SHOWN)
         }
     }
 
-    public static void copyToClipboard(Context context, String label, String text) {
-        ClipboardManager manager = (ClipboardManager) context.getSystemService(Activity.CLIPBOARD_SERVICE);
-        manager.setPrimaryClip(ClipData.newPlainText(label, text));
+    fun copyToClipboard(context: Context, label: String, text: String) {
+        val manager = context.getSystemService(Activity.CLIPBOARD_SERVICE) as ClipboardManager
+        manager.primaryClip = ClipData.newPlainText(label, text)
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIHandler.java b/app/src/main/java/net/lacolaco/smileessence/util/UIHandler.kt
index f228f23f..5c9898a2 100644
--- a/app/src/main/java/net/lacolaco/smileessence/util/UIHandler.java
+++ b/app/src/main/java/net/lacolaco/smileessence/util/UIHandler.kt
@@ -22,13 +22,9 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.util;
+package net.lacolaco.smileessence.util
 
-import android.os.Handler;
-import android.os.Looper;
+import android.os.Handler
+import android.os.Looper
 
-public class UIHandler extends Handler {
-    public UIHandler() {
-        super(Looper.getMainLooper());
-    }
-}
+class UIHandler : Handler(Looper.getMainLooper())
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.java b/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.java
deleted file mode 100644
index 1cf4efeb..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-import net.lacolaco.smileessence.entity.RBinding;
-
-import java.util.*;
-
-public abstract class UIObservable {
-    private Map<Object, UIObserver> observers = new WeakHashMap<>();
-
-    public void addObserver(Object weakKey, UIObserver observer) {
-        synchronized (this) {
-            observers.put(weakKey, observer);
-        }
-    }
-
-    public UIObserver removeObserver(Object weakKey) {
-        synchronized (this) {
-            return observers.remove(weakKey);
-        }
-    }
-
-    protected void notifyChange(RBinding flag) {
-        notifyChange(EnumSet.of(flag));
-    }
-
-    protected void notifyChange(EnumSet<RBinding> flags) {
-        List<UIObserver> obs = new ArrayList<>();
-        synchronized (this) {
-            obs.addAll(observers.values());
-        }
-
-        new UIHandler().post(() -> {
-            for (UIObserver observer : obs) {
-                observer.update(flags);
-            }
-        });
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.kt b/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.kt
new file mode 100644
index 00000000..a8f89585
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/UIObservable.kt
@@ -0,0 +1,38 @@
+package net.lacolaco.smileessence.util
+
+import net.lacolaco.smileessence.entity.RBinding
+
+import java.util.*
+
+abstract class UIObservable {
+    private val observers = WeakHashMap<Any, (EnumSet<RBinding>) -> Unit>()
+
+    fun addObserver(weakKey: Any, observer: (EnumSet<RBinding>) -> Unit) {
+        synchronized(this) {
+            observers.put(weakKey, observer)
+        }
+    }
+
+    fun removeObserver(weakKey: Any) {
+        synchronized(this) {
+            observers.remove(weakKey)
+        }
+    }
+
+    protected fun notifyChange(flag: RBinding) {
+        notifyChange(EnumSet.of(flag))
+    }
+
+    protected fun notifyChange(flags: EnumSet<RBinding>) {
+        val obs = ArrayList<(EnumSet<RBinding>) -> Unit>()
+        synchronized(this) {
+            obs.addAll(observers.values)
+        }
+
+        UIHandler().post {
+            for (observer in obs) {
+                observer(flags)
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIObserver.java b/app/src/main/java/net/lacolaco/smileessence/util/UIObserver.java
deleted file mode 100644
index 6a621c61..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/UIObserver.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-import net.lacolaco.smileessence.entity.RBinding;
-
-import java.util.EnumSet;
-
-public interface UIObserver {
-    void update(EnumSet<RBinding> flags);
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.java b/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.java
deleted file mode 100644
index a1d8957a..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package net.lacolaco.smileessence.util;
-
-import java.util.HashMap;
-import java.util.Map;
-
-// UIObserver と UIObservable のセットを管理するオブジェクトだよ〜〜
-public class UIObserverBundle {
-    private Map<UIObservable, UIObserver> map = new HashMap<>();
-
-    public void detachAll() {
-        for (Map.Entry<UIObservable, UIObserver> entry : map.entrySet()) {
-            entry.getKey().removeObserver(this);
-        }
-        map.clear();
-    }
-
-    public UIObserver attach(UIObservable observable, UIObserver observer) {
-        observable.addObserver(this, observer);
-        map.put(observable, observer);
-        return observer;
-    }
-
-    @Override
-    protected void finalize() throws Throwable {
-        try {
-            super.finalize();
-        } finally {
-            detachAll();
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.kt b/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.kt
new file mode 100644
index 00000000..f6c8403b
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/UIObserverBundle.kt
@@ -0,0 +1,26 @@
+package net.lacolaco.smileessence.util
+
+import net.lacolaco.smileessence.entity.RBinding
+import java.util.*
+
+// UIObserver と UIObservable のセットを管理するオブジェクトだよ〜〜
+class UIObserverBundle {
+    private val map = HashMap<UIObservable, (EnumSet<RBinding>) -> Unit>()
+
+    fun detachAll() {
+        for ((key) in map) {
+            key.removeObserver(this)
+        }
+        map.clear()
+    }
+
+    fun attach(observable: UIObservable, observer: (EnumSet<RBinding>) -> Unit): (EnumSet<RBinding>) -> Unit {
+        observable.addObserver(this, observer)
+        map.put(observable, observer)
+        return observer
+    }
+
+    protected fun finalize() {
+        detachAll()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.java b/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.java
deleted file mode 100644
index 33fc05ac..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.java
+++ /dev/null
@@ -1,61 +0,0 @@
-package net.lacolaco.smileessence.view;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.graphics.Canvas;
-import android.graphics.Paint;
-import android.util.AttributeSet;
-import android.widget.RelativeLayout;
-import net.lacolaco.smileessence.R;
-
-
-public class ColoredRelativeLayout extends RelativeLayout {
-    public static final int HIGHLIGHT_NONE = 0;
-    private final Paint paint = new Paint();
-    private int highlightColors[] = new int[4];
-    private boolean showAccent = false;
-
-    public ColoredRelativeLayout(Context context) {
-        this(context, null);
-    }
-
-    public ColoredRelativeLayout(Context context, AttributeSet attrs) {
-        this(context, attrs, 0);
-    }
-
-    public ColoredRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
-        this(context, attrs, defStyleAttr, 0);
-    }
-
-    public ColoredRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
-
-        setWillNotDraw(false);
-
-        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ColoredRelativeLayout);
-        highlightColors[0] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_none, R.color.black);
-        highlightColors[1] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type1, R.color.orange);
-        highlightColors[2] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type2, R.color.green);
-        highlightColors[3] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type3, R.color.metro_blue);
-        setHighlight(HIGHLIGHT_NONE);
-        paint.setColor(ta.getColor(R.styleable.ColoredRelativeLayout_accent_color, R.color.red));
-        paint.setStyle(Paint.Style.STROKE);
-        paint.setStrokeWidth(3);
-        ta.recycle();
-    }
-
-    @Override
-    protected void onDraw(Canvas canvas) {
-        super.onDraw(canvas);
-        if (showAccent)
-            canvas.drawLine(1, 0, 1, getMeasuredHeight(), paint);
-    }
-
-    public void setAccentVisibility(boolean yes) {
-        showAccent = yes;
-    }
-
-    public void setHighlight(int type) {
-        setBackgroundColor(highlightColors[type]);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.kt b/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.kt
new file mode 100644
index 00000000..0bf69378
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/ColoredRelativeLayout.kt
@@ -0,0 +1,50 @@
+package net.lacolaco.smileessence.view
+
+import android.content.Context
+import android.content.res.TypedArray
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.util.AttributeSet
+import android.widget.RelativeLayout
+import net.lacolaco.smileessence.R
+
+
+class ColoredRelativeLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0, defStyleRes: Int = 0) : RelativeLayout(context, attrs, defStyleAttr, defStyleRes) {
+    private val paint = Paint()
+    private val highlightColors = IntArray(4)
+    private var showAccent = false
+
+    init {
+
+        setWillNotDraw(false)
+
+        val ta = context.obtainStyledAttributes(attrs, R.styleable.ColoredRelativeLayout)
+        highlightColors[0] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_none, R.color.black)
+        highlightColors[1] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type1, R.color.orange)
+        highlightColors[2] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type2, R.color.green)
+        highlightColors[3] = ta.getColor(R.styleable.ColoredRelativeLayout_highlight_type3, R.color.metro_blue)
+        setHighlight(HIGHLIGHT_NONE)
+        paint.color = ta.getColor(R.styleable.ColoredRelativeLayout_accent_color, R.color.red)
+        paint.style = Paint.Style.STROKE
+        paint.strokeWidth = 3f
+        ta.recycle()
+    }
+
+    override fun onDraw(canvas: Canvas) {
+        super.onDraw(canvas)
+        if (showAccent)
+            canvas.drawLine(1f, 0f, 1f, measuredHeight.toFloat(), paint)
+    }
+
+    fun setAccentVisibility(yes: Boolean) {
+        showAccent = yes
+    }
+
+    fun setHighlight(type: Int) {
+        setBackgroundColor(highlightColors[type])
+    }
+
+    companion object {
+        val HIGHLIGHT_NONE = 0
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/DialogHelper.java b/app/src/main/java/net/lacolaco/smileessence/view/DialogHelper.kt
index 3a0003d6..c9b4a428 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/DialogHelper.java
+++ b/app/src/main/java/net/lacolaco/smileessence/view/DialogHelper.kt
@@ -22,38 +22,38 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.view;
+package net.lacolaco.smileessence.view
 
-import android.app.Activity;
-import net.lacolaco.smileessence.view.dialog.StackableDialogFragment;
+import android.app.Activity
+import net.lacolaco.smileessence.view.dialog.StackableDialogFragment
 
-import java.util.ArrayList;
-import java.util.LinkedHashSet;
-import java.util.Set;
-import java.util.UUID;
+import java.util.ArrayList
+import java.util.LinkedHashSet
+import java.util.UUID
 
 /**
  * DialogFragment のタグの一覧を保持し「全てのダイアログを閉じる」機能を提供するヘルパークラス
  */
-public class DialogHelper {
-    private static Set<String> dialogStack = new LinkedHashSet<>();
+object DialogHelper {
+    private val dialogStack = LinkedHashSet<String>()
 
-    public synchronized static void closeAll(Activity activity) {
-        for (String tag : new ArrayList<>(dialogStack)) {
-            StackableDialogFragment dialogFragment = (StackableDialogFragment) activity.getFragmentManager().findFragmentByTag(tag);
-            if (dialogFragment != null) {
-                dialogFragment.dismiss();
-            }
+    @Synchronized
+    fun closeAll(activity: Activity) {
+        for (tag in ArrayList(dialogStack)) {
+            val dialogFragment = activity.fragmentManager.findFragmentByTag(tag) as StackableDialogFragment?
+            dialogFragment?.dismiss()
         }
     }
 
-    public synchronized static int showDialog(Activity activity, StackableDialogFragment dialogFragment) {
-        String tag = "stackingDialog:" + dialogFragment.getClass().getSimpleName() + ":" + UUID.randomUUID();
-        dialogStack.add(tag);
-        return dialogFragment.show(activity.getFragmentManager().beginTransaction(), tag);
+    @Synchronized
+    fun showDialog(activity: Activity, dialogFragment: StackableDialogFragment): Int {
+        val tag = "stackingDialog:" + dialogFragment.javaClass.simpleName + ":" + UUID.randomUUID()
+        dialogStack.add(tag)
+        return dialogFragment.show(activity.fragmentManager.beginTransaction(), tag)
     }
 
-    public synchronized static void unregisterDialog(String tag) {
-        dialogStack.remove(tag);
+    @Synchronized
+    fun unregisterDialog(tag: String) {
+        dialogStack.remove(tag)
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.java b/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.java
deleted file mode 100644
index e0a4a651..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.java
+++ /dev/null
@@ -1,29 +0,0 @@
-package net.lacolaco.smileessence.view;
-
-import android.content.Context;
-import android.util.AttributeSet;
-import android.view.ViewGroup;
-import android.widget.ListView;
-
-public class ExpandedListView extends ListView {
-    public ExpandedListView(Context context) {
-        super(context);
-    }
-
-    public ExpandedListView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    public ExpandedListView(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-    }
-
-    @Override
-    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
-        super.onMeasure(widthMeasureSpec, expandSpec);
-
-        ViewGroup.LayoutParams params = getLayoutParams();
-        params.height = getMeasuredHeight();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.kt b/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.kt
new file mode 100644
index 00000000..288354ba
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/ExpandedListView.kt
@@ -0,0 +1,23 @@
+package net.lacolaco.smileessence.view
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ListView
+
+class ExpandedListView : ListView {
+    constructor(context: Context) : super(context)
+
+    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
+
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    public override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        val expandSpec = View.MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE shr 2, View.MeasureSpec.AT_MOST)
+        super.onMeasure(widthMeasureSpec, expandSpec)
+
+        val params = layoutParams
+        params.height = measuredHeight
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/Partials.java b/app/src/main/java/net/lacolaco/smileessence/view/Partials.java
deleted file mode 100644
index fc0e35cb..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/Partials.java
+++ /dev/null
@@ -1,229 +0,0 @@
-package net.lacolaco.smileessence.view;
-
-import android.app.Activity;
-import android.text.Html;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ImageView;
-import android.widget.ListView;
-import android.widget.TextView;
-import com.android.volley.toolbox.NetworkImageView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.ImageCache;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.entity.RBinding;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.util.StringUtils;
-import net.lacolaco.smileessence.util.UIObserverBundle;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-import net.lacolaco.smileessence.view.dialog.MessageDetailDialogFragment;
-import net.lacolaco.smileessence.view.dialog.StatusDetailDialogFragment;
-import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment;
-import net.lacolaco.smileessence.view.listener.ListItemClickListener;
-
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.List;
-
-public class Partials {
-    public static View getTweetView(Tweet tweet, Activity activity, View convertView, boolean expandEmbeddedTweets) {
-        if (convertView == null) {
-            convertView = activity.getLayoutInflater().inflate(R.layout.list_item_status, null);
-        }
-        UIObserverBundle bundle = (UIObserverBundle) convertView.getTag();
-        if (bundle != null) {
-            bundle.detachAll();
-        } else {
-            bundle = new UIObserverBundle();
-            convertView.setTag(bundle);
-        }
-
-        convertView.setOnClickListener(new ListItemClickListener(activity, () -> DialogHelper.showDialog(activity, StatusDetailDialogFragment.newInstance(tweet))));
-
-        updateViewUser(tweet, activity, convertView);
-        updateViewBody(tweet, activity, convertView);
-        updateViewFavorited(tweet, convertView);
-        updateViewEmbeddeds(tweet, activity, convertView, expandEmbeddedTweets);
-
-        final WeakReference<View> weakView = new WeakReference<>(convertView);
-        final WeakReference<Activity> weakActivity = new WeakReference<>(activity);
-        bundle.attach(tweet.getOriginalTweet(), changes -> {
-            View strongView = weakView.get();
-            if (strongView != null && changes.contains(RBinding.FAVORITERS))
-                updateViewFavorited(tweet, strongView);
-        });
-        bundle.attach(tweet.getUser(), changes -> {
-            View strongView = weakView.get();
-            Activity strongActivity = weakActivity.get();
-            if (strongView != null && strongActivity != null && changes.contains(RBinding.BASIC))
-                updateViewUser(tweet, strongActivity, strongView);
-        });
-
-        return convertView;
-    }
-
-
-    private static void updateViewEmbeddeds(Tweet tweet, Activity activity, View convertView, boolean expandEmbeddedTweets) {
-        final ListView embeddedStatus = (ListView) convertView.findViewById(R.id.listview_status_embedded_status);
-        if (expandEmbeddedTweets) {
-            final List<Tweet> list = new ArrayList<>();
-            CustomListAdapter<Tweet> embeddedTweetsAdapter = new CustomListAdapter<Tweet>() {
-                @Override
-                protected List<Tweet> getList() {
-                    return list;
-                }
-
-                @Override
-                public View getView(int position, View convertView, ViewGroup parent) {
-                    return Partials.getTweetView(getItem(position), activity, convertView, false);
-                }
-            };
-
-            Account account = Application.getCurrentWorld().getAccount();
-            for (long id : tweet.getEmbeddedStatusIDs()) {
-                Tweet.fetchTask(id, account).onDone(t -> list.add(t)).execute();
-            }
-            embeddedStatus.setAdapter(embeddedTweetsAdapter);
-            embeddedStatus.setVisibility(View.VISIBLE);
-        } else {
-            embeddedStatus.setAdapter(null); // view may be reused, set null explicitly
-            embeddedStatus.setVisibility(View.GONE);
-        }
-    }
-
-    private static void updateViewUser(Tweet tweet, Activity activity, View convertView) {
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-
-        NetworkImageView icon = (NetworkImageView) convertView.findViewById(R.id.imageview_status_icon);
-        String iconUrl = tweet.getOriginalTweet().getUser().getProfileImageUrlOriginal();
-        icon.setImageUrl(iconUrl, ImageCache.getImageLoader());
-        icon.setOnClickListener(v -> onIconClick(tweet, activity));
-
-        TextView header = (TextView) convertView.findViewById(R.id.textview_status_header);
-        header.setTextSize(textSize);
-        header.setText(tweet.getOriginalTweet().getUser().getFormattedName());
-
-        ((ColoredRelativeLayout) convertView).setAccentVisibility(tweet.getUser() == Application.getCurrentWorld().getAccount().getUser());
-    }
-
-    private static void updateViewBody(Tweet tweet, Activity activity, View convertView) {
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-
-        TextView content = (TextView) convertView.findViewById(R.id.textview_status_text);
-        content.setTextSize(textSize);
-        String rawText = tweet.getOriginalTweet().getText();
-        content.setText(rawText);
-        TextView footer = (TextView) convertView.findViewById(R.id.textview_status_footer);
-        footer.setTextSize(textSize - 2);
-        footer.setText(getFooterText(tweet));
-
-        ColoredRelativeLayout typedView = (ColoredRelativeLayout) convertView;
-        if (tweet.isRetweet()) {
-            typedView.setHighlight(2);
-        } else if (tweet.getOriginalTweet().getMentions().contains(Application.getCurrentWorld().getAccount().getUser().getScreenName())) {
-            typedView.setHighlight(1);
-        } else {
-            typedView.setHighlight(0);
-        }
-    }
-
-    private static void updateViewFavorited(Tweet tweet, View convertView) {
-        ImageView favorited = (ImageView) convertView.findViewById(R.id.imageview_status_favorited);
-        favorited.setVisibility(tweet.isFavoritedBy(Application.getCurrentWorld().getAccount().getUserId()) ? View.VISIBLE : View.GONE);
-    }
-
-    private static void onIconClick(Tweet tweet, Activity activity) {
-        UserDetailDialogFragment dialogFragment = new UserDetailDialogFragment();
-        dialogFragment.setUserID(tweet.getOriginalTweet().getUser().getId());
-        DialogHelper.showDialog(activity, dialogFragment);
-    }
-
-    private static String getFooterText(Tweet tweet) {
-        StringBuilder builder = new StringBuilder();
-        if (tweet.isRetweet()) {
-            builder
-                    .append("(RT: ")
-                    .append(tweet.getUser().getScreenName())
-                    .append(") ");
-        }
-        builder.append(StringUtils.dateToString(tweet.getOriginalTweet().getCreatedAt()));
-        builder.append(" via ");
-        builder.append(Html.fromHtml(tweet.getOriginalTweet().getSource()));
-        return builder.toString();
-    }
-    
-    public static View getDirectMessageView(DirectMessage directMessage, Activity activity, View convertView) {
-        if (convertView == null) {
-            convertView = activity.getLayoutInflater().inflate(R.layout.list_item_status, null);
-        }
-        UIObserverBundle bundle = (UIObserverBundle) convertView.getTag();
-        if (bundle != null) {
-            bundle.detachAll();
-        } else {
-            bundle = new UIObserverBundle();
-            convertView.setTag(bundle);
-        }
-
-        convertView.setOnClickListener(new ListItemClickListener(activity, () -> DialogHelper.showDialog(activity, MessageDetailDialogFragment.newInstance(directMessage))));
-
-        ImageView favorited = (ImageView) convertView.findViewById(R.id.imageview_status_favorited);
-        favorited.setVisibility(View.GONE);
-
-        updateViewSender(directMessage, activity, convertView);
-        updateViewBody(directMessage, activity, convertView);
-
-        final WeakReference<View> weakView = new WeakReference<>(convertView);
-        final WeakReference<MainActivity> weakActivity = new WeakReference<>((MainActivity) activity);
-        bundle.attach(directMessage.getSender(), changes -> {
-            View strongView = weakView.get();
-            MainActivity strongActivity = weakActivity.get();
-            if (strongView != null && strongActivity != null && changes.contains(RBinding.BASIC))
-                updateViewSender(directMessage, strongActivity, strongView);
-        });
-
-        return convertView;
-    }
-
-    private static String getFooterText(DirectMessage directMessage, Account account) {
-        StringBuilder builder = new StringBuilder();
-        builder.append(StringUtils.dateToString(directMessage.getCreatedAt()));
-        if (directMessage.getSender().getId() == account.getUserId()) {
-            builder.append(" to @").append(directMessage.getRecipient().getScreenName());
-        }
-        return builder.toString();
-    }
-
-    private static void updateViewSender(DirectMessage directMessage, Activity activity, View convertView) {
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-
-        NetworkImageView icon = (NetworkImageView) convertView.findViewById(R.id.imageview_status_icon);
-        String iconUrl = directMessage.getSender().getProfileImageUrlOriginal();
-        icon.setImageUrl(iconUrl, ImageCache.getImageLoader());
-        icon.setOnClickListener(v -> {
-            UserDetailDialogFragment dialogFragment = new UserDetailDialogFragment();
-            dialogFragment.setUserID(directMessage.getSender().getId());
-            DialogHelper.showDialog(activity, dialogFragment);
-        });
-
-        TextView header = (TextView) convertView.findViewById(R.id.textview_status_header);
-        header.setTextSize(textSize);
-        header.setText(directMessage.getSender().getFormattedName());
-
-        ((ColoredRelativeLayout) convertView).setAccentVisibility(directMessage.getSender() == Application.getCurrentWorld().getAccount().getUser());
-    }
-
-    private static void updateViewBody(DirectMessage directMessage, Activity activity, View convertView) {
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-
-        TextView content = (TextView) convertView.findViewById(R.id.textview_status_text);
-        content.setTextSize(textSize);
-        content.setText(directMessage.getText());
-        TextView footer = (TextView) convertView.findViewById(R.id.textview_status_footer);
-        footer.setTextSize(textSize - 2);
-        footer.setText(getFooterText(directMessage, Application.getCurrentWorld().getAccount()));
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/Partials.kt b/app/src/main/java/net/lacolaco/smileessence/view/Partials.kt
new file mode 100644
index 00000000..27d8c3cd
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/Partials.kt
@@ -0,0 +1,220 @@
+package net.lacolaco.smileessence.view
+
+import android.app.Activity
+import android.text.Html
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageView
+import android.widget.ListView
+import android.widget.TextView
+import com.android.volley.toolbox.NetworkImageView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.data.ImageCache
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.entity.RBinding
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.util.StringUtils
+import net.lacolaco.smileessence.util.UIObserverBundle
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+import net.lacolaco.smileessence.view.dialog.MessageDetailDialogFragment
+import net.lacolaco.smileessence.view.dialog.StatusDetailDialogFragment
+import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment
+import net.lacolaco.smileessence.view.listener.ListItemClickListener
+
+import java.lang.ref.WeakReference
+import java.util.ArrayList
+
+object Partials {
+    fun getTweetView(tweet: Tweet, activity: Activity, convertView: View?, expandEmbeddedTweets: Boolean): View {
+        var convertView: View = convertView ?: activity.layoutInflater.inflate(R.layout.list_item_status, null)
+        var bundle: UIObserverBundle? = convertView.tag as UIObserverBundle?
+        if (bundle != null) {
+            bundle.detachAll()
+        } else {
+            bundle = UIObserverBundle()
+            convertView.tag = bundle
+        }
+
+        convertView.setOnClickListener(ListItemClickListener(activity) { DialogHelper.showDialog(activity, StatusDetailDialogFragment.newInstance(tweet)) })
+
+        updateViewUser(tweet, activity, convertView)
+        updateViewBody(tweet, activity, convertView)
+        updateViewFavorited(tweet, convertView)
+        updateViewEmbeddeds(tweet, activity, convertView, expandEmbeddedTweets)
+
+        val weakView = WeakReference(convertView)
+        val weakActivity = WeakReference(activity)
+        bundle.attach(tweet.originalTweet) { changes ->
+            val strongView = weakView.get()
+            if (strongView != null && changes.contains(RBinding.FAVORITERS))
+                updateViewFavorited(tweet, strongView)
+        }
+        bundle.attach(tweet.user) { changes ->
+            val strongView = weakView.get()
+            val strongActivity = weakActivity.get()
+            if (strongView != null && strongActivity != null && changes.contains(RBinding.BASIC))
+                updateViewUser(tweet, strongActivity, strongView)
+        }
+
+        return convertView
+    }
+
+
+    private fun updateViewEmbeddeds(tweet: Tweet, activity: Activity, convertView: View, expandEmbeddedTweets: Boolean) {
+        val embeddedStatus = convertView.findViewById(R.id.listview_status_embedded_status) as ListView
+        if (expandEmbeddedTweets) {
+            val list = ArrayList<Tweet>()
+            val embeddedTweetsAdapter = object : CustomListAdapter<Tweet>() {
+                override val list: List<Tweet>
+                    get() = list
+
+                override fun getView(position: Int, convertView: View, parent: ViewGroup): View {
+                    return Partials.getTweetView(getItem(position), activity, convertView, false)
+                }
+            }
+
+            val account = Application.currentWorld!!.account
+            for (id in tweet.embeddedStatusIDs) {
+                Tweet.fetchTask(id, account).onDone { t -> list.add(t) }.execute()
+            }
+            embeddedStatus.adapter = embeddedTweetsAdapter
+            embeddedStatus.visibility = View.VISIBLE
+        } else {
+            embeddedStatus.adapter = null // view may be reused, set null explicitly
+            embeddedStatus.visibility = View.GONE
+        }
+    }
+
+    private fun updateViewUser(tweet: Tweet, activity: Activity, convertView: View) {
+        val textSize = UserPreferenceHelper.instance.textSize
+
+        val icon = convertView.findViewById(R.id.imageview_status_icon) as NetworkImageView
+        val iconUrl = tweet.originalTweet.user.profileImageUrl
+        icon.setImageUrl(iconUrl, ImageCache.getImageLoader())
+        icon.setOnClickListener { v -> onIconClick(tweet, activity) }
+
+        val header = convertView.findViewById(R.id.textview_status_header) as TextView
+        header.textSize = textSize.toFloat()
+        header.text = tweet.originalTweet.user.formattedName
+
+        (convertView as ColoredRelativeLayout).setAccentVisibility(tweet.user === Application.currentWorld!!.account.user)
+    }
+
+    private fun updateViewBody(tweet: Tweet, activity: Activity, convertView: View) {
+        val textSize = UserPreferenceHelper.instance.textSize
+
+        val content = convertView.findViewById(R.id.textview_status_text) as TextView
+        content.textSize = textSize.toFloat()
+        val rawText = tweet.originalTweet.text
+        content.text = rawText
+        val footer = convertView.findViewById(R.id.textview_status_footer) as TextView
+        footer.textSize = (textSize - 2).toFloat()
+        footer.text = getFooterText(tweet)
+
+        val typedView = convertView as ColoredRelativeLayout
+        if (tweet.isRetweet) {
+            typedView.setHighlight(2)
+        } else if (tweet.originalTweet.mentions.contains(Application.currentWorld!!.account.user.screenName)) {
+            typedView.setHighlight(1)
+        } else {
+            typedView.setHighlight(0)
+        }
+    }
+
+    private fun updateViewFavorited(tweet: Tweet, convertView: View) {
+        val favorited = convertView.findViewById(R.id.imageview_status_favorited) as ImageView
+        favorited.visibility = if (tweet.isFavoritedBy(Application.currentWorld!!.account.userId)) View.VISIBLE else View.GONE
+    }
+
+    private fun onIconClick(tweet: Tweet, activity: Activity) {
+        DialogHelper.showDialog(activity, UserDetailDialogFragment.newInstance(tweet.originalTweet.user))
+    }
+
+    private fun getFooterText(tweet: Tweet): String {
+        val builder = StringBuilder()
+        if (tweet.isRetweet) {
+            builder
+                    .append("(RT: ")
+                    .append(tweet.user.screenName)
+                    .append(") ")
+        }
+        builder.append(StringUtils.dateToString(tweet.originalTweet.createdAt))
+        builder.append(" via ")
+        builder.append(Html.fromHtml(tweet.originalTweet.source))
+        return builder.toString()
+    }
+
+    fun getDirectMessageView(directMessage: DirectMessage, activity: Activity, convertView: View?): View {
+        var convertView = convertView
+        if (convertView == null) {
+            convertView = activity.layoutInflater.inflate(R.layout.list_item_status, null)
+        }
+        var bundle: UIObserverBundle? = convertView!!.tag as UIObserverBundle?
+        if (bundle != null) {
+            bundle.detachAll()
+        } else {
+            bundle = UIObserverBundle()
+            convertView.tag = bundle
+        }
+
+        convertView.setOnClickListener(ListItemClickListener(activity) { DialogHelper.showDialog(activity, MessageDetailDialogFragment.newInstance(directMessage)) })
+
+        val favorited = convertView.findViewById(R.id.imageview_status_favorited) as ImageView
+        favorited.visibility = View.GONE
+
+        updateViewSender(directMessage, activity, convertView)
+        updateViewBody(directMessage, activity, convertView)
+
+        val weakView = WeakReference(convertView)
+        val weakActivity = WeakReference(activity as MainActivity)
+        bundle.attach(directMessage.sender) { changes ->
+            val strongView = weakView.get()
+            val strongActivity = weakActivity.get()
+            if (strongView != null && strongActivity != null && changes.contains(RBinding.BASIC))
+                updateViewSender(directMessage, strongActivity, strongView)
+        }
+
+        return convertView
+    }
+
+    private fun getFooterText(directMessage: DirectMessage, account: Account): String {
+        val builder = StringBuilder()
+        builder.append(StringUtils.dateToString(directMessage.createdAt))
+        if (directMessage.sender.id == account.userId) {
+            builder.append(" to @").append(directMessage.recipient.screenName)
+        }
+        return builder.toString()
+    }
+
+    private fun updateViewSender(directMessage: DirectMessage, activity: Activity, convertView: View) {
+        val textSize = UserPreferenceHelper.instance.textSize
+
+        val icon = convertView.findViewById(R.id.imageview_status_icon) as NetworkImageView
+        val iconUrl = directMessage.sender.profileImageUrl
+        icon.setImageUrl(iconUrl, ImageCache.getImageLoader())
+        icon.setOnClickListener { v ->
+            DialogHelper.showDialog(activity, UserDetailDialogFragment.newInstance(directMessage.sender))
+        }
+
+        val header = convertView.findViewById(R.id.textview_status_header) as TextView
+        header.textSize = textSize.toFloat()
+        header.text = directMessage.sender.formattedName
+
+        (convertView as ColoredRelativeLayout).setAccentVisibility(directMessage.sender === Application.currentWorld!!.account.user)
+    }
+
+    private fun updateViewBody(directMessage: DirectMessage, activity: Activity, convertView: View) {
+        val textSize = UserPreferenceHelper.instance.textSize
+
+        val content = convertView.findViewById(R.id.textview_status_text) as TextView
+        content.textSize = textSize.toFloat()
+        content.text = directMessage.text
+        val footer = convertView.findViewById(R.id.textview_status_footer) as TextView
+        footer.textSize = (textSize - 2).toFloat()
+        footer.text = getFooterText(directMessage, Application.currentWorld!!.account)
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.java
deleted file mode 100644
index 7ed9636b..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.java
+++ /dev/null
@@ -1,147 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view;
-
-import android.app.AlertDialog;
-import android.content.Intent;
-import android.content.SharedPreferences;
-import android.os.Bundle;
-import android.preference.EditTextPreference;
-import android.preference.ListPreference;
-import android.preference.Preference;
-import android.preference.PreferenceFragment;
-import android.text.TextUtils;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.widget.TextView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.BuildConfig;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.LicenseActivity;
-
-import static android.content.SharedPreferences.OnSharedPreferenceChangeListener;
-
-public class SettingFragment extends PreferenceFragment implements OnSharedPreferenceChangeListener,
-        Preference.OnPreferenceChangeListener, Preference.OnPreferenceClickListener {
-    @Override
-    public boolean onPreferenceChange(Preference preference, Object newValue) {
-        String newValueStr = String.valueOf(newValue);
-        if (preference.getKey().contentEquals(getString(R.string.key_setting_text_size))) {
-            if (TextUtils.isDigitsOnly(newValueStr)) {
-                return true;
-            } else {
-                Application.toast(R.string.error_setting_text_size_not_number);
-            }
-            return false;
-        } else if (preference.getKey().contentEquals(getString(R.string.key_setting_theme))) {
-            Application.toast(R.string.notice_theme_changed);
-        }
-        return true;
-    }
-
-    // --------------------- Interface OnPreferenceClickListener ---------------------
-
-    @Override
-    public boolean onPreferenceClick(Preference preference) {
-        String key = preference.getKey();
-        if (key.contentEquals(getString(R.string.key_setting_application_information))) {
-            openAppInfoDialog();
-        } else if (key.contentEquals(getString(R.string.key_setting_licenses))) {
-            openLicenseActivity();
-        }
-        return true;
-    }
-
-    // --------------------- Interface OnSharedPreferenceChangeListener ---------------------
-
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-        setSummaryCurrentValue();
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        addPreferencesFromResource(R.xml.setting);
-        EditTextPreference textSizePreference = (EditTextPreference) findPreference(R.string.key_setting_text_size);
-        textSizePreference.setSummary(textSizePreference.getText());
-        textSizePreference.setOnPreferenceChangeListener(this);
-        ListPreference themePreference = (ListPreference) findPreference(R.string.key_setting_theme);
-        themePreference.setSummary(themePreference.getEntry());
-        themePreference.setOnPreferenceChangeListener(this);
-        Preference appInfoPreference = findPreference(R.string.key_setting_application_information);
-        appInfoPreference.setOnPreferenceClickListener(this);
-        appInfoPreference.setSummary(BuildConfig.VERSION_NAME + " (" + BuildConfig.VERSION_CODE + ")");
-        Preference license = findPreference(R.string.key_setting_licenses);
-        license.setOnPreferenceClickListener(this);
-    }
-
-    @Override
-    public void onPause() {
-        super.onPause();
-        SharedPreferences sharedPreferences = getPreferenceScreen().getSharedPreferences();
-        sharedPreferences.unregisterOnSharedPreferenceChangeListener(this);
-    }
-
-    @Override
-    public void onResume() {
-        super.onResume();
-        SharedPreferences sharedPreferences = getPreferenceScreen().getSharedPreferences();
-        sharedPreferences.registerOnSharedPreferenceChangeListener(this);
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    public Preference findPreference(int preferenceResID) {
-        return findPreference(getString(preferenceResID));
-    }
-
-    private void openLicenseActivity() {
-        Intent intent = new Intent(getActivity(), LicenseActivity.class);
-        getActivity().startActivity(intent);
-    }
-
-    private void openAppInfoDialog() {
-        LayoutInflater inflater = getActivity().getLayoutInflater();
-        View contentView = inflater.inflate(R.layout.dialog_app_info, null);
-        TextView versionTextView = (TextView) contentView.findViewById(R.id.versionTextView);
-        versionTextView.setText(BuildConfig.VERSION_NAME + " (rev: " + BuildConfig.VERSION_CODE + "; upstream: " + getString(R.string.app_version_full) + ")");
-
-        new AlertDialog.Builder(getActivity())
-                .setTitle(R.string.dialog_title_about)
-                .setView(contentView)
-                .setPositiveButton(R.string.alert_dialog_ok, (dialog, which) -> dialog.dismiss())
-                .create().show();
-    }
-
-    private void setSummaryCurrentValue() {
-        EditTextPreference textSizePreference = (EditTextPreference) findPreference(R.string.key_setting_text_size);
-        textSizePreference.setSummary(textSizePreference.getText());
-        ListPreference themePreference = (ListPreference) findPreference(R.string.key_setting_theme);
-        themePreference.setSummary(themePreference.getEntry());
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.kt
new file mode 100644
index 00000000..05490f97
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/SettingFragment.kt
@@ -0,0 +1,140 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view
+
+import android.app.AlertDialog
+import android.content.Intent
+import android.content.SharedPreferences
+import android.os.Bundle
+import android.preference.EditTextPreference
+import android.preference.ListPreference
+import android.preference.Preference
+import android.preference.PreferenceFragment
+import android.text.TextUtils
+import android.view.LayoutInflater
+import android.view.View
+import android.widget.TextView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.BuildConfig
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.LicenseActivity
+
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener
+
+class SettingFragment : PreferenceFragment(), OnSharedPreferenceChangeListener, Preference.OnPreferenceChangeListener, Preference.OnPreferenceClickListener {
+    override fun onPreferenceChange(preference: Preference, newValue: Any): Boolean {
+        val newValueStr = newValue.toString()
+        if (preference.key.contentEquals(getString(R.string.key_setting_text_size))) {
+            if (TextUtils.isDigitsOnly(newValueStr)) {
+                return true
+            } else {
+                Application.toast(R.string.error_setting_text_size_not_number)
+            }
+            return false
+        } else if (preference.key.contentEquals(getString(R.string.key_setting_theme))) {
+            Application.toast(R.string.notice_theme_changed)
+        }
+        return true
+    }
+
+    // --------------------- Interface OnPreferenceClickListener ---------------------
+
+    override fun onPreferenceClick(preference: Preference): Boolean {
+        val key = preference.key
+        if (key.contentEquals(getString(R.string.key_setting_application_information))) {
+            openAppInfoDialog()
+        } else if (key.contentEquals(getString(R.string.key_setting_licenses))) {
+            openLicenseActivity()
+        }
+        return true
+    }
+
+    // --------------------- Interface OnSharedPreferenceChangeListener ---------------------
+
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+        setSummaryCurrentValue()
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        addPreferencesFromResource(R.xml.setting)
+        val textSizePreference = findPreference(R.string.key_setting_text_size) as EditTextPreference
+        textSizePreference.summary = textSizePreference.text
+        textSizePreference.onPreferenceChangeListener = this
+        val themePreference = findPreference(R.string.key_setting_theme) as ListPreference
+        themePreference.summary = themePreference.entry
+        themePreference.onPreferenceChangeListener = this
+        val appInfoPreference = findPreference(R.string.key_setting_application_information)
+        appInfoPreference.onPreferenceClickListener = this
+        appInfoPreference.summary = BuildConfig.VERSION_NAME + " (" + BuildConfig.VERSION_CODE + ")"
+        val license = findPreference(R.string.key_setting_licenses)
+        license.onPreferenceClickListener = this
+    }
+
+    override fun onPause() {
+        super.onPause()
+        val sharedPreferences = preferenceScreen.sharedPreferences
+        sharedPreferences.unregisterOnSharedPreferenceChangeListener(this)
+    }
+
+    override fun onResume() {
+        super.onResume()
+        val sharedPreferences = preferenceScreen.sharedPreferences
+        sharedPreferences.registerOnSharedPreferenceChangeListener(this)
+    }
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    fun findPreference(preferenceResID: Int): Preference {
+        return findPreference(getString(preferenceResID))
+    }
+
+    private fun openLicenseActivity() {
+        val intent = Intent(activity, LicenseActivity::class.java)
+        activity.startActivity(intent)
+    }
+
+    private fun openAppInfoDialog() {
+        val inflater = activity.layoutInflater
+        val contentView = inflater.inflate(R.layout.dialog_app_info, null)
+        val versionTextView = contentView.findViewById(R.id.versionTextView) as TextView
+        versionTextView.text = BuildConfig.VERSION_NAME + " (rev: " + BuildConfig.VERSION_CODE + "; upstream: " + getString(R.string.app_version_full) + ")"
+
+        AlertDialog.Builder(activity)
+                .setTitle(R.string.dialog_title_about)
+                .setView(contentView)
+                .setPositiveButton(R.string.alert_dialog_ok) { dialog, which -> dialog.dismiss() }
+                .create().show()
+    }
+
+    private fun setSummaryCurrentValue() {
+        val textSizePreference = findPreference(R.string.key_setting_text_size) as EditTextPreference
+        textSizePreference.summary = textSizePreference.text
+        val themePreference = findPreference(R.string.key_setting_theme) as ListPreference
+        themePreference.summary = themePreference.entry
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.java b/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.java
deleted file mode 100644
index d5358db5..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package net.lacolaco.smileessence.view;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.graphics.drawable.Drawable;
-import android.util.AttributeSet;
-import android.widget.Button;
-import net.lacolaco.smileessence.R;
-
-public class ThreeStateButton extends Button {
-    public static final int STATE_OFF = 0;
-    public static final int STATE_ON = 1;
-    public static final int STATE_LOCKED = 2;
-
-    private int state = STATE_OFF;
-    private String texts[] = new String[3];
-    private Drawable backgrounds[] = new Drawable[3];
-
-    public ThreeStateButton(Context context) {
-        this(context, null);
-    }
-
-    public ThreeStateButton(Context context, AttributeSet attrs) {
-        this(context, attrs, android.R.attr.buttonStyle);
-    }
-
-    public ThreeStateButton(Context context, AttributeSet attrs, int defStyleAttr) {
-        this(context, attrs, defStyleAttr, 0);
-    }
-
-    public ThreeStateButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
-
-        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ThreeStateButton);
-        texts[STATE_OFF] = ta.getString(R.styleable.ThreeStateButton_off_text);
-        texts[STATE_ON] = ta.getString(R.styleable.ThreeStateButton_on_text);
-        texts[STATE_LOCKED] = ta.getString(R.styleable.ThreeStateButton_locked_text);
-        backgrounds[STATE_OFF] = ta.getDrawable(R.styleable.ThreeStateButton_off_background);
-        backgrounds[STATE_ON] = ta.getDrawable(R.styleable.ThreeStateButton_on_background);
-        backgrounds[STATE_LOCKED] = ta.getDrawable(R.styleable.ThreeStateButton_locked_background);
-        ta.recycle();
-
-        setState(STATE_OFF);
-    }
-
-    public int getState() {
-        return state;
-    }
-
-    public void setState(int s) {
-        state = s;
-        setText(texts[state]);
-        setBackground(backgrounds[state]);
-        setEnabled(state != STATE_LOCKED);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.kt b/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.kt
new file mode 100644
index 00000000..547aa84d
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/ThreeStateButton.kt
@@ -0,0 +1,41 @@
+package net.lacolaco.smileessence.view
+
+import android.content.Context
+import android.content.res.TypedArray
+import android.graphics.drawable.Drawable
+import android.util.AttributeSet
+import android.widget.Button
+import net.lacolaco.smileessence.R
+
+class ThreeStateButton @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = android.R.attr.buttonStyle, defStyleRes: Int = 0) : Button(context, attrs, defStyleAttr, defStyleRes) {
+
+    var state = STATE_OFF
+        set(s) {
+            field = s
+            text = texts[this.state]
+            background = backgrounds[this.state]
+            isEnabled = this.state != STATE_LOCKED
+        }
+    private val texts = arrayOfNulls<String>(3)
+    private val backgrounds = arrayOfNulls<Drawable>(3)
+
+    init {
+
+        val ta = context.obtainStyledAttributes(attrs, R.styleable.ThreeStateButton)
+        texts[STATE_OFF] = ta.getString(R.styleable.ThreeStateButton_off_text)
+        texts[STATE_ON] = ta.getString(R.styleable.ThreeStateButton_on_text)
+        texts[STATE_LOCKED] = ta.getString(R.styleable.ThreeStateButton_locked_text)
+        backgrounds[STATE_OFF] = ta.getDrawable(R.styleable.ThreeStateButton_off_background)
+        backgrounds[STATE_ON] = ta.getDrawable(R.styleable.ThreeStateButton_on_background)
+        backgrounds[STATE_LOCKED] = ta.getDrawable(R.styleable.ThreeStateButton_locked_background)
+        ta.recycle()
+
+        state = STATE_OFF
+    }
+
+    companion object {
+        val STATE_OFF = 0
+        val STATE_ON = 1
+        val STATE_LOCKED = 2
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.java b/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.java
deleted file mode 100644
index b7b2d174..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package net.lacolaco.smileessence.view;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.graphics.drawable.Drawable;
-import android.util.AttributeSet;
-import android.widget.ImageButton;
-import net.lacolaco.smileessence.R;
-
-public class ToggleableImageButton extends ImageButton {
-    private Drawable onSrc, offSrc;
-
-    public ToggleableImageButton(Context context) {
-        this(context, null);
-    }
-
-    public ToggleableImageButton(Context context, AttributeSet attrs) {
-        this(context, attrs, android.R.attr.imageButtonStyle);
-    }
-
-    public ToggleableImageButton(Context context, AttributeSet attrs, int defStyleAttr) {
-        this(context, attrs, defStyleAttr, 0);
-    }
-
-    public ToggleableImageButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
-
-        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ToggleableImageButton);
-        offSrc = ta.getDrawable(R.styleable.ToggleableImageButton_offSrc);
-        onSrc = ta.getDrawable(R.styleable.ToggleableImageButton_onSrc);
-        ta.recycle();
-    }
-
-    public void setState(boolean isOn) {
-        setImageDrawable(isOn ? onSrc : offSrc);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.kt b/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.kt
new file mode 100644
index 00000000..47a1821a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/ToggleableImageButton.kt
@@ -0,0 +1,25 @@
+package net.lacolaco.smileessence.view
+
+import android.content.Context
+import android.content.res.TypedArray
+import android.graphics.drawable.Drawable
+import android.util.AttributeSet
+import android.widget.ImageButton
+import net.lacolaco.smileessence.R
+
+class ToggleableImageButton @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = android.R.attr.imageButtonStyle, defStyleRes: Int = 0) : ImageButton(context, attrs, defStyleAttr, defStyleRes) {
+    private val onSrc: Drawable
+    private val offSrc: Drawable
+
+    init {
+
+        val ta = context.obtainStyledAttributes(attrs, R.styleable.ToggleableImageButton)
+        offSrc = ta.getDrawable(R.styleable.ToggleableImageButton_offSrc)
+        onSrc = ta.getDrawable(R.styleable.ToggleableImageButton_onSrc)
+        ta.recycle()
+    }
+
+    fun setState(isOn: Boolean) {
+        setImageDrawable(if (isOn) onSrc else offSrc)
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.java
deleted file mode 100644
index 6d7420fb..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.java
+++ /dev/null
@@ -1,50 +0,0 @@
-package net.lacolaco.smileessence.view.adapter;
-
-import android.widget.BaseAdapter;
-import net.lacolaco.smileessence.util.UIHandler;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-public abstract class CustomListAdapter<T> extends BaseAdapter {
-    private boolean isNotifiable = true;
-    private List<T> frozenList = new ArrayList<>();
-
-    public final void setNotifiable(boolean notifiable) {
-        isNotifiable = notifiable;
-    }
-
-    @Override
-    public final int getCount() {
-        return frozenList.size();
-    }
-
-    @Override
-    public final T getItem(int position) {
-        return frozenList.get(position);
-    }
-
-    @Override
-    public long getItemId(int position) {
-        return position;
-    }
-
-    @Override
-    public final void notifyDataSetChanged() {
-        frozenList = Collections.unmodifiableList(getList());
-        super.notifyDataSetChanged();
-    }
-
-    protected abstract List<T> getList();
-
-    public void update() {
-        if (isNotifiable) {
-            updateForce();
-        }
-    }
-
-    public void updateForce() {
-        new UIHandler().post(this::notifyDataSetChanged);
-    }
-}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.kt
new file mode 100644
index 00000000..3b022012
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/CustomListAdapter.kt
@@ -0,0 +1,45 @@
+package net.lacolaco.smileessence.view.adapter
+
+import android.widget.BaseAdapter
+import net.lacolaco.smileessence.util.UIHandler
+
+import java.util.ArrayList
+import java.util.Collections
+
+abstract class CustomListAdapter<T> : BaseAdapter() {
+    private var isNotifiable = true
+    private var frozenList: List<T> = ArrayList()
+
+    fun setNotifiable(notifiable: Boolean) {
+        isNotifiable = notifiable
+    }
+
+    override fun getCount(): Int {
+        return frozenList.size
+    }
+
+    override fun getItem(position: Int): T {
+        return frozenList[position]
+    }
+
+    override fun getItemId(position: Int): Long {
+        return position.toLong()
+    }
+
+    override fun notifyDataSetChanged() {
+        frozenList = Collections.unmodifiableList(list)
+        super.notifyDataSetChanged()
+    }
+
+    protected abstract val list: List<T>
+
+    fun update() {
+        if (isNotifiable) {
+            updateForce()
+        }
+    }
+
+    fun updateForce() {
+        UIHandler().post { this.notifyDataSetChanged() }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.java
deleted file mode 100644
index 3f98cfaa..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.java
+++ /dev/null
@@ -1,116 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.adapter;
-
-import android.app.Activity;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ImageView;
-import android.widget.TextView;
-import com.android.volley.toolbox.NetworkImageView;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.data.ImageCache;
-import net.lacolaco.smileessence.entity.Event;
-import net.lacolaco.smileessence.entity.RBinding;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.util.StringUtils;
-import net.lacolaco.smileessence.util.UIObserverBundle;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment;
-import net.lacolaco.smileessence.view.listener.ListItemClickListener;
-
-import java.lang.ref.WeakReference;
-import java.util.List;
-
-public class EventListAdapter extends CustomListAdapter<Event> {
-    private final World world;
-    private final Activity activity;
-
-    public EventListAdapter(World world, Activity activity) {
-        super();
-        this.world = world;
-        this.activity = activity;
-    }
-
-    @Override
-    protected List<Event> getList() {
-        return world.getEvents();
-    }
-
-    @Override
-    public View getView(int position, View convertView, ViewGroup parent) {
-        Event event = getItem(position);
-        if (convertView == null) {
-            convertView = activity.getLayoutInflater().inflate(R.layout.list_item_status, null);
-        }
-        UIObserverBundle bundle = (UIObserverBundle) convertView.getTag();
-        if (bundle != null) {
-            bundle.detachAll();
-        } else {
-            bundle = new UIObserverBundle();
-            convertView.setTag(bundle);
-        }
-
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-
-        TextView header = (TextView) convertView.findViewById(R.id.textview_status_header);
-        header.setTextSize(textSize);
-
-        updateViewUser(event, convertView);
-
-        TextView content = (TextView) convertView.findViewById(R.id.textview_status_text);
-        content.setTextSize(textSize);
-        content.setText(event.getTargetObject() != null ? event.getTargetObject().getText() : "");
-        TextView footer = (TextView) convertView.findViewById(R.id.textview_status_footer);
-        footer.setTextSize(textSize - 2);
-        footer.setText(StringUtils.dateToString(event.getCreatedAt()));
-        ImageView favorited = (ImageView) convertView.findViewById(R.id.imageview_status_favorited);
-        favorited.setVisibility(View.GONE);
-        convertView.setOnClickListener(new ListItemClickListener(activity, () -> {
-            UserDetailDialogFragment fragment = new UserDetailDialogFragment();
-            fragment.setUserID(event.getSource().getId());
-            DialogHelper.showDialog(activity, fragment);
-        }));
-
-        final WeakReference<View> weakView = new WeakReference<>(convertView);
-        bundle.attach(event.getSource(), changes -> {
-            View strongView = weakView.get();
-            if (strongView != null && changes.contains(RBinding.BASIC))
-                updateViewUser(event, strongView);
-        });
-
-        return convertView;
-    }
-
-    private void updateViewUser(Event event, View convertedView) {
-        NetworkImageView icon = (NetworkImageView) convertedView.findViewById(R.id.imageview_status_icon);
-        String iconUrl = event.getSource().getProfileImageUrlOriginal();
-        icon.setImageUrl(iconUrl, ImageCache.getImageLoader());
-
-        TextView header = (TextView) convertedView.findViewById(R.id.textview_status_header);
-        header.setText(event.getFormattedString());
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.kt
new file mode 100644
index 00000000..1c19d4ec
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/EventListAdapter.kt
@@ -0,0 +1,102 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.adapter
+
+import android.app.Activity
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageView
+import android.widget.TextView
+import com.android.volley.toolbox.NetworkImageView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.data.ImageCache
+import net.lacolaco.smileessence.entity.Event
+import net.lacolaco.smileessence.entity.RBinding
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.util.StringUtils
+import net.lacolaco.smileessence.util.UIObserverBundle
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment
+import net.lacolaco.smileessence.view.listener.ListItemClickListener
+
+import java.lang.ref.WeakReference
+
+class EventListAdapter(private val world: World, private val activity: Activity) : CustomListAdapter<Event>() {
+    override val list: List<Event>
+        get() = world.events
+
+    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+        var convertView = convertView
+        val event = getItem(position)
+        if (convertView == null) {
+            convertView = activity.layoutInflater.inflate(R.layout.list_item_status, null)
+        }
+        var bundle: UIObserverBundle? = convertView!!.tag as UIObserverBundle?
+        if (bundle != null) {
+            bundle.detachAll()
+        } else {
+            bundle = UIObserverBundle()
+            convertView.tag = bundle
+        }
+
+        val textSize = UserPreferenceHelper.instance.textSize
+
+        val header = convertView.findViewById(R.id.textview_status_header) as TextView
+        header.textSize = textSize.toFloat()
+
+        updateViewUser(event, convertView)
+
+        val content = convertView.findViewById(R.id.textview_status_text) as TextView
+        content.textSize = textSize.toFloat()
+        content.text = event.targetObject?.text ?: ""
+        val footer = convertView.findViewById(R.id.textview_status_footer) as TextView
+        footer.textSize = (textSize - 2).toFloat()
+        footer.text = StringUtils.dateToString(event.createdAt)
+        val favorited = convertView.findViewById(R.id.imageview_status_favorited) as ImageView
+        favorited.visibility = View.GONE
+        convertView.setOnClickListener(ListItemClickListener(activity) {
+            DialogHelper.showDialog(activity, UserDetailDialogFragment.newInstance(event.source))
+        })
+
+        val weakView = WeakReference(convertView)
+        bundle.attach(event.source) { changes ->
+            val strongView = weakView.get()
+            if (strongView != null && changes.contains(RBinding.BASIC))
+                updateViewUser(event, strongView)
+        }
+
+        return convertView
+    }
+
+    private fun updateViewUser(event: Event, convertedView: View) {
+        val icon = convertedView.findViewById(R.id.imageview_status_icon) as NetworkImageView
+        val iconUrl = event.source.profileImageUrl
+        icon.setImageUrl(iconUrl, ImageCache.getImageLoader())
+
+        val header = convertedView.findViewById(R.id.textview_status_header) as TextView
+        header.text = event.formattedString
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.java
deleted file mode 100644
index 9f8e5039..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.adapter;
-
-import android.app.Activity;
-import android.view.View;
-import android.view.ViewGroup;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.view.Partials;
-
-public class MessageListAdapter extends OrderedCustomListAdapter<DirectMessage> {
-    private final Activity activity;
-
-    public MessageListAdapter(Activity activity) {
-        super();
-        this.activity = activity;
-    }
-
-    public long getLastID() {
-        return getCount() > 0 ? getItem(getCount() - 1).getId() : -1;
-    }
-
-    public long getTopID() {
-        return getCount() > 0 ? getItem(0).getId() : -1;
-    }
-
-    @Override
-    public View getView(int position, View convertView, ViewGroup parent) {
-        return Partials.getDirectMessageView(getItem(position), activity, convertView);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.kt
new file mode 100644
index 00000000..d72ab564
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/MessageListAdapter.kt
@@ -0,0 +1,43 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.adapter
+
+import android.app.Activity
+import android.view.View
+import android.view.ViewGroup
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.view.Partials
+
+class MessageListAdapter(private val activity: Activity) : OrderedCustomListAdapter<DirectMessage>() {
+    val lastID: Long
+        get() = if (count > 0) getItem(count - 1).id else -1
+
+    val topID: Long
+        get() = if (count > 0) getItem(0).id else -1
+
+    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+        return Partials.getDirectMessageView(getItem(position), activity, convertView)
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.java
deleted file mode 100644
index 3de58658..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package net.lacolaco.smileessence.view.adapter;
-
-import net.lacolaco.smileessence.entity.IdObject;
-
-import java.util.*;
-
-public abstract class OrderedCustomListAdapter<T extends IdObject> extends CustomListAdapter<T> {
-    private final Map<Long, T> treeMap;
-
-    public OrderedCustomListAdapter() {
-        this(Long::compare);
-    }
-
-    public OrderedCustomListAdapter(Comparator<Long> comparator) {
-        super();
-        this.treeMap = new TreeMap<>(Collections.reverseOrder(comparator));
-    }
-
-    @Override
-    protected synchronized List<T> getList() {
-        return new ArrayList<>(treeMap.values());
-    }
-
-    public synchronized void add(T item) {
-        treeMap.put(item.getId(), item);
-    }
-
-    public synchronized void addAll(Collection<T> items) {
-        for (T item : items) {
-            treeMap.put(item.getId(), item);
-        }
-    }
-
-    public synchronized void clear() {
-        treeMap.clear();
-    }
-
-    public synchronized T remove(T item) {
-        return treeMap.remove(item.getId());
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.kt
new file mode 100644
index 00000000..53b1c824
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/OrderedCustomListAdapter.kt
@@ -0,0 +1,35 @@
+package net.lacolaco.smileessence.view.adapter
+
+import net.lacolaco.smileessence.entity.IdObject
+
+import java.util.*
+
+abstract class OrderedCustomListAdapter<T : IdObject>
+constructor(comparator: Comparator<Long> = Comparator { x, y -> java.lang.Long.compare(x, y) }) : CustomListAdapter<T>() {
+    private val treeMap: MutableMap<Long, T> = TreeMap(Collections.reverseOrder(comparator))
+
+    override val list: List<T>
+        @Synchronized get() = ArrayList(treeMap.values)
+
+    @Synchronized
+    fun add(item: T) {
+        treeMap.put(item.id, item)
+    }
+
+    @Synchronized
+    fun addAll(items: Collection<T>) {
+        for (item in items) {
+            treeMap.put(item.id, item)
+        }
+    }
+
+    @Synchronized
+    fun clear() {
+        treeMap.clear()
+    }
+
+    @Synchronized
+    fun remove(item: T): T {
+        return treeMap.remove(item.id)!!
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.java
deleted file mode 100644
index 76e72093..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.java
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.adapter;
-
-import android.os.Bundle;
-import android.support.v13.app.FragmentPagerAdapter;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.view.page.PageFragment;
-
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-public class PageListAdapter extends FragmentPagerAdapter {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private final List<PageInfo> pages = new ArrayList<>();
-    private final Map<Integer, WeakReference<PageFragment>> fragmentCache = new HashMap<>();
-
-    // --------------------------- FragmentPagerAdapter ---------------------------
-
-    public PageListAdapter(MainActivity _activity) {
-        super(_activity.getFragmentManager());
-    }
-
-    @Override
-    public synchronized PageFragment getItem(int position) {
-        PageFragment pf;
-        PageInfo info = pages.get(position);
-        try {
-            pf = info.getFragmentClass().newInstance();
-        } catch (Exception e) {
-            Logger.error("should not happen: fragmentClass is private or Android is broken?");
-            e.printStackTrace();
-            throw new RuntimeException(e);
-        }
-        pf.setArguments(info.getArgs());
-        fragmentCache.put(position, new WeakReference<>(pf));
-        return pf;
-    }
-
-    public synchronized PageFragment getCachedFragment(int pos) {
-        WeakReference<PageFragment> wpf = fragmentCache.get(pos);
-        if (wpf == null) {
-            return null;
-        } else {
-            return wpf.get();
-        }
-    }
-
-    @Override
-    public synchronized int getCount() {
-        return pages.size();
-    }
-
-    // ------------------------ INTERFACE METHODS ------------------------
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    public void addPage(Class<? extends PageFragment> klass, String name, Bundle args) {
-        this.addPage(klass, name, args, true);
-    }
-
-    public void addPage(Class<? extends PageFragment> klass, String name, Bundle args, boolean notifyChanged) {
-        pages.add(new PageInfo(klass, name, args));
-        if (notifyChanged) notifyDataSetChanged();
-    }
-
-    public synchronized boolean removePage(int position) {
-        //if (removePageWithoutNotify(position)) {
-        //    refreshListNavigation();
-        //    return true;
-        //}
-        return pages.remove(position) != null; // TODO
-    }
-
-    public String getName(int pos) {
-        return pages.get(pos).getName();
-    }
-
-    @Deprecated
-    public int getIndex(Class<? extends PageFragment> fragmentClass) {
-        for (int i = 0; i < pages.size(); ++i) {
-            if (pages.get(i).getFragmentClass() == fragmentClass) {
-                return i;
-            }
-        }
-        return -1;
-    }
-
-    private static final class PageInfo {
-        private final Class<? extends PageFragment> fragmentClass;
-        private final Bundle args;
-        private final String name;
-
-        PageInfo(Class<? extends PageFragment> _fragmentClass, String _name, Bundle _args) {
-            fragmentClass = _fragmentClass;
-            name = _name;
-            args = _args;
-        }
-
-        public Class<? extends PageFragment> getFragmentClass() {
-            return fragmentClass;
-        }
-
-        public String getName() {
-            return name;
-        }
-
-        public Bundle getArgs() {
-            return args;
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.kt
new file mode 100644
index 00000000..34d158f0
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.kt
@@ -0,0 +1,110 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.adapter
+
+import android.os.Bundle
+import android.support.v13.app.FragmentPagerAdapter
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.view.page.PageFragment
+
+import java.lang.ref.WeakReference
+import java.util.ArrayList
+import java.util.HashMap
+
+class PageListAdapter
+// --------------------------- FragmentPagerAdapter ---------------------------
+
+(_activity: MainActivity) : FragmentPagerAdapter(_activity.fragmentManager) {
+
+    // ------------------------------ FIELDS ------------------------------
+
+    private val pages = ArrayList<PageInfo>()
+    private val fragmentCache = HashMap<Int, WeakReference<PageFragment<*>>>()
+
+    @Synchronized override fun getItem(position: Int): PageFragment<*> {
+        val pf: PageFragment<*>
+        val info = pages[position]
+        try {
+            pf = info.fragmentClass.newInstance()
+        } catch (e: Exception) {
+            Logger.error("should not happen: fragmentClass is private or Android is broken?")
+            e.printStackTrace()
+            throw RuntimeException(e)
+        }
+
+        pf.arguments = info.args
+        fragmentCache.put(position, WeakReference(pf))
+        return pf
+    }
+
+    @Synchronized
+    fun getCachedFragment(pos: Int): PageFragment<*>? {
+        val wpf = fragmentCache[pos]
+        return wpf?.get()
+    }
+
+    @Synchronized override fun getCount(): Int {
+        return pages.size
+    }
+
+    // ------------------------ INTERFACE METHODS ------------------------
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    fun addPage(klass: Class<out PageFragment<*>>, name: String, args: Bundle) {
+        this.addPage(klass, name, args, true)
+    }
+
+    fun addPage(klass: Class<out PageFragment<*>>, name: String, args: Bundle, notifyChanged: Boolean) {
+        pages.add(PageInfo(klass, name, args))
+        if (notifyChanged) notifyDataSetChanged()
+    }
+
+    @Synchronized
+    fun removePage(position: Int): Boolean {
+        //if (removePageWithoutNotify(position)) {
+        //    refreshListNavigation();
+        //    return true;
+        //}
+        return pages.removeAt(position) != null // TODO
+    }
+
+    fun getName(pos: Int): String {
+        return pages[pos].name
+    }
+
+    @Deprecated("")
+    fun getIndex(fragmentClass: Class<out PageFragment<*>>): Int {
+        for (i in pages.indices) {
+            if (pages[i].fragmentClass == fragmentClass) {
+                return i
+            }
+        }
+        return -1
+    }
+
+    private class PageInfo internal constructor(val fragmentClass: Class<out PageFragment<*>>, val name: String, val args: Bundle)
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.java b/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.java
deleted file mode 100644
index 0dbe8d53..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.java
+++ /dev/null
@@ -1,39 +0,0 @@
-package net.lacolaco.smileessence.view.adapter;
-
-import android.app.Activity;
-import android.view.View;
-import android.view.ViewGroup;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.view.Partials;
-
-import java.util.*;
-
-public class TimelineAdapter extends OrderedCustomListAdapter<Tweet> {
-    private final Activity activity;
-
-    public TimelineAdapter(Activity activity) {
-        super();
-        this.activity = activity;
-    }
-
-    public long getLastID() {
-        if (getCount() > 0) {
-            return getItem(getCount() - 1).getId();
-        } else {
-            return -1;
-        }
-    }
-
-    public long getTopID() {
-        if (getCount() > 0) {
-            return getItem(0).getId();
-        } else {
-            return -1;
-        }
-    }
-
-    @Override
-    public View getView(int position, View convertView, ViewGroup parent) {
-        return Partials.getTweetView(getItem(position), activity, convertView, true);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.kt
new file mode 100644
index 00000000..750b63a0
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/adapter/TimelineAdapter.kt
@@ -0,0 +1,29 @@
+package net.lacolaco.smileessence.view.adapter
+
+import android.app.Activity
+import android.view.View
+import android.view.ViewGroup
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.view.Partials
+
+import java.util.*
+
+class TimelineAdapter(private val activity: Activity) : OrderedCustomListAdapter<Tweet>() {
+    val lastID: Long
+        get() = if (count > 0) {
+            getItem(count - 1).id
+        } else {
+            -1
+        }
+
+    val topID: Long
+        get() = if (count > 0) {
+            getItem(0).id
+        } else {
+            -1
+        }
+
+    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+        return Partials.getTweetView(getItem(position), activity, convertView, true)
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.java
deleted file mode 100644
index 74dcc468..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.java
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.Activity;
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.content.DialogInterface;
-import android.os.Bundle;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.view.DialogHelper;
-
-public abstract class ConfirmDialogFragment extends StackableDialogFragment {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private static final String ARG_TEXT = "text";
-    private final DialogInterface.OnClickListener listener = (dialog, which) -> {
-        onButtonClick(which);
-        dialog.dismiss();
-    };
-    private String text;
-
-    // -------------------------- STATIC METHODS --------------------------
-
-    public static void show(Activity activity, String text, final Runnable onYes) {
-        show(activity, text, onYes, null, true);
-    }
-
-    public static void show(Activity activity, String text, final Runnable onYes, boolean ignorable) {
-        show(activity, text, onYes, null, ignorable);
-    }
-
-    public static void show(Activity activity, String text, final Runnable onOK, final Runnable onCancel, boolean ignorable) {
-        boolean confirm = UserPreferenceHelper.getInstance().get(R.string.key_setting_show_confirm_dialog, true);
-        if (!confirm && ignorable) {
-            onOK.run();
-            return;
-        }
-        final ConfirmDialogFragment fragment = new ConfirmDialogFragment() {
-            @Override
-            public void onButtonClick(int which) {
-                switch (which) {
-                    case DialogInterface.BUTTON_POSITIVE: {
-                        if (onOK != null) {
-                            dismiss();
-                            onOK.run();
-                        }
-                        break;
-                    }
-                    case DialogInterface.BUTTON_NEGATIVE: {
-                        if (onCancel != null) {
-                            dismiss();
-                            onCancel.run();
-                        }
-                        break;
-                    }
-                }
-            }
-        };
-        fragment.setText(text);
-        DialogHelper.showDialog(activity, fragment);
-    }
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    public void setText(String text) {
-        Bundle args = new Bundle();
-        args.putString(ARG_TEXT, text);
-        setArguments(args);
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        Bundle args = getArguments();
-        if (args != null) {
-            text = args.getString(ARG_TEXT);
-        }
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        return new AlertDialog.Builder(getActivity()).setTitle(text)
-                .setCancelable(false)
-                .setPositiveButton(R.string.alert_dialog_ok, listener)
-                .setNegativeButton(R.string.alert_dialog_cancel, listener)
-                .create();
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    protected abstract void onButtonClick(int which);
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.kt
new file mode 100644
index 00000000..094aa18a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/ConfirmDialogFragment.kt
@@ -0,0 +1,119 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.Activity
+import android.app.AlertDialog
+import android.app.Dialog
+import android.content.DialogInterface
+import android.os.Bundle
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.view.DialogHelper
+
+abstract class ConfirmDialogFragment : StackableDialogFragment() {
+    private var text: String? = null
+
+    // --------------------- GETTER / SETTER METHODS ---------------------
+
+    fun setText(text: String) {
+        val args = Bundle()
+        args.putString(ARG_TEXT, text)
+        arguments = args
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        val args = arguments
+        if (args != null) {
+            text = args.getString(ARG_TEXT)
+        }
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        return AlertDialog.Builder(activity).setTitle(text)
+                .setCancelable(false)
+                .setPositiveButton(R.string.alert_dialog_ok, { dialog, which ->
+                    onButtonClick(which)
+                    dialog.dismiss()
+                })
+                .setNegativeButton(R.string.alert_dialog_cancel, { dialog, which ->
+                    onButtonClick(which)
+                    dialog.dismiss()
+                })
+                .create()
+    }
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    protected abstract fun onButtonClick(which: Int)
+
+    companion object {
+
+        // ------------------------------ FIELDS ------------------------------
+
+        private val ARG_TEXT = "text"
+
+        // -------------------------- STATIC METHODS --------------------------
+
+        fun show(activity: Activity, text: String, onYes: () -> Unit) {
+            show(activity, text, onYes, null, true)
+        }
+
+        fun show(activity: Activity, text: String, onYes: () -> Unit, ignorable: Boolean) {
+            show(activity, text, onYes, null, ignorable)
+        }
+
+        fun show(activity: Activity, text: String, onOK: (() -> Unit)?, onCancel: (() -> Unit)?, ignorable: Boolean) {
+            val confirm = UserPreferenceHelper.instance.get(R.string.key_setting_show_confirm_dialog, true)
+            if (!confirm && ignorable) {
+                onOK!!()
+                return
+            }
+            val fragment = object : ConfirmDialogFragment() {
+                public override fun onButtonClick(which: Int) {
+                    when (which) {
+                        DialogInterface.BUTTON_POSITIVE -> {
+                            if (onOK != null) {
+                                dismiss()
+                                onOK()
+                            }
+                        }
+                        DialogInterface.BUTTON_NEGATIVE -> {
+                            if (onCancel != null) {
+                                dismiss()
+                                onCancel()
+                            }
+                        }
+                    }
+                }
+            }
+            fragment.setText(text)
+            DialogHelper.showDialog(activity, fragment)
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/DisposeDialog.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/DisposeDialog.kt
index eb3d3613..3cd486bd 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/DisposeDialog.java
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/DisposeDialog.kt
@@ -22,22 +22,16 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.view.dialog;
+package net.lacolaco.smileessence.view.dialog
 
-import android.app.Dialog;
-import android.content.Context;
+import android.app.Dialog
+import android.content.Context
 
 /**
  * Dialog for dispose soon.
  */
-public final class DisposeDialog extends Dialog {
-
-    public DisposeDialog(Context context) {
-        super(context);
-    }
-
-    @Override
-    public void show() {
-        dismiss();
+class DisposeDialog(context: Context) : Dialog(context) {
+    override fun show() {
+        dismiss()
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.java
deleted file mode 100644
index 8ce25145..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.app.DialogFragment;
-import android.os.Bundle;
-import android.view.View;
-import android.widget.EditText;
-import net.lacolaco.smileessence.R;
-
-public abstract class EditTextDialogFragment extends DialogFragment {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private static final String titleKey = "title";
-    private static final String textKey = "text";
-    private String title;
-    private String text;
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        Bundle args = getArguments();
-        text = args.getString(textKey);
-        title = args.getString(titleKey);
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        View view = getActivity().getLayoutInflater().inflate(R.layout.part_edittext, null);
-        final EditText editText = (EditText) view.findViewById(R.id.part_edittext);
-        editText.setText(text);
-        return new AlertDialog.Builder(getActivity())
-                .setTitle(title)
-                .setView(view)
-                .setPositiveButton(R.string.alert_dialog_ok, (dialog, which) -> {
-                    onTextInput(editText.getText().toString());
-                    dialog.dismiss();
-                })
-                .setNegativeButton(R.string.alert_dialog_cancel, (dialog, which) -> dialog.dismiss())
-                .create();
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    public abstract void onTextInput(String text);
-
-    public void setParams(String title, String text) {
-        Bundle args = new Bundle();
-        args.putString(titleKey, title);
-        args.putString(textKey, text);
-        setArguments(args);
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.kt
new file mode 100644
index 00000000..399b84ad
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/EditTextDialogFragment.kt
@@ -0,0 +1,81 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.app.DialogFragment
+import android.os.Bundle
+import android.view.View
+import android.widget.EditText
+import net.lacolaco.smileessence.R
+
+abstract class EditTextDialogFragment : DialogFragment() {
+    private lateinit var title: String
+    private lateinit var text: String
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        val args = arguments
+        text = args.getString(textKey)
+        title = args.getString(titleKey)
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val view = activity.layoutInflater.inflate(R.layout.part_edittext, null)
+        val editText = view.findViewById(R.id.part_edittext) as EditText
+        editText.setText(text)
+        return AlertDialog.Builder(activity)
+                .setTitle(title)
+                .setView(view)
+                .setPositiveButton(R.string.alert_dialog_ok) { dialog, which ->
+                    onTextInput(editText.text.toString())
+                    dialog.dismiss()
+                }
+                .setNegativeButton(R.string.alert_dialog_cancel) { dialog, which -> dialog.dismiss() }
+                .create()
+    }
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    abstract fun onTextInput(text: String)
+
+    fun setParams(title: String, text: String) {
+        val args = Bundle()
+        args.putString(titleKey, title)
+        args.putString(textKey, text)
+        arguments = args
+    }
+
+    companion object {
+
+        // ------------------------------ FIELDS ------------------------------
+
+        private val titleKey = "title"
+        private val textKey = "text"
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.java
deleted file mode 100644
index f8a1e2e5..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.java
+++ /dev/null
@@ -1,250 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2015 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.graphics.drawable.ColorDrawable;
-import android.os.Bundle;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ImageButton;
-import android.widget.ListView;
-import android.widget.TextView;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.command.Command;
-import net.lacolaco.smileessence.command.CommandAddHashtag;
-import net.lacolaco.smileessence.command.CommandOpenURL;
-import net.lacolaco.smileessence.command.CommandOpenUserDetail;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.twitter.task.Messages;
-import net.lacolaco.smileessence.util.SystemServiceHelper;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.Partials;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-import net.lacolaco.smileessence.view.adapter.MessageListAdapter;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class MessageDetailDialogFragment extends StackableDialogFragment implements View.OnClickListener {
-    private static final String KEY_MESSAGE_ID = "message_id";
-    private DirectMessage message;
-
-    public static MessageDetailDialogFragment newInstance(DirectMessage message) {
-        MessageDetailDialogFragment obj = new MessageDetailDialogFragment();
-        Bundle args = new Bundle();
-        args.putLong(KEY_MESSAGE_ID, message.getId());
-        obj.setArguments(args);
-        return obj;
-    }
-
-    @Override
-    public void onClick(final View v) {
-        switch (v.getId()) {
-            case R.id.button_status_detail_reply: {
-                openSendMessageDialog();
-                break;
-            }
-            case R.id.button_status_detail_delete: {
-                deleteMessage();
-                break;
-            }
-            case R.id.button_status_detail_menu: {
-                openMenu();
-                break;
-            }
-            default: {
-                dismiss();
-            }
-        }
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        message = DirectMessage.fetch(getArguments().getLong(KEY_MESSAGE_ID));
-        if (message == null) {
-            getWorld().notifyError(R.string.notice_error_get_messages);
-            return new DisposeDialog(getActivity());
-        }
-
-        View header = getTitleView();
-        ListView listView = (ListView) header.findViewById(R.id.listview_status_detail_reply_to);
-        final MessageListAdapter adapter = new MessageListAdapter(getActivity());
-        listView.setAdapter(adapter);
-
-        // TODO: 効率的な探索どうする
-        DirectMessage replyTo = null;
-        // FIXME
-        // for (DirectMessage mes : DirectMessage.cached()) {
-        //     if (message.getId() > mes.getId() &&
-        //             message.getRecipient() == mes.getSender() &&
-        //             message.getSender() == mes.getRecipient() &&
-        //             (replyTo == null || replyTo.getId() < mes.getId())) {
-        //         replyTo = mes;
-        //     }
-        // }
-        if (replyTo != null) {
-            listView.setVisibility(View.VISIBLE);
-            adapter.add(replyTo);
-            adapter.updateForce();
-        } else {
-            listView.setVisibility(View.GONE);
-        }
-
-        return new AlertDialog.Builder(getActivity()).setView(header).create();
-    }
-
-    // -------------------------- OTHER METHODS --------------------------
-
-    private void deleteMessage() {
-        ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), () -> {
-            new Messages.DestroyTask(getWorld().getAccount(), message.getId())
-                    .onDone(x -> getWorld().notify(R.string.notice_message_delete_succeeded))
-                    .onFail(x -> getWorld().notifyError(R.string.notice_message_delete_failed))
-                    .execute();
-            dismiss();
-        });
-    }
-
-    private void openSendMessageDialog() {
-        DialogHelper.showDialog(getActivity(), SendMessageDialogFragment.newInstance(message.getSender()));
-    }
-
-    private View getTitleView() {
-        MainActivity activity = (MainActivity) getActivity();
-
-        View view = activity.getLayoutInflater().inflate(R.layout.dialog_status_detail, null);
-
-        View messageHeader = Partials.getDirectMessageView(message, activity, view.findViewById(R.id.layout_status_header));
-        messageHeader.setClickable(false);
-
-        view.setBackgroundColor(((ColorDrawable) messageHeader.getBackground()).getColor());
-        updateViewButtons(view);
-        updateViewMenu(view);
-
-        // status only parts
-        view.findViewById(R.id.detail_dialog_divider_top).setVisibility(View.GONE);
-        view.findViewById(R.id.button_status_detail_retweet).setVisibility(View.GONE);
-        view.findViewById(R.id.button_status_detail_favorite).setVisibility(View.GONE);
-        view.findViewById(R.id.image_status_detail_fav_count).setVisibility(View.GONE);
-        view.findViewById(R.id.image_status_detail_rt_count).setVisibility(View.GONE);
-
-        return view;
-    }
-
-    private void updateViewButtons(View view) {
-        //--- buttons
-        ImageButton reply = (ImageButton) view.findViewById(R.id.button_status_detail_reply);
-        reply.setOnClickListener(this);
-
-        ImageButton delete = (ImageButton) view.findViewById(R.id.button_status_detail_delete);
-        delete.setOnClickListener(this);
-        delete.setVisibility(View.VISIBLE);
-    }
-
-    private void updateViewMenu(View view) {
-        // -- menu dialog
-        ImageButton menu = (ImageButton) view.findViewById(R.id.button_status_detail_menu);
-        menu.setOnClickListener(this);
-
-        // -- menu embedded in dialog
-        View divider = view.findViewById(R.id.detail_dialog_divider_bottom);
-        ListView listView = (ListView) view.findViewById(R.id.listview_status_detail_menu);
-        List<Command> commands = getCommands();
-        if (commands.size() > 0) {
-            divider.setVisibility(View.VISIBLE);
-            listView.setVisibility(View.VISIBLE);
-            final CustomListAdapter<Command> adapter = new CustomListAdapter<Command>() {
-                @Override
-                public View getView(int position, View convertView, ViewGroup parent) {
-                    if (convertView == null) {
-                        convertView = getActivity().getLayoutInflater().inflate(R.layout.menu_item_simple_text, null);
-                    }
-                    TextView textView = (TextView) convertView.findViewById(R.id.list_item_textview);
-                    textView.setTextSize(UserPreferenceHelper.getInstance().getTextSize());
-                    textView.setText(getItem(position).getText());
-                    return convertView;
-                }
-
-                @Override
-                protected List<Command> getList() {
-                    return commands;
-                }
-            };
-            adapter.update();
-            listView.setAdapter(adapter);
-            listView.setOnItemClickListener((parent, view1, position, id) -> {
-                Command command = (Command) parent.getItemAtPosition(position);
-                command.execute();
-            });
-        } else {
-            divider.setVisibility(View.GONE);
-            listView.setVisibility(View.GONE);
-        }
-    }
-
-    private List<Command> getCommands() {
-        MainActivity activity = (MainActivity) getActivity();
-        List<Command> commands = new ArrayList<>();
-        // Mentions
-        if (message.getSender() != message.getRecipient()) {
-            commands.add(new CommandOpenUserDetail(activity, message.getRecipient().getScreenName()));
-        }
-        for (String screenName : message.getMentions()) {
-            commands.add(new CommandOpenUserDetail(activity, screenName));
-        }
-        for (String hashtag : message.getHashtags()) {
-            commands.add(new CommandAddHashtag(activity, hashtag));
-        }
-        // URL
-        for (String url : message.getUrlsExpanded()) {
-            commands.add(new CommandOpenURL(activity, url));
-        }
-        for (String url : message.getMediaUrls()) {
-            commands.add(new CommandOpenURL(activity, url));
-        }
-        return commands;
-    }
-
-    private void openMenu() {
-        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
-        builder.setTitle("@" + message.getSender().getScreenName() + ": " + message.getText())
-                .setItems(R.array.message_commands, (dialog, which) -> {
-                    switch (which) {
-                        case 0:
-                            SystemServiceHelper.copyToClipboard(getActivity(), "message text", message.getText());
-                            getWorld().notify(R.string.notice_copy_clipboard);
-                            break;
-                        default:
-                            throw new IllegalStateException();
-                    }
-                });
-        AlertDialog dialog = builder.create();
-        dialog.show();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.kt
new file mode 100644
index 00000000..36f7584f
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/MessageDetailDialogFragment.kt
@@ -0,0 +1,246 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2015 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.graphics.drawable.ColorDrawable
+import android.os.Bundle
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageButton
+import android.widget.ListView
+import android.widget.TextView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.command.Command
+import net.lacolaco.smileessence.command.CommandAddHashtag
+import net.lacolaco.smileessence.command.CommandOpenURL
+import net.lacolaco.smileessence.command.CommandOpenUserDetail
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.twitter.task.Messages
+import net.lacolaco.smileessence.util.SystemServiceHelper
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.Partials
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+import net.lacolaco.smileessence.view.adapter.MessageListAdapter
+
+import java.util.ArrayList
+
+class MessageDetailDialogFragment : StackableDialogFragment(), View.OnClickListener {
+    private lateinit var message: DirectMessage
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.button_status_detail_reply -> {
+                openSendMessageDialog()
+            }
+            R.id.button_status_detail_delete -> {
+                deleteMessage()
+            }
+            R.id.button_status_detail_menu -> {
+                openMenu()
+            }
+            else -> {
+                dismiss()
+            }
+        }
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val found = DirectMessage.fetch(arguments.getLong(KEY_MESSAGE_ID))
+        if (found == null) {
+            world.notifyError(R.string.notice_error_get_messages)
+            return DisposeDialog(activity)
+        }
+        message = found
+
+        val header = titleView
+        val listView = header.findViewById(R.id.listview_status_detail_reply_to) as ListView
+        val adapter = MessageListAdapter(activity)
+        listView.adapter = adapter
+
+        // TODO: 効率的な探索どうする
+        val replyTo: DirectMessage? = null
+        // FIXME
+        // for (DirectMessage mes : DirectMessage.cached()) {
+        //     if (message.getId() > mes.getId() &&
+        //             message.getRecipient() == mes.getSender() &&
+        //             message.getSender() == mes.getRecipient() &&
+        //             (replyTo == null || replyTo.getId() < mes.getId())) {
+        //         replyTo = mes;
+        //     }
+        // }
+        if (replyTo != null) {
+            listView.visibility = View.VISIBLE
+            adapter.add(replyTo)
+            adapter.updateForce()
+        } else {
+            listView.visibility = View.GONE
+        }
+
+        return AlertDialog.Builder(activity).setView(header).create()
+    }
+
+    // -------------------------- OTHER METHODS --------------------------
+
+    private fun deleteMessage() {
+        ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands)) {
+            Messages.DestroyTask(world.account, message.id)
+                    .onDone { x -> world.notify(R.string.notice_message_delete_succeeded) }
+                    .onFail { x -> world.notifyError(R.string.notice_message_delete_failed) }
+                    .execute()
+            dismiss()
+        }
+    }
+
+    private fun openSendMessageDialog() {
+        DialogHelper.showDialog(activity, SendMessageDialogFragment.newInstance(message.sender))
+    }
+
+    private // status only parts
+    val titleView: View
+        get() {
+            val activity = activity as MainActivity
+
+            val view = activity.layoutInflater.inflate(R.layout.dialog_status_detail, null)
+
+            val messageHeader = Partials.getDirectMessageView(message, activity, view.findViewById(R.id.layout_status_header))
+            messageHeader.isClickable = false
+
+            view.setBackgroundColor((messageHeader.background as ColorDrawable).color)
+            updateViewButtons(view)
+            updateViewMenu(view)
+            view.findViewById(R.id.detail_dialog_divider_top).visibility = View.GONE
+            view.findViewById(R.id.button_status_detail_retweet).visibility = View.GONE
+            view.findViewById(R.id.button_status_detail_favorite).visibility = View.GONE
+            view.findViewById(R.id.image_status_detail_fav_count).visibility = View.GONE
+            view.findViewById(R.id.image_status_detail_rt_count).visibility = View.GONE
+
+            return view
+        }
+
+    private fun updateViewButtons(view: View) {
+        //--- buttons
+        val reply = view.findViewById(R.id.button_status_detail_reply) as ImageButton
+        reply.setOnClickListener(this)
+
+        val delete = view.findViewById(R.id.button_status_detail_delete) as ImageButton
+        delete.setOnClickListener(this)
+        delete.visibility = View.VISIBLE
+    }
+
+    private fun updateViewMenu(view: View) {
+        // -- menu dialog
+        val menu = view.findViewById(R.id.button_status_detail_menu) as ImageButton
+        menu.setOnClickListener(this)
+
+        // -- menu embedded in dialog
+        val divider = view.findViewById(R.id.detail_dialog_divider_bottom)
+        val listView = view.findViewById(R.id.listview_status_detail_menu) as ListView
+        val commands = commands
+        if (commands.size > 0) {
+            divider.visibility = View.VISIBLE
+            listView.visibility = View.VISIBLE
+            val adapter = object : CustomListAdapter<Command>() {
+                override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+                    var convertView = convertView
+                    if (convertView == null) {
+                        convertView = activity.layoutInflater.inflate(R.layout.menu_item_simple_text, null)
+                    }
+                    val textView = convertView!!.findViewById(R.id.list_item_textview) as TextView
+                    textView.textSize = UserPreferenceHelper.instance.textSize.toFloat()
+                    textView.text = getItem(position).text
+                    return convertView
+                }
+
+                override val list: List<Command>
+                    get() = commands
+            }
+            adapter.update()
+            listView.adapter = adapter
+            listView.setOnItemClickListener { parent, view1, position, id ->
+                val command = parent.getItemAtPosition(position) as Command
+                command.execute()
+            }
+        } else {
+            divider.visibility = View.GONE
+            listView.visibility = View.GONE
+        }
+    }
+
+    private // Mentions
+            // URL
+    val commands: List<Command>
+        get() {
+            val activity = activity as MainActivity
+            val commands = ArrayList<Command>()
+            if (message.sender !== message.recipient) {
+                commands.add(CommandOpenUserDetail(activity, message.recipient.screenName))
+            }
+            for (screenName in message.mentions) {
+                commands.add(CommandOpenUserDetail(activity, screenName))
+            }
+            for (hashtag in message.hashtags) {
+                commands.add(CommandAddHashtag(activity, hashtag))
+            }
+            for (url in message.urlsExpanded) {
+                commands.add(CommandOpenURL(activity, url))
+            }
+            for (url in message.mediaUrls) {
+                commands.add(CommandOpenURL(activity, url))
+            }
+            return commands
+        }
+
+    private fun openMenu() {
+        val builder = AlertDialog.Builder(activity)
+        builder.setTitle("@" + message.sender.screenName + ": " + message.text)
+                .setItems(R.array.message_commands) { dialog, which ->
+                    when (which) {
+                        0 -> {
+                            SystemServiceHelper.copyToClipboard(activity, "message text", message.text)
+                            world.notify(R.string.notice_copy_clipboard)
+                        }
+                        else -> throw IllegalStateException()
+                    }
+                }
+        val dialog = builder.create()
+        dialog.show()
+    }
+
+    companion object {
+        private val KEY_MESSAGE_ID = "message_id"
+
+        fun newInstance(message: DirectMessage): MessageDetailDialogFragment {
+            val obj = MessageDetailDialogFragment()
+            val args = Bundle()
+            args.putLong(KEY_MESSAGE_ID, message.id)
+            obj.arguments = args
+            return obj
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.java
deleted file mode 100644
index 20917d8f..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.java
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.os.Bundle;
-import android.support.v4.content.ContextCompat;
-import android.text.Editable;
-import android.text.TextUtils;
-import android.text.TextWatcher;
-import android.view.View;
-import android.widget.Button;
-import android.widget.EditText;
-import android.widget.ImageButton;
-import android.widget.TextView;
-import com.twitter.Validator;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.twitter.task.Messages;
-import net.lacolaco.smileessence.util.SystemServiceHelper;
-
-public class SendMessageDialogFragment extends StackableDialogFragment implements TextWatcher, View.OnClickListener {
-    private static final String KEY_RECIPIENT_ID = "KEY_RECIPIENT_ID";
-    private User recipient;
-    private EditText editText;
-    private TextView textViewCount;
-    private Button buttonSend;
-
-    public static SendMessageDialogFragment newInstance(User recipient) {
-        SendMessageDialogFragment obj = new SendMessageDialogFragment();
-        Bundle args = new Bundle();
-        args.putLong(KEY_RECIPIENT_ID, recipient.getId());
-        obj.setArguments(args);
-        return obj;
-    }
-    @Override
-    public void onClick(View v) {
-        int id = v.getId();
-        switch (id) {
-            case R.id.button_send_message: {
-                sendMessage();
-                break;
-            }
-            case R.id.button_send_message_delete: {
-                deleteMessage();
-            }
-        }
-    }
-
-    @Override
-    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
-
-    }
-
-    @Override
-    public void onTextChanged(CharSequence s, int start, int before, int count) {
-        Validator validator = new Validator();
-        int remainingCount = 140 - validator.getTweetLength(s.toString());
-        textViewCount.setText(String.valueOf(remainingCount));
-        if (remainingCount == 140 || remainingCount < 0) {
-            textViewCount.setTextColor(ContextCompat.getColor(getActivity(), R.color.red));
-        } else {
-            textViewCount.setTextAppearance(getActivity(), android.R.style.TextAppearance_Widget_TextView);
-        }
-    }
-
-    @Override
-    public void afterTextChanged(Editable s) {
-
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        recipient = User.fetch(getArguments().getLong(KEY_RECIPIENT_ID));
-        View view = getActivity().getLayoutInflater().inflate(R.layout.dialog_send_message, null);
-        TextView textViewName = (TextView) view.findViewById(R.id.textview_send_message_name);
-        textViewName.setText("To: @" + recipient.getScreenName());
-        textViewCount = (TextView) view.findViewById(R.id.textview_send_message_count);
-        editText = (EditText) view.findViewById(R.id.edittext_send_message);
-        editText.addTextChangedListener(this);
-        buttonSend = (Button) view.findViewById(R.id.button_send_message);
-        buttonSend.setOnClickListener(this);
-        ImageButton buttonDelete = (ImageButton) view.findViewById(R.id.button_send_message_delete);
-        buttonDelete.setOnClickListener(this);
-        editText.setText("");
-        return new AlertDialog.Builder(getActivity())
-                .setView(view)
-                .create();
-    }
-
-    private void deleteMessage() {
-        editText.setText("");
-    }
-
-    private void sendMessage() {
-        SystemServiceHelper.hideIM(getActivity(), editText);
-        String text = editText.getText().toString();
-        new Messages.CreateTask(getWorld().getAccount(), recipient.getId(), text)
-                .onDoneUI(m -> {
-                    getWorld().addDirectMessage(m);
-                    getWorld().notify(R.string.notice_message_send_succeeded);
-                    dismiss();
-                })
-                .onFail(e -> getWorld().notifyError(R.string.notice_message_send_failed, e))
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.kt
new file mode 100644
index 00000000..fb7e9d2f
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/SendMessageDialogFragment.kt
@@ -0,0 +1,127 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.os.Bundle
+import android.support.v4.content.ContextCompat
+import android.text.Editable
+import android.text.TextUtils
+import android.text.TextWatcher
+import android.view.View
+import android.widget.Button
+import android.widget.EditText
+import android.widget.ImageButton
+import android.widget.TextView
+import com.twitter.Validator
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.entity.User
+import net.lacolaco.smileessence.twitter.task.Messages
+import net.lacolaco.smileessence.util.SystemServiceHelper
+
+class SendMessageDialogFragment : StackableDialogFragment(), TextWatcher, View.OnClickListener {
+    private var recipient: User? = null
+    private var editText: EditText? = null
+    private var textViewCount: TextView? = null
+    private var buttonSend: Button? = null
+    override fun onClick(v: View) {
+        val id = v.id
+        when (id) {
+            R.id.button_send_message -> {
+                sendMessage()
+            }
+            R.id.button_send_message_delete -> {
+                deleteMessage()
+            }
+        }
+    }
+
+    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {
+
+    }
+
+    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
+        val validator = Validator()
+        val remainingCount = 140 - validator.getTweetLength(s.toString())
+        textViewCount!!.text = remainingCount.toString()
+        if (remainingCount == 140 || remainingCount < 0) {
+            textViewCount!!.setTextColor(ContextCompat.getColor(activity, R.color.red))
+        } else {
+            textViewCount!!.setTextAppearance(activity, android.R.style.TextAppearance_Widget_TextView)
+        }
+    }
+
+    override fun afterTextChanged(s: Editable) {
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        recipient = User.fetch(arguments.getLong(KEY_RECIPIENT_ID))
+        val view = activity.layoutInflater.inflate(R.layout.dialog_send_message, null)
+        val textViewName = view.findViewById(R.id.textview_send_message_name) as TextView
+        textViewName.text = "To: @" + recipient!!.screenName
+        textViewCount = view.findViewById(R.id.textview_send_message_count) as TextView
+        editText = view.findViewById(R.id.edittext_send_message) as EditText
+        editText!!.addTextChangedListener(this)
+        buttonSend = view.findViewById(R.id.button_send_message) as Button
+        buttonSend!!.setOnClickListener(this)
+        val buttonDelete = view.findViewById(R.id.button_send_message_delete) as ImageButton
+        buttonDelete.setOnClickListener(this)
+        editText!!.setText("")
+        return AlertDialog.Builder(activity)
+                .setView(view)
+                .create()
+    }
+
+    private fun deleteMessage() {
+        editText!!.setText("")
+    }
+
+    private fun sendMessage() {
+        SystemServiceHelper.hideIM(activity, editText)
+        val text = editText!!.text.toString()
+        Messages.CreateTask(world.account, recipient!!.id, text)
+                .onDoneUI { m ->
+                    world.addDirectMessage(m)
+                    world.notify(R.string.notice_message_send_succeeded)
+                    dismiss()
+                }
+                .onFail { e -> world.notifyError(R.string.notice_message_send_failed, e) }
+                .execute()
+    }
+
+    companion object {
+        private val KEY_RECIPIENT_ID = "KEY_RECIPIENT_ID"
+
+        fun newInstance(recipient: User): SendMessageDialogFragment {
+            val obj = SendMessageDialogFragment()
+            val args = Bundle()
+            args.putLong(KEY_RECIPIENT_ID, recipient.id)
+            obj.arguments = args
+            return obj
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.java
deleted file mode 100644
index 848c6465..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.DialogFragment;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.view.DialogHelper;
-
-/**
- * Only used by MainActivity.
- */
-public class StackableDialogFragment extends DialogFragment {
-    @Override
-    public void dismiss() {
-        super.dismiss();
-        DialogHelper.unregisterDialog(getTag());
-    }
-
-    @Override
-    public void dismissAllowingStateLoss() {
-        super.dismissAllowingStateLoss();
-        DialogHelper.unregisterDialog(getTag());
-    }
-
-    protected World getWorld() {
-        final MainActivity activity = (MainActivity) getActivity();
-        return activity.getWorld();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.kt
new file mode 100644
index 00000000..7822cfe3
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StackableDialogFragment.kt
@@ -0,0 +1,25 @@
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.DialogFragment
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.view.DialogHelper
+
+/**
+ * Only used by MainActivity.
+ */
+open class StackableDialogFragment : DialogFragment() {
+    override fun dismiss() {
+        super.dismiss()
+        DialogHelper.unregisterDialog(tag)
+    }
+
+    override fun dismissAllowingStateLoss() {
+        super.dismissAllowingStateLoss()
+        DialogHelper.unregisterDialog(tag)
+    }
+
+    protected val world: World by lazy {
+        (activity as MainActivity).world
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.java
deleted file mode 100644
index 5b2ee58c..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.java
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.graphics.drawable.ColorDrawable;
-import android.os.Bundle;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ImageButton;
-import android.widget.ImageView;
-import android.widget.ListView;
-import android.widget.TextView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.command.Command;
-import net.lacolaco.smileessence.command.CommandAddHashtag;
-import net.lacolaco.smileessence.command.CommandOpenURL;
-import net.lacolaco.smileessence.command.CommandOpenUserDetail;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.RBinding;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.twitter.task.TweetReactions;
-import net.lacolaco.smileessence.twitter.task.Tweets;
-import net.lacolaco.smileessence.util.IntentUtils;
-import net.lacolaco.smileessence.util.SystemServiceHelper;
-import net.lacolaco.smileessence.util.UIObserverBundle;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.Partials;
-import net.lacolaco.smileessence.view.ToggleableImageButton;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-import java.util.LinkedHashSet;
-import java.util.List;
-
-public class StatusDetailDialogFragment extends StackableDialogFragment implements View.OnClickListener {
-    private static final String KEY_STATUS_ID = "status_id";
-    private Tweet tweet;
-
-    public static StatusDetailDialogFragment newInstance(Tweet tweet) {
-        StatusDetailDialogFragment obj = new StatusDetailDialogFragment();
-        Bundle args = new Bundle();
-        args.putLong(KEY_STATUS_ID, tweet.getId());
-        obj.setArguments(args);
-        return obj;
-    }
-
-    @Override
-    public void onClick(final View v) {
-        switch (v.getId()) {
-            case R.id.button_status_detail_reply: {
-                Tweet originalTweet = tweet.getOriginalTweet();
-
-                StringBuilder builder = new StringBuilder();
-                builder.append("@" + originalTweet.getUser().getScreenName() + " ");
-
-                for (String screenName : originalTweet.getMentions()) {
-                    if (!screenName.equals(getWorld().getAccount().getUser().getScreenName()))
-                        builder.append("@" + screenName + " ");
-                }
-                String text = builder.toString();
-                int selStart = originalTweet.getUser().getScreenName().length() + 2; // "@" and " "
-
-                getWorld().getPostState().beginTransaction()
-                        .clear()
-                        .insertText(0, text)
-                        .setInReplyTo(originalTweet)
-                        .setSelection(selStart, text.length())
-                        .commitWithOpen((MainActivity) getActivity());
-                break;
-            }
-            case R.id.button_status_detail_retweet: {
-                Account account = getWorld().getAccount();
-                confirm(() -> {
-                    if (tweet.isRetweetedBy(account.getUserId())) {
-                        new Tweets.DestroyTask(account, tweet.getRetweetIdBy(account.getUserId()))
-                                .onDone(t -> getWorld().notify(R.string.notice_status_delete_succeeded))
-                                .onFail(e -> getWorld().notifyError(R.string.notice_status_delete_failed))
-                                .execute();
-                        dismiss();
-                    } else {
-                        new TweetReactions.RetweetTask(account, tweet.getId())
-                                .onDone(x -> getWorld().notify(R.string.notice_retweet_succeeded))
-                                .onFail(x -> getWorld().notifyError(R.string.notice_retweet_failed))
-                                .execute();
-                    }
-                });
-                break;
-            }
-            case R.id.button_status_detail_favorite: {
-                Account account = getWorld().getAccount();
-                if (tweet.isFavoritedBy(account.getUserId())) {
-                    new TweetReactions.UnfavoriteTask(account, tweet.getId())
-                            .onDone(x -> getWorld().notify(R.string.notice_unfavorite_succeeded))
-                            .onFail(x -> getWorld().notifyError(R.string.notice_unfavorite_failed))
-                            .execute();
-                } else {
-                    new TweetReactions.FavoriteTask(account, tweet.getId())
-                            .onDone(x -> getWorld().notify(R.string.notice_favorite_succeeded))
-                            .onFail(x -> getWorld().notifyError(R.string.notice_favorite_failed))
-                            .execute();
-                }
-                break;
-            }
-            case R.id.button_status_detail_delete: {
-                confirm(() -> {
-                    new Tweets.DestroyTask(getWorld().getAccount(), tweet.getOriginalTweet().getId())
-                            .onDone(t -> getWorld().notify(R.string.notice_status_delete_succeeded))
-                            .onFail(e -> getWorld().notifyError(R.string.notice_status_delete_failed))
-                            .execute();
-                    dismiss();
-                });
-                break;
-            }
-            case R.id.button_status_detail_menu: {
-                AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
-                builder.setTitle("@" + tweet.getUser().getScreenName() + ": " + tweet.getText())
-                        .setItems(R.array.status_commands, (dialog, which) -> {
-                            switch (which) {
-                                case 0:
-                                    String text = String.format("@%s ", tweet.getOriginalTweet().getUser().getScreenName());
-                                    getWorld().getPostState().beginTransaction().insertText(0, text).moveCursor(text.length()).commit();
-                                    getWorld().notify(R.string.notice_add_to_reply);
-                                    break;
-                                case 1:
-                                    TalkChainDialogFragment dialogFragment = new TalkChainDialogFragment();
-                                    dialogFragment.setStatusID(tweet.getOriginalTweet().getId());
-                                    DialogHelper.showDialog(getActivity(), dialogFragment);
-                                    break;
-                                case 2:
-                                    IntentUtils.openUri(getActivity(), tweet.getOriginalTweet().getTwitterUrl());
-                                    break;
-                                case 3:
-                                    SystemServiceHelper.copyToClipboard(getActivity(), "tweet text", tweet.getOriginalTweet().getText());
-                                    getWorld().notify(R.string.notice_copy_clipboard);
-                                    break;
-                                case 4:
-                                    String statusURL = tweet.getOriginalTweet().getTwitterUrl();
-                                    SystemServiceHelper.copyToClipboard(getActivity(), "tweet url", statusURL);
-                                    getWorld().notify(R.string.notice_copy_clipboard);
-                                    break;
-                                default:
-                                    throw new IllegalStateException();
-                            }
-                        });
-                AlertDialog dialog = builder.create();
-                dialog.show();
-                break;
-            }
-            default: {
-                dismiss();
-            }
-        }
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        tweet = Tweet.fetch(getArguments().getLong(KEY_STATUS_ID));
-        if (tweet == null) { // trying to open deleted tweet?
-            getWorld().notifyError(R.string.notice_error_show_status);
-            return new DisposeDialog(getActivity());
-        }
-
-        View view = getActivity().getLayoutInflater().inflate(R.layout.dialog_status_detail, null);
-        UIObserverBundle bundle = new UIObserverBundle();
-        view.setTag(bundle);
-
-        View statusHeader = Partials.getTweetView(tweet, getActivity(), view.findViewById(R.id.layout_status_header), true);
-        statusHeader.setClickable(false);
-
-        view.setBackgroundColor(((ColorDrawable) statusHeader.getBackground()).getColor());
-        updateViewReactions(view);
-        updateViewButtons(view);
-        setupViewMenu(view);
-
-        final WeakReference<View> weakView = new WeakReference<>(view);
-        bundle.attach(tweet.getOriginalTweet(), changes -> {
-            View strongView = weakView.get();
-            if (strongView != null && getActivity() != null) {
-                if (changes.contains(RBinding.REACTION_COUNT))
-                    updateViewReactions(strongView);
-                if (changes.contains(RBinding.FAVORITERS) || changes.contains(RBinding.RETWEETERS))
-                    updateViewButtons(strongView);
-            }
-        });
-
-        ListView listView = (ListView) view.findViewById(R.id.listview_status_detail_reply_to);
-        final TimelineAdapter adapter = new TimelineAdapter(getActivity());
-        listView.setAdapter(adapter);
-
-        View replyDivider = view.findViewById(R.id.detail_dialog_divider_top);
-
-        if (tweet.getInReplyToStatusId() != -1) {
-            replyDivider.setVisibility(View.VISIBLE);
-            listView.setVisibility(View.VISIBLE);
-            Tweet.fetchTask(tweet.getInReplyToStatusId(), getWorld().getAccount())
-                    .onDoneUI(replyTo -> {
-                        adapter.add(replyTo);
-                        adapter.update();
-                    })
-                    .execute();
-        } else {
-            replyDivider.setVisibility(View.GONE);
-            listView.setVisibility(View.GONE);
-        }
-
-        return new AlertDialog.Builder(getActivity()).setView(view).create();
-    }
-
-    private void updateViewReactions(View view) {
-        ImageView favCountIcon = (ImageView) view.findViewById(R.id.image_status_detail_fav_count);
-        TextView favCountText = (TextView) view.findViewById(R.id.textview_status_detail_fav_count);
-        if (tweet.getFavoriteCount() > 0) {
-            favCountText.setText(Integer.toString(tweet.getFavoriteCount()));
-            favCountIcon.setVisibility(View.VISIBLE);
-            favCountText.setVisibility(View.VISIBLE);
-        } else {
-            favCountIcon.setVisibility(View.GONE);
-            favCountText.setVisibility(View.GONE);
-        }
-
-        ImageView rtCountIcon = (ImageView) view.findViewById(R.id.image_status_detail_rt_count);
-        TextView rtCountText = (TextView) view.findViewById(R.id.textview_status_detail_rt_count);
-        if (tweet.getRetweetCount() > 0) {
-            rtCountText.setText(Integer.toString(tweet.getRetweetCount()));
-            rtCountIcon.setVisibility(View.VISIBLE);
-            rtCountText.setVisibility(View.VISIBLE);
-        } else {
-            rtCountIcon.setVisibility(View.GONE);
-            rtCountText.setVisibility(View.GONE);
-        }
-    }
-
-    private void updateViewButtons(View view) {
-        Account account = getWorld().getAccount();
-
-        //--- buttons
-        ImageButton reply = (ImageButton) view.findViewById(R.id.button_status_detail_reply);
-        reply.setOnClickListener(this);
-
-        ToggleableImageButton retweet = (ToggleableImageButton) view.findViewById(R.id.button_status_detail_retweet);
-        retweet.setOnClickListener(this);
-        retweet.setState(tweet.isRetweetedBy(account.getUserId()));
-
-        ToggleableImageButton favorite = (ToggleableImageButton) view.findViewById(R.id.button_status_detail_favorite);
-        favorite.setOnClickListener(this);
-        favorite.setState(tweet.isFavoritedBy(account.getUserId()));
-
-        ImageButton delete = (ImageButton) view.findViewById(R.id.button_status_detail_delete);
-        delete.setOnClickListener(this);
-        delete.setVisibility(tweet.getOriginalTweet().getUser() == account.getUser() ? View.VISIBLE : View.GONE);
-
-        ImageButton menu = (ImageButton) view.findViewById(R.id.button_status_detail_menu);
-        menu.setOnClickListener(this);
-    }
-
-    private void setupViewMenu(View view) {
-        View divider = view.findViewById(R.id.detail_dialog_divider_bottom);
-        ListView listView = (ListView) view.findViewById(R.id.listview_status_detail_menu);
-        List<Command> commands = getCommands();
-        if (commands.size() > 0) {
-            divider.setVisibility(View.VISIBLE);
-            listView.setVisibility(View.VISIBLE);
-            final CustomListAdapter<Command> adapter = new CustomListAdapter<Command>() {
-                @Override
-                public View getView(int position, View convertView, ViewGroup parent) {
-                    if (convertView == null) {
-                        convertView = getActivity().getLayoutInflater().inflate(R.layout.menu_item_simple_text, null);
-                    }
-                    TextView textView = (TextView) convertView.findViewById(R.id.list_item_textview);
-                    textView.setTextSize(UserPreferenceHelper.getInstance().getTextSize());
-                    textView.setText(getItem(position).getText());
-                    return convertView;
-                }
-
-                @Override
-                protected List<Command> getList() {
-                    return commands;
-                }
-            };
-            adapter.update();
-            listView.setAdapter(adapter);
-            listView.setOnItemClickListener((parent, view1, position, id) -> {
-                Command command = (Command) parent.getItemAtPosition(position);
-                command.execute();
-            });
-        } else {
-            divider.setVisibility(View.GONE);
-            listView.setVisibility(View.GONE);
-        }
-    }
-
-    private void confirm(Runnable onYes) {
-        ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), onYes);
-    }
-
-    private List<Command> getCommands() {
-        MainActivity activity = (MainActivity) getActivity();
-        ArrayList<Command> commands = new ArrayList<>();
-        // Retweeter
-        if (tweet.getRetweetedTweet() != null && tweet.getUser() != tweet.getRetweetedTweet().getUser())
-            commands.add(new CommandOpenUserDetail(activity, tweet.getUser().getScreenName()));
-        // Mentions
-        for (String screenName : new ArrayList<>(new LinkedHashSet<>(tweet.getMentions()))) { // Array#uniq
-            commands.add(new CommandOpenUserDetail(activity, screenName));
-        }
-        // Hashtags
-        for (String hashtag : tweet.getHashtags()) {
-            commands.add(new CommandAddHashtag(activity, hashtag));
-        }
-        // URL
-        for (String url : tweet.getUrlsExpanded()) {
-            commands.add(new CommandOpenURL(activity, url));
-        }
-        for (String url : tweet.getMediaUrls()) {
-            commands.add(new CommandOpenURL(activity, url));
-        }
-        return commands;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.kt
new file mode 100644
index 00000000..c18b6b4d
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.kt
@@ -0,0 +1,339 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.graphics.drawable.ColorDrawable
+import android.os.Bundle
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageButton
+import android.widget.ImageView
+import android.widget.ListView
+import android.widget.TextView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.command.Command
+import net.lacolaco.smileessence.command.CommandAddHashtag
+import net.lacolaco.smileessence.command.CommandOpenURL
+import net.lacolaco.smileessence.command.CommandOpenUserDetail
+import net.lacolaco.smileessence.data.Account
+import net.lacolaco.smileessence.entity.RBinding
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.twitter.task.TweetReactions
+import net.lacolaco.smileessence.twitter.task.Tweets
+import net.lacolaco.smileessence.util.IntentUtils
+import net.lacolaco.smileessence.util.SystemServiceHelper
+import net.lacolaco.smileessence.util.UIObserverBundle
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.Partials
+import net.lacolaco.smileessence.view.ToggleableImageButton
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+
+import java.lang.ref.WeakReference
+import java.util.ArrayList
+import java.util.LinkedHashSet
+
+class StatusDetailDialogFragment : StackableDialogFragment(), View.OnClickListener {
+    private lateinit var tweet: Tweet
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.button_status_detail_reply -> {
+                val originalTweet = tweet.originalTweet
+
+                val builder = StringBuilder()
+                builder.append("@" + originalTweet.user.screenName + " ")
+
+                for (screenName in originalTweet.mentions) {
+                    if (screenName != world.account.user.screenName)
+                        builder.append("@$screenName ")
+                }
+                val text = builder.toString()
+                val selStart = originalTweet.user.screenName.length + 2 // "@" and " "
+
+                world.postState.beginTransaction()
+                        .clear()
+                        .insertText(0, text)
+                        .setInReplyTo(originalTweet)
+                        .setSelection(selStart, text.length)
+                        .commitWithOpen(activity as MainActivity)
+            }
+            R.id.button_status_detail_retweet -> {
+                val account = world.account
+                confirm({
+                    if (tweet.isRetweetedBy(account.userId)) {
+                        Tweets.DestroyTask(account, tweet.getRetweetIdBy(account.userId))
+                                .onDone { t -> world.notify(R.string.notice_status_delete_succeeded) }
+                                .onFail { e -> world.notifyError(R.string.notice_status_delete_failed) }
+                                .execute()
+                        dismiss()
+                    } else {
+                        TweetReactions.RetweetTask(account, tweet.id)
+                                .onDone { x -> world.notify(R.string.notice_retweet_succeeded) }
+                                .onFail { x -> world.notifyError(R.string.notice_retweet_failed) }
+                                .execute()
+                    }
+                })
+            }
+            R.id.button_status_detail_favorite -> {
+                val account = world.account
+                if (tweet.isFavoritedBy(account.userId)) {
+                    TweetReactions.UnfavoriteTask(account, tweet.id)
+                            .onDone { x -> world.notify(R.string.notice_unfavorite_succeeded) }
+                            .onFail { x -> world.notifyError(R.string.notice_unfavorite_failed) }
+                            .execute()
+                } else {
+                    TweetReactions.FavoriteTask(account, tweet.id)
+                            .onDone { x -> world.notify(R.string.notice_favorite_succeeded) }
+                            .onFail { x -> world.notifyError(R.string.notice_favorite_failed) }
+                            .execute()
+                }
+            }
+            R.id.button_status_detail_delete -> {
+                confirm({
+                    Tweets.DestroyTask(world.account, tweet.originalTweet.id)
+                            .onDone { t -> world.notify(R.string.notice_status_delete_succeeded) }
+                            .onFail { e -> world.notifyError(R.string.notice_status_delete_failed) }
+                            .execute()
+                    dismiss()
+                })
+            }
+            R.id.button_status_detail_menu -> {
+                val builder = AlertDialog.Builder(activity)
+                builder.setTitle("@" + tweet.user.screenName + ": " + tweet.text)
+                        .setItems(R.array.status_commands) { dialog, which ->
+                            when (which) {
+                                0 -> {
+                                    val text = String.format("@%s ", tweet.originalTweet.user.screenName)
+                                    world.postState.beginTransaction().insertText(0, text).moveCursor(text.length).commit()
+                                    world.notify(R.string.notice_add_to_reply)
+                                }
+                                1 -> {
+                                    DialogHelper.showDialog(activity, TalkChainDialogFragment.newInstance(tweet))
+                                }
+                                2 -> IntentUtils.openUri(activity, tweet.originalTweet.twitterUrl)
+                                3 -> {
+                                    SystemServiceHelper.copyToClipboard(activity, "tweet text", tweet.originalTweet.text)
+                                    world.notify(R.string.notice_copy_clipboard)
+                                }
+                                4 -> {
+                                    val statusURL = tweet.originalTweet.twitterUrl
+                                    SystemServiceHelper.copyToClipboard(activity, "tweet url", statusURL)
+                                    world.notify(R.string.notice_copy_clipboard)
+                                }
+                                else -> throw IllegalStateException()
+                            }
+                        }
+                val dialog = builder.create()
+                dialog.show()
+            }
+            else -> {
+                dismiss()
+            }
+        }
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val found = Tweet.fetch(arguments.getLong(KEY_STATUS_ID))
+        if (found == null) { // trying to open deleted tweet?
+            world.notifyError(R.string.notice_error_show_status)
+            return DisposeDialog(activity)
+        }
+        tweet = found
+
+        val view = activity.layoutInflater.inflate(R.layout.dialog_status_detail, null)
+        val bundle = UIObserverBundle()
+        view.tag = bundle
+
+        val statusHeader = Partials.getTweetView(tweet, activity, view.findViewById(R.id.layout_status_header), true)
+        statusHeader.isClickable = false
+
+        view.setBackgroundColor((statusHeader.background as ColorDrawable).color)
+        updateViewReactions(view)
+        updateViewButtons(view)
+        setupViewMenu(view)
+
+        val weakView = WeakReference(view)
+        bundle.attach(tweet.originalTweet) { changes ->
+            val strongView = weakView.get()
+            if (strongView != null && activity != null) {
+                if (changes.contains(RBinding.REACTION_COUNT))
+                    updateViewReactions(strongView)
+                if (changes.contains(RBinding.FAVORITERS) || changes.contains(RBinding.RETWEETERS))
+                    updateViewButtons(strongView)
+            }
+        }
+
+        val listView = view.findViewById(R.id.listview_status_detail_reply_to) as ListView
+        val adapter = TimelineAdapter(activity)
+        listView.adapter = adapter
+
+        val replyDivider = view.findViewById(R.id.detail_dialog_divider_top)
+
+        if (tweet.inReplyToStatusId != -1L) {
+            replyDivider.visibility = View.VISIBLE
+            listView.visibility = View.VISIBLE
+            Tweet.fetchTask(tweet.inReplyToStatusId, world.account)
+                    .onDoneUI { replyTo ->
+                        adapter.add(replyTo)
+                        adapter.update()
+                    }
+                    .execute()
+        } else {
+            replyDivider.visibility = View.GONE
+            listView.visibility = View.GONE
+        }
+
+        return AlertDialog.Builder(activity).setView(view).create()
+    }
+
+    private fun updateViewReactions(view: View) {
+        val favCountIcon = view.findViewById(R.id.image_status_detail_fav_count) as ImageView
+        val favCountText = view.findViewById(R.id.textview_status_detail_fav_count) as TextView
+        if (tweet.favoriteCount > 0) {
+            favCountText.text = Integer.toString(tweet.favoriteCount)
+            favCountIcon.visibility = View.VISIBLE
+            favCountText.visibility = View.VISIBLE
+        } else {
+            favCountIcon.visibility = View.GONE
+            favCountText.visibility = View.GONE
+        }
+
+        val rtCountIcon = view.findViewById(R.id.image_status_detail_rt_count) as ImageView
+        val rtCountText = view.findViewById(R.id.textview_status_detail_rt_count) as TextView
+        if (tweet.retweetCount > 0) {
+            rtCountText.text = Integer.toString(tweet.retweetCount)
+            rtCountIcon.visibility = View.VISIBLE
+            rtCountText.visibility = View.VISIBLE
+        } else {
+            rtCountIcon.visibility = View.GONE
+            rtCountText.visibility = View.GONE
+        }
+    }
+
+    private fun updateViewButtons(view: View) {
+        val account = world.account
+
+        //--- buttons
+        val reply = view.findViewById(R.id.button_status_detail_reply) as ImageButton
+        reply.setOnClickListener(this)
+
+        val retweet = view.findViewById(R.id.button_status_detail_retweet) as ToggleableImageButton
+        retweet.setOnClickListener(this)
+        retweet.setState(tweet.isRetweetedBy(account.userId))
+
+        val favorite = view.findViewById(R.id.button_status_detail_favorite) as ToggleableImageButton
+        favorite.setOnClickListener(this)
+        favorite.setState(tweet.isFavoritedBy(account.userId))
+
+        val delete = view.findViewById(R.id.button_status_detail_delete) as ImageButton
+        delete.setOnClickListener(this)
+        delete.visibility = if (tweet.originalTweet.user === account.user) View.VISIBLE else View.GONE
+
+        val menu = view.findViewById(R.id.button_status_detail_menu) as ImageButton
+        menu.setOnClickListener(this)
+    }
+
+    private fun setupViewMenu(view: View) {
+        val divider = view.findViewById(R.id.detail_dialog_divider_bottom)
+        val listView = view.findViewById(R.id.listview_status_detail_menu) as ListView
+        val commands = commands
+        if (commands.size > 0) {
+            divider.visibility = View.VISIBLE
+            listView.visibility = View.VISIBLE
+            val adapter = object : CustomListAdapter<Command>() {
+                override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+                    var convertView = convertView
+                    if (convertView == null) {
+                        convertView = activity.layoutInflater.inflate(R.layout.menu_item_simple_text, null)
+                    }
+                    val textView = convertView!!.findViewById(R.id.list_item_textview) as TextView
+                    textView.textSize = UserPreferenceHelper.instance.textSize.toFloat()
+                    textView.text = getItem(position).text
+                    return convertView
+                }
+
+                override val list: List<Command>
+                    get() = commands
+            }
+            adapter.update()
+            listView.adapter = adapter
+            listView.setOnItemClickListener { parent, view1, position, id ->
+                val command = parent.getItemAtPosition(position) as Command
+                command.execute()
+            }
+        } else {
+            divider.visibility = View.GONE
+            listView.visibility = View.GONE
+        }
+    }
+
+    private fun confirm(onYes: () -> Unit) {
+        ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands), onYes)
+    }
+
+    private // Retweeter
+            // Mentions
+            // Array#uniq
+            // Hashtags
+            // URL
+    val commands: List<Command>
+        get() {
+            val activity = activity as MainActivity
+            val commands = ArrayList<Command>()
+            if (tweet.retweetedTweet != null && tweet.user !== tweet.retweetedTweet!!.user)
+                commands.add(CommandOpenUserDetail(activity, tweet.user.screenName))
+            for (screenName in ArrayList(LinkedHashSet(tweet.mentions))) {
+                commands.add(CommandOpenUserDetail(activity, screenName))
+            }
+            for (hashtag in tweet.hashtags) {
+                commands.add(CommandAddHashtag(activity, hashtag))
+            }
+            for (url in tweet.urlsExpanded) {
+                commands.add(CommandOpenURL(activity, url))
+            }
+            for (url in tweet.mediaUrls) {
+                commands.add(CommandOpenURL(activity, url))
+            }
+            return commands
+        }
+
+    companion object {
+        private val KEY_STATUS_ID = "status_id"
+
+        fun newInstance(tweet: Tweet): StatusDetailDialogFragment {
+            val obj = StatusDetailDialogFragment()
+            val args = Bundle()
+            args.putLong(KEY_STATUS_ID, tweet.id)
+            obj.arguments = args
+            return obj
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.java
deleted file mode 100644
index 95bbac5c..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.java
+++ /dev/null
@@ -1,89 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.os.Bundle;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ListView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.twitter.task.Tweets;
-import net.lacolaco.smileessence.view.Partials;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class TalkChainDialogFragment extends StackableDialogFragment {
-    private static final String KEY_STATUS_ID = "KEY_STATUS_ID";
-
-    private long getStatusID() {
-        return getArguments().getLong(KEY_STATUS_ID);
-    }
-
-    public void setStatusID(long id) {
-        Bundle bundle = new Bundle();
-        bundle.putLong(KEY_STATUS_ID, id);
-        setArguments(bundle);
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        Account account = getWorld().getAccount();
-
-        View view = getActivity().getLayoutInflater().inflate(R.layout.dialog_talk_list, null);
-        ListView listView = (ListView) view.findViewById(R.id.listview_dialog_talk_list);
-        final List<Tweet> list = new ArrayList<>();
-        final CustomListAdapter<Tweet> adapter = new CustomListAdapter<Tweet>() {
-            @Override
-            public View getView(int position, View convertView, ViewGroup parent) {
-                return Partials.getTweetView(getItem(position), getActivity(), convertView, true);
-            }
-
-            @Override
-            protected List<Tweet> getList() {
-                return list;
-            }
-        };
-        listView.setAdapter(adapter);
-
-        new Tweets.GetTalkTask(account, getStatusID()).onProgressUI(tweet -> {
-            list.add(tweet);
-            adapter.updateForce();
-        }).execute();
-
-        return new AlertDialog.Builder(getActivity())
-                .setTitle(R.string.dialog_title_talk_chain)
-                .setView(view)
-                .setCancelable(true)
-                .create();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.kt
new file mode 100644
index 00000000..1b39e50a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/TalkChainDialogFragment.kt
@@ -0,0 +1,81 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.os.Bundle
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ListView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.twitter.task.Tweets
+import net.lacolaco.smileessence.view.Partials
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+
+import java.util.ArrayList
+
+class TalkChainDialogFragment : StackableDialogFragment() {
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val account = world.account
+
+        val view = activity.layoutInflater.inflate(R.layout.dialog_talk_list, null)
+        val listView = view.findViewById(R.id.listview_dialog_talk_list) as ListView
+        val list = ArrayList<Tweet>()
+        val adapter = object : CustomListAdapter<Tweet>() {
+            override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+                return Partials.getTweetView(getItem(position), activity, convertView, true)
+            }
+
+            override val list: List<Tweet>
+                get() = list
+        }
+        listView.adapter = adapter
+
+        Tweets.GetTalkTask(account, arguments.getLong(KEY_STATUS_ID)).onProgressUI { tweet ->
+            list.add(tweet)
+            adapter.updateForce()
+        }.execute()
+
+        return AlertDialog.Builder(activity)
+                .setTitle(R.string.dialog_title_talk_chain)
+                .setView(view)
+                .setCancelable(true)
+                .create()
+    }
+
+    companion object {
+        private val KEY_STATUS_ID = "KEY_STATUS_ID"
+
+        fun newInstance(tweet: Tweet): TalkChainDialogFragment {
+            val obj = TalkChainDialogFragment()
+            val bundle = Bundle()
+            bundle.putLong(KEY_STATUS_ID, tweet.originalTweet.id)
+            obj.arguments = bundle
+            return obj
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.java
deleted file mode 100644
index c8d62fa8..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.java
+++ /dev/null
@@ -1,423 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.dialog;
-
-import android.app.AlertDialog;
-import android.app.Dialog;
-import android.os.Bundle;
-import android.text.Html;
-import android.text.TextUtils;
-import android.text.method.LinkMovementMethod;
-import android.view.View;
-import android.widget.AbsListView;
-import android.widget.ListView;
-import android.widget.TabHost;
-import android.widget.TextView;
-import com.android.volley.toolbox.NetworkImageView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import com.handmark.pulltorefresh.library.PullToRefreshListView;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.data.Account;
-import net.lacolaco.smileessence.data.ImageCache;
-import net.lacolaco.smileessence.entity.RBinding;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.twitter.task.Timelines;
-import net.lacolaco.smileessence.twitter.task.Users;
-import net.lacolaco.smileessence.util.IntentUtils;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.util.UIObserverBundle;
-import net.lacolaco.smileessence.view.DialogHelper;
-import net.lacolaco.smileessence.view.ThreeStateButton;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-
-public class UserDetailDialogFragment extends StackableDialogFragment implements View.OnClickListener,
-        PullToRefreshBase.OnRefreshListener2<ListView> {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private static final String KEY_USER_ID = "userID";
-    private TimelineAdapter adapter;
-    private TextView textViewScreenName;
-    private TextView textViewName;
-    private TextView textViewURL;
-    private TextView textViewLocate;
-    private TextView textViewFollowed;
-    private TextView textViewProtected;
-    private TextView textViewDescription;
-    private TextView textViewTweetCount;
-    private TextView textViewFriendCount;
-    private TextView textViewFollowerCount;
-    private TextView textViewFavoriteCount;
-    private NetworkImageView imageViewIcon;
-    private NetworkImageView imageViewHeader;
-    private ThreeStateButton buttonFollow;
-    private PullToRefreshListView listViewTimeline;
-    private TabHost tabHost;
-    private UIObserverBundle observerBundle;
-    private User user;
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    public long getUserID() {
-        return getArguments().getLong(KEY_USER_ID);
-    }
-
-    public void setUserID(long userID) {
-        Bundle args = new Bundle();
-        args.putLong(KEY_USER_ID, userID);
-        setArguments(args);
-    }
-
-    // ------------------------ INTERFACE METHODS ------------------------
-
-
-    // --------------------- Interface OnClickListener ---------------------
-
-    @Override
-    public void onClick(final View v) {
-        switch (v.getId()) {
-            case R.id.imageview_user_detail_menu: {
-                openUserMenu();
-                break;
-            }
-            case R.id.imageview_user_detail_icon: {
-                IntentUtils.openUri(getActivity(), user.getProfileImageUrlOriginal());
-                break;
-            }
-            case R.id.textview_user_detail_screenname:
-            case R.id.textview_user_detail_tweet_count: {
-                IntentUtils.openUri(getActivity(), user.getUserHomeURL());
-                break;
-            }
-            case R.id.textview_user_detail_friend_count: {
-                IntentUtils.openUri(getActivity(), String.format("%s/following", user.getUserHomeURL()));
-                break;
-            }
-            case R.id.textview_user_detail_follower_count: {
-                IntentUtils.openUri(getActivity(), String.format("%s/followers", user.getUserHomeURL()));
-                break;
-            }
-            case R.id.textview_user_detail_favorite_count: {
-                IntentUtils.openUri(getActivity(), String.format("%s/favorites", user.getUserHomeURL()));
-                break;
-            }
-            case R.id.button_user_detail_follow: {
-                ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), this::toggleFollowing);
-                break;
-            }
-        }
-    }
-
-    // --------------------- Interface OnRefreshListener2 ---------------------
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        Account currentAccount = getWorld().getAccount();
-        new Timelines.UserTimelineTask(currentAccount, getUserID())
-                .setCount(200)
-                .setSinceId(adapter.getTopID())
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_user_timeline))
-                .onDoneUI(tweets -> {
-                    adapter.addAll(tweets);
-                    updateListView(refreshView.getRefreshableView(), adapter, true);
-                    refreshView.onRefreshComplete();
-                })
-                .execute();
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        Account currentAccount = getWorld().getAccount();
-        new Timelines.UserTimelineTask(currentAccount, getUserID())
-                .setCount(200)
-                .setMaxId(adapter.getLastID() - 1)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_user_timeline))
-                .onDoneUI(tweets -> {
-                    adapter.addAll(tweets);
-                    updateListView(refreshView.getRefreshableView(), adapter, false);
-                    refreshView.onRefreshComplete();
-                })
-                .execute();
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        user = User.fetch(getUserID());
-        observerBundle = new UIObserverBundle();
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        observerBundle.detachAll();
-    }
-
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        MainActivity activity = (MainActivity) getActivity();
-        if (user == null) {
-            getWorld().notify(R.string.notice_error_show_user);
-            return new DisposeDialog(activity);
-        }
-
-        View v = activity.getLayoutInflater().inflate(R.layout.dialog_user_detail, null);
-        View menu = v.findViewById(R.id.imageview_user_detail_menu);
-        menu.setOnClickListener(this);
-        textViewScreenName = (TextView) v.findViewById(R.id.textview_user_detail_screenname);
-        textViewScreenName.setOnClickListener(this);
-        textViewName = (TextView) v.findViewById(R.id.textview_user_detail_name);
-        textViewURL = (TextView) v.findViewById(R.id.textview_user_detail_url);
-        textViewLocate = (TextView) v.findViewById(R.id.textview_user_detail_locate);
-        textViewFollowed = (TextView) v.findViewById(R.id.textview_user_detail_followed);
-        textViewProtected = (TextView) v.findViewById(R.id.texttview_user_detail_protected);
-        textViewDescription = (TextView) v.findViewById(R.id.textview_user_detail_description);
-        textViewDescription.setMovementMethod(LinkMovementMethod.getInstance());
-        textViewTweetCount = (TextView) v.findViewById(R.id.textview_user_detail_tweet_count);
-        textViewTweetCount.setOnClickListener(this);
-        textViewFriendCount = (TextView) v.findViewById(R.id.textview_user_detail_friend_count);
-        textViewFriendCount.setOnClickListener(this);
-        textViewFollowerCount = (TextView) v.findViewById(R.id.textview_user_detail_follower_count);
-        textViewFollowerCount.setOnClickListener(this);
-        textViewFavoriteCount = (TextView) v.findViewById(R.id.textview_user_detail_favorite_count);
-        textViewFavoriteCount.setOnClickListener(this);
-        imageViewIcon = (NetworkImageView) v.findViewById(R.id.imageview_user_detail_icon);
-        imageViewIcon.setOnClickListener(this);
-        imageViewHeader = (NetworkImageView) v.findViewById(R.id.imageview_user_detail_header);
-        buttonFollow = (ThreeStateButton) v.findViewById(R.id.button_user_detail_follow);
-        buttonFollow.setOnClickListener(this);
-        listViewTimeline = (PullToRefreshListView) v.findViewById(R.id.listview_user_detail_timeline);
-        listViewTimeline.setOnRefreshListener(this);
-
-        tabHost = (TabHost) v.findViewById(android.R.id.tabhost);
-        tabHost.setup();
-        TabHost.TabSpec tab1 = tabHost.newTabSpec("tab1").setContent(R.id.tab1).setIndicator(getString(R.string.user_detail_tab_info));
-        tabHost.addTab(tab1);
-        TabHost.TabSpec tab2 = tabHost.newTabSpec("tab2").setContent(R.id.tab2).setIndicator(getString(R.string.user_detail_tab_timeline));
-        tabHost.addTab(tab2);
-        tabHost.setCurrentTab(0);
-
-        initUserData();
-
-        return new AlertDialog.Builder(activity)
-                .setView(v)
-                .setCancelable(true)
-                .create();
-    }
-
-    private void executeUserTimelineTask(final TimelineAdapter adapter) {
-        Account account = getWorld().getAccount();
-        tabHost.getTabWidget().getChildTabViewAt(1).setVisibility(View.GONE);
-        new Timelines.UserTimelineTask(account, user.getId())
-                .setCount(200)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_user_timeline))
-                .onDoneUI(tweets -> {
-                    adapter.addAll(tweets);
-                    adapter.updateForce();
-                    tabHost.getTabWidget().getChildTabViewAt(1).setVisibility(View.VISIBLE);
-                })
-                .execute();
-    }
-
-    private String getHtmlDescription() {
-        String description = user.getDescription();
-        if (TextUtils.isEmpty(description)) {
-            return "";
-        }
-        String html = description;
-        html = html.replaceAll("https?://[\\w/:%#$&?()~.=+-]+", "<a href=\"$0\">$0</a>");
-        html = html.replaceAll("@([a-zA-Z0-9_]+)", "<a href=\"https://twitter.com/$1\">$0</a>");
-        html = html.replaceAll("\r\n", "<br />");
-        return html;
-    }
-
-    private void updateUserDataBasic() {
-        textViewName.setText(user.getName());
-        textViewScreenName.setText(user.getScreenName());
-        textViewProtected.setVisibility(user.isProtected() ? View.VISIBLE : View.GONE);
-        imageViewIcon.setImageUrl(user.getProfileImageUrlOriginal(), ImageCache.getImageLoader());
-    }
-
-    private void updateUserDataDetail() {
-        if (TextUtils.isEmpty(user.getLocation())) {
-            textViewLocate.setVisibility(View.GONE);
-        } else {
-            textViewLocate.setText(user.getLocation());
-            textViewLocate.setVisibility(View.VISIBLE);
-        }
-        if (TextUtils.isEmpty(user.getUrl())) {
-            textViewURL.setVisibility(View.GONE);
-        } else {
-            textViewURL.setText(user.getUrl());
-            textViewURL.setVisibility(View.VISIBLE);
-        }
-        textViewDescription.setText(Html.fromHtml(getHtmlDescription()));
-
-        textViewTweetCount.setText(String.valueOf(user.getStatusesCount()));
-        textViewFriendCount.setText(String.valueOf(user.getFriendsCount()));
-        textViewFollowerCount.setText(String.valueOf(user.getFollowersCount()));
-        textViewFavoriteCount.setText(String.valueOf(user.getFavoritesCount()));
-
-        imageViewHeader.setImageUrl(user.getProfileBannerUrl(), ImageCache.getImageLoader());
-    }
-
-    private void initUserData() {
-        updateUserDataBasic();
-        updateUserDataDetail();
-
-        MainActivity activity = (MainActivity) getActivity();
-        adapter = new TimelineAdapter(activity);
-        listViewTimeline.setAdapter(adapter);
-        executeUserTimelineTask(adapter);
-        updateRelationship();
-
-        observerBundle.attach(user, changes -> {
-            if (getActivity() != null) {
-                if (changes.contains(RBinding.BASIC))
-                    updateUserDataBasic();
-                if (changes.contains(RBinding.DETAIL))
-                    updateUserDataDetail();
-            }
-        });
-    }
-
-    private void openUserMenu() {
-        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
-        builder.setTitle("@" + user.getScreenName())
-                .setItems(R.array.user_commands, (dialog, which) -> {
-                    // XXX
-                    new UIHandler().postDelayed(() -> {
-                        if (UserDetailDialogFragment.this.isAdded()) {
-                            updateRelationship();
-                        }
-                    }, 1000);
-                    switch (which) {
-                        case 0:
-                            String text = String.format("@%s ", user.getScreenName());
-                            getWorld().getPostState().beginTransaction().insertText(0, text).moveCursor(text.length()).commit();
-                            getWorld().notify(R.string.notice_add_to_reply);
-                            break;
-                        case 1:
-                            DialogHelper.showDialog(getActivity(), SendMessageDialogFragment.newInstance(user));
-                            break;
-                        case 2:
-                            ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), () ->
-                                    new Users.BlockTask(getWorld().getAccount(), user.getId())
-                                            .onDone(user -> getWorld().notify(R.string.notice_block_succeeded))
-                                            .onFail(ex -> getWorld().notifyError(R.string.notice_block_failed))
-                                            .execute());
-                            break;
-                        case 3:
-                            ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), () ->
-                                    new Users.UnblockTask(getWorld().getAccount(), user.getId())
-                                            .onDone(user -> getWorld().notify(R.string.notice_unblock_succeeded))
-                                            .onFail(x -> getWorld().notifyError(R.string.notice_unblock_failed))
-                                            .execute());
-                            break;
-                        case 4:
-                            ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_commands), () ->
-                                    new Users.ReportForSpamTask(getWorld().getAccount(), user.getId())
-                                            .onDone(user -> getWorld().notify(R.string.notice_r4s_succeeded))
-                                            .onFail(ex -> getWorld().notifyError(R.string.notice_r4s_failed))
-                                            .execute());
-                            break;
-                        case 5:
-                            IntentUtils.openUri(getActivity(), user.getAclogTimelineURL());
-                            break;
-                        default:
-                            throw new IllegalStateException();
-                    }
-                });
-        AlertDialog dialog = builder.create();
-        dialog.show();
-    }
-
-    private void setFollowButtonState(boolean isFollowing) {
-        MainActivity mainActivity = (MainActivity) getActivity();
-        if (mainActivity != null) {
-            buttonFollow.setState(isFollowing ? ThreeStateButton.STATE_ON : ThreeStateButton.STATE_OFF);
-        }
-    }
-
-    private void toggleFollowing() {
-        Account account = getWorld().getAccount();
-        Boolean isFollowing = buttonFollow.getState() == ThreeStateButton.STATE_ON;
-        buttonFollow.setState(ThreeStateButton.STATE_LOCKED);
-        if (isFollowing) {
-            new Users.UnfollowTask(account, user.getId())
-                    .onDoneUI(result -> {
-                        getWorld().notify(R.string.notice_unfollow_succeeded);
-                        updateRelationship();
-                    })
-                    .onFail(x ->
-                            getWorld().notifyError(R.string.notice_unfollow_failed))
-                    .execute();
-        } else {
-            new Users.FollowTask(account, user.getId())
-                    .onDoneUI(result -> {
-                        getWorld().notify(R.string.notice_follow_succeeded);
-                        updateRelationship();
-                    })
-                    .onFail(x -> getWorld().notifyError(R.string.notice_follow_failed))
-                    .execute();
-        }
-    }
-
-    private void updateListView(AbsListView absListView, TimelineAdapter adapter, boolean addedToTop) {
-        int before = adapter.getCount();
-        adapter.notifyDataSetChanged(); // synchronized call (not adapter#updateForce())
-        int after = adapter.getCount();
-        int increments = after - before;
-        if (increments > 0) {
-            if (addedToTop) {
-                absListView.setSelection(increments + 1);
-                absListView.smoothScrollToPositionFromTop(increments, 0);
-                absListView.setSelection(increments);
-            } else {
-                absListView.smoothScrollToPositionFromTop(before, 0);
-            }
-        }
-    }
-
-    private void updateRelationship() {
-        Account account = getWorld().getAccount();
-        if (user == account.getUser()) {
-            textViewFollowed.setText(R.string.user_detail_followed_is_me);
-            buttonFollow.setVisibility(View.GONE);
-        } else {
-            buttonFollow.setState(ThreeStateButton.STATE_LOCKED);
-            textViewFollowed.setText(R.string.user_detail_loading);
-            new Users.ShowFriendshipTask(account, user.getId()).onDoneUI(relationship -> {
-                boolean isFollowing = relationship.isSourceFollowingTarget();
-                boolean isFollowed = relationship.isSourceFollowedByTarget();
-                setFollowButtonState(isFollowing);
-                textViewFollowed.setText(isFollowed ? R.string.user_detail_followed : R.string.user_detail_not_followed);
-            }).execute();
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.kt
new file mode 100644
index 00000000..228a000a
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.kt
@@ -0,0 +1,390 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.dialog
+
+import android.app.AlertDialog
+import android.app.Dialog
+import android.os.Bundle
+import android.text.Html
+import android.text.TextUtils
+import android.text.method.LinkMovementMethod
+import android.view.View
+import android.widget.AbsListView
+import android.widget.ListView
+import android.widget.TabHost
+import android.widget.TextView
+import com.android.volley.toolbox.NetworkImageView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import com.handmark.pulltorefresh.library.PullToRefreshListView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.data.ImageCache
+import net.lacolaco.smileessence.entity.RBinding
+import net.lacolaco.smileessence.entity.User
+import net.lacolaco.smileessence.twitter.task.Timelines
+import net.lacolaco.smileessence.twitter.task.Users
+import net.lacolaco.smileessence.util.IntentUtils
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.util.UIObserverBundle
+import net.lacolaco.smileessence.view.DialogHelper
+import net.lacolaco.smileessence.view.ThreeStateButton
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+
+class UserDetailDialogFragment : StackableDialogFragment(), View.OnClickListener, PullToRefreshBase.OnRefreshListener2<ListView> {
+    private lateinit var adapter: TimelineAdapter
+    private lateinit var textViewScreenName: TextView
+    private lateinit var textViewName: TextView
+    private lateinit var textViewURL: TextView
+    private lateinit var textViewLocate: TextView
+    private lateinit var textViewFollowed: TextView
+    private lateinit var textViewProtected: TextView
+    private lateinit var textViewDescription: TextView
+    private lateinit var textViewTweetCount: TextView
+    private lateinit var textViewFriendCount: TextView
+    private lateinit var textViewFollowerCount: TextView
+    private lateinit var textViewFavoriteCount: TextView
+    private lateinit var imageViewIcon: NetworkImageView
+    private lateinit var imageViewHeader: NetworkImageView
+    private lateinit var buttonFollow: ThreeStateButton
+    private lateinit var listViewTimeline: PullToRefreshListView
+    private lateinit var tabHost: TabHost
+    private lateinit var observerBundle: UIObserverBundle
+    private lateinit var user: User
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.imageview_user_detail_menu -> {
+                openUserMenu()
+            }
+            R.id.imageview_user_detail_icon -> {
+                IntentUtils.openUri(activity, user.profileImageUrl!!)
+            }
+            R.id.textview_user_detail_screenname, R.id.textview_user_detail_tweet_count -> {
+                IntentUtils.openUri(activity, user.userHomeURL)
+            }
+            R.id.textview_user_detail_friend_count -> {
+                IntentUtils.openUri(activity, String.format("%s/following", user.userHomeURL))
+            }
+            R.id.textview_user_detail_follower_count -> {
+                IntentUtils.openUri(activity, String.format("%s/followers", user.userHomeURL))
+            }
+            R.id.textview_user_detail_favorite_count -> {
+                IntentUtils.openUri(activity, String.format("%s/favorites", user.userHomeURL))
+            }
+            R.id.button_user_detail_follow -> {
+                ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands)) { this.toggleFollowing() }
+            }
+        }
+    }
+
+    // --------------------- Interface OnRefreshListener2 ---------------------
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        val currentAccount = world.account
+        Timelines.UserTimelineTask(currentAccount, user.id)
+                .setCount(200)
+                .setSinceId(adapter.topID)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_user_timeline) }
+                .onDoneUI { tweets ->
+                    adapter.addAll(tweets)
+                    updateListView(refreshView.refreshableView, adapter, true)
+                    refreshView.onRefreshComplete()
+                }
+                .execute()
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        val currentAccount = world.account
+        Timelines.UserTimelineTask(currentAccount, user.id)
+                .setCount(200)
+                .setMaxId(adapter.lastID - 1)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_user_timeline) }
+                .onDoneUI { tweets ->
+                    adapter.addAll(tweets)
+                    updateListView(refreshView.refreshableView, adapter, false)
+                    refreshView.onRefreshComplete()
+                }
+                .execute()
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        observerBundle = UIObserverBundle()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        observerBundle.detachAll()
+    }
+
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val activity = activity as MainActivity
+        val found = User.fetch(arguments.getLong(KEY_USER_ID))
+        if (found == null) {
+            world.notify(R.string.notice_error_show_user)
+            return DisposeDialog(activity)
+        }
+        user = found
+
+        val v = activity.layoutInflater.inflate(R.layout.dialog_user_detail, null)
+        val menu = v.findViewById(R.id.imageview_user_detail_menu)
+        menu.setOnClickListener(this)
+        textViewScreenName = v.findViewById(R.id.textview_user_detail_screenname) as TextView
+        textViewScreenName.setOnClickListener(this)
+        textViewName = v.findViewById(R.id.textview_user_detail_name) as TextView
+        textViewURL = v.findViewById(R.id.textview_user_detail_url) as TextView
+        textViewLocate = v.findViewById(R.id.textview_user_detail_locate) as TextView
+        textViewFollowed = v.findViewById(R.id.textview_user_detail_followed) as TextView
+        textViewProtected = v.findViewById(R.id.texttview_user_detail_protected) as TextView
+        textViewDescription = v.findViewById(R.id.textview_user_detail_description) as TextView
+        textViewDescription.movementMethod = LinkMovementMethod.getInstance()
+        textViewTweetCount = v.findViewById(R.id.textview_user_detail_tweet_count) as TextView
+        textViewTweetCount.setOnClickListener(this)
+        textViewFriendCount = v.findViewById(R.id.textview_user_detail_friend_count) as TextView
+        textViewFriendCount.setOnClickListener(this)
+        textViewFollowerCount = v.findViewById(R.id.textview_user_detail_follower_count) as TextView
+        textViewFollowerCount.setOnClickListener(this)
+        textViewFavoriteCount = v.findViewById(R.id.textview_user_detail_favorite_count) as TextView
+        textViewFavoriteCount.setOnClickListener(this)
+        imageViewIcon = v.findViewById(R.id.imageview_user_detail_icon) as NetworkImageView
+        imageViewIcon.setOnClickListener(this)
+        imageViewHeader = v.findViewById(R.id.imageview_user_detail_header) as NetworkImageView
+        buttonFollow = v.findViewById(R.id.button_user_detail_follow) as ThreeStateButton
+        buttonFollow.setOnClickListener(this)
+        listViewTimeline = v.findViewById(R.id.listview_user_detail_timeline) as PullToRefreshListView
+        listViewTimeline.setOnRefreshListener(this)
+
+        tabHost = v.findViewById(android.R.id.tabhost) as TabHost
+        tabHost.setup()
+        val tab1 = tabHost.newTabSpec("tab1").setContent(R.id.tab1).setIndicator(getString(R.string.user_detail_tab_info))
+        tabHost.addTab(tab1)
+        val tab2 = tabHost.newTabSpec("tab2").setContent(R.id.tab2).setIndicator(getString(R.string.user_detail_tab_timeline))
+        tabHost.addTab(tab2)
+        tabHost.currentTab = 0
+
+        initUserData()
+
+        return AlertDialog.Builder(activity)
+                .setView(v)
+                .setCancelable(true)
+                .create()
+    }
+
+    private fun executeUserTimelineTask(adapter: TimelineAdapter) {
+        val account = world.account
+        tabHost.tabWidget.getChildTabViewAt(1).visibility = View.GONE
+        Timelines.UserTimelineTask(account, user.id)
+                .setCount(200)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_user_timeline) }
+                .onDoneUI { tweets ->
+                    adapter.addAll(tweets)
+                    adapter.updateForce()
+                    tabHost.tabWidget.getChildTabViewAt(1).visibility = View.VISIBLE
+                }
+                .execute()
+    }
+
+    private val htmlDescription: String?
+        get() {
+            val description = user.description
+            if (TextUtils.isEmpty(description)) {
+                return ""
+            }
+            var html = description
+            html = html!!.replace("https?://[\\w/:%#$&?()~.=+-]+".toRegex(), "<a href=\"$0\">$0</a>")
+            html = html.replace("@([a-zA-Z0-9_]+)".toRegex(), "<a href=\"https://twitter.com/$1\">$0</a>")
+            html = html.replace("\r\n".toRegex(), "<br />")
+            return html
+        }
+
+    private fun updateUserDataBasic() {
+        textViewName.text = user.name
+        textViewScreenName.text = user.screenName
+        textViewProtected.visibility = if (user.isProtected) View.VISIBLE else View.GONE
+        imageViewIcon.setImageUrl(user.profileImageUrl, ImageCache.getImageLoader())
+    }
+
+    private fun updateUserDataDetail() {
+        if (TextUtils.isEmpty(user.location)) {
+            textViewLocate.visibility = View.GONE
+        } else {
+            textViewLocate.text = user.location
+            textViewLocate.visibility = View.VISIBLE
+        }
+        if (TextUtils.isEmpty(user.url)) {
+            textViewURL.visibility = View.GONE
+        } else {
+            textViewURL.text = user.url
+            textViewURL.visibility = View.VISIBLE
+        }
+        textViewDescription.text = Html.fromHtml(htmlDescription)
+
+        textViewTweetCount.text = user.statusesCount.toString()
+        textViewFriendCount.text = user.friendsCount.toString()
+        textViewFollowerCount.text = user.followersCount.toString()
+        textViewFavoriteCount.text = user.favoritesCount.toString()
+
+        imageViewHeader.setImageUrl(user.profileBannerUrl, ImageCache.getImageLoader())
+    }
+
+    private fun initUserData() {
+        updateUserDataBasic()
+        updateUserDataDetail()
+
+        val activity = activity as MainActivity
+        adapter = TimelineAdapter(activity)
+        listViewTimeline.setAdapter(adapter)
+        executeUserTimelineTask(adapter)
+        updateRelationship()
+
+        observerBundle.attach(user) { changes ->
+            if (getActivity() != null) {
+                if (changes.contains(RBinding.BASIC))
+                    updateUserDataBasic()
+                if (changes.contains(RBinding.DETAIL))
+                    updateUserDataDetail()
+            }
+        }
+    }
+
+    private fun openUserMenu() {
+        val builder = AlertDialog.Builder(activity)
+        builder.setTitle("@" + user.screenName)
+                .setItems(R.array.user_commands) { dialog, which ->
+                    // XXX
+                    UIHandler().postDelayed({
+                        if (this@UserDetailDialogFragment.isAdded) {
+                            updateRelationship()
+                        }
+                    }, 1000)
+                    when (which) {
+                        0 -> {
+                            val text = String.format("@%s ", user.screenName)
+                            world.postState.beginTransaction().insertText(0, text).moveCursor(text.length).commit()
+                            world.notify(R.string.notice_add_to_reply)
+                        }
+                        1 -> DialogHelper.showDialog(activity, SendMessageDialogFragment.newInstance(user))
+                        2 -> ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands)) {
+                            Users.BlockTask(world.account, user.id)
+                                    .onDone { user -> world.notify(R.string.notice_block_succeeded) }
+                                    .onFail { ex -> world.notifyError(R.string.notice_block_failed) }
+                                    .execute()
+                        }
+                        3 -> ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands)) {
+                            Users.UnblockTask(world.account, user.id)
+                                    .onDone { user -> world.notify(R.string.notice_unblock_succeeded) }
+                                    .onFail { x -> world.notifyError(R.string.notice_unblock_failed) }
+                                    .execute()
+                        }
+                        4 -> ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_commands)) {
+                            Users.ReportForSpamTask(world.account, user.id)
+                                    .onDone { user -> world.notify(R.string.notice_r4s_succeeded) }
+                                    .onFail { ex -> world.notifyError(R.string.notice_r4s_failed) }
+                                    .execute()
+                        }
+                        5 -> IntentUtils.openUri(activity, user.aclogTimelineURL)
+                        else -> throw IllegalStateException()
+                    }
+                }
+        val dialog = builder.create()
+        dialog.show()
+    }
+
+    private fun setFollowButtonState(isFollowing: Boolean) {
+        if (activity != null) {
+            buttonFollow.state = if (isFollowing) ThreeStateButton.STATE_ON else ThreeStateButton.STATE_OFF
+        }
+    }
+
+    private fun toggleFollowing() {
+        val account = world.account
+        val isFollowing = buttonFollow.state == ThreeStateButton.STATE_ON
+        buttonFollow.state = ThreeStateButton.STATE_LOCKED
+        if (isFollowing) {
+            Users.UnfollowTask(account, user.id)
+                    .onDoneUI { result ->
+                        world.notify(R.string.notice_unfollow_succeeded)
+                        updateRelationship()
+                    }
+                    .onFail { x -> world.notifyError(R.string.notice_unfollow_failed) }
+                    .execute()
+        } else {
+            Users.FollowTask(account, user.id)
+                    .onDoneUI { result ->
+                        world.notify(R.string.notice_follow_succeeded)
+                        updateRelationship()
+                    }
+                    .onFail { x -> world.notifyError(R.string.notice_follow_failed) }
+                    .execute()
+        }
+    }
+
+    private fun updateListView(absListView: AbsListView, adapter: TimelineAdapter, addedToTop: Boolean) {
+        val before = adapter.count
+        adapter.notifyDataSetChanged() // synchronized call (not adapter#updateForce())
+        val after = adapter.count
+        val increments = after - before
+        if (increments > 0) {
+            if (addedToTop) {
+                absListView.setSelection(increments + 1)
+                absListView.smoothScrollToPositionFromTop(increments, 0)
+                absListView.setSelection(increments)
+            } else {
+                absListView.smoothScrollToPositionFromTop(before, 0)
+            }
+        }
+    }
+
+    private fun updateRelationship() {
+        val account = world.account
+        if (user === account.user) {
+            textViewFollowed.setText(R.string.user_detail_followed_is_me)
+            buttonFollow.visibility = View.GONE
+        } else {
+            buttonFollow.state = ThreeStateButton.STATE_LOCKED
+            textViewFollowed.setText(R.string.user_detail_loading)
+            Users.ShowFriendshipTask(account, user.id).onDoneUI { relationship ->
+                val isFollowing = relationship.isSourceFollowingTarget
+                val isFollowed = relationship.isSourceFollowedByTarget
+                setFollowButtonState(isFollowing)
+                textViewFollowed.setText(if (isFollowed) R.string.user_detail_followed else R.string.user_detail_not_followed)
+            }.execute()
+        }
+    }
+
+    companion object {
+        private val KEY_USER_ID = "userID"
+
+        fun newInstance(user: User): UserDetailDialogFragment {
+            val obj = UserDetailDialogFragment()
+            val bundle = Bundle()
+            bundle.putLong(KEY_USER_ID, user.id)
+            obj.arguments = bundle
+            return obj
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/listener/ListItemClickListener.java b/app/src/main/java/net/lacolaco/smileessence/view/listener/ListItemClickListener.kt
index 22d6180f..20404c63 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/listener/ListItemClickListener.java
+++ b/app/src/main/java/net/lacolaco/smileessence/view/listener/ListItemClickListener.kt
@@ -22,42 +22,35 @@
  * SOFTWARE.
  */
 
-package net.lacolaco.smileessence.view.listener;
+package net.lacolaco.smileessence.view.listener
 
-import android.app.Activity;
-import android.graphics.drawable.ColorDrawable;
-import android.support.v4.content.ContextCompat;
-import android.view.View;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.util.UIHandler;
+import android.app.Activity
+import android.graphics.drawable.ColorDrawable
+import android.support.v4.content.ContextCompat
+import android.view.View
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.util.UIHandler
 
-public class ListItemClickListener implements View.OnClickListener {
+class ListItemClickListener
+// --------------------------- CONSTRUCTORS ---------------------------
 
-    // ------------------------------ FIELDS ------------------------------
+(
+        // ------------------------------ FIELDS ------------------------------
 
-    private final Activity activity;
-    private final Runnable callback;
-
-    // --------------------------- CONSTRUCTORS ---------------------------
-
-    public ListItemClickListener(Activity activity, Runnable callback) {
-        this.activity = activity;
-        this.callback = callback;
-    }
+        private val activity: Activity, private val callback: () -> Unit) : View.OnClickListener {
 
     // ------------------------ INTERFACE METHODS ------------------------
 
 
     // --------------------- Interface OnClickListener ---------------------
 
-    @Override
-    public void onClick(final View v) {
-        final int currentBgColor = ((ColorDrawable) v.getBackground()).getColor();
-        v.setBackgroundColor(ContextCompat.getColor(activity, R.color.metro_blue));
-        v.invalidate();
-        new UIHandler().post(() -> {
-            v.setBackgroundColor(currentBgColor);
-            callback.run();
-        });
+    override fun onClick(v: View) {
+        val currentBgColor = (v.background as ColorDrawable).color
+        v.setBackgroundColor(ContextCompat.getColor(activity, R.color.metro_blue))
+        v.invalidate()
+        UIHandler().post {
+            v.setBackgroundColor(currentBgColor)
+            callback()
+        }
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.java
deleted file mode 100644
index 0dd24e67..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.java
+++ /dev/null
@@ -1,117 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.AbsListView;
-import android.widget.ListView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import com.handmark.pulltorefresh.library.PullToRefreshListView;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.view.adapter.CustomListAdapter;
-
-public abstract class CustomListFragment<T extends CustomListAdapter> extends PageFragment<T> implements AbsListView.OnScrollListener,
-        PullToRefreshBase.OnRefreshListener2<ListView> {
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.DISABLED;
-    }
-
-    // ------------------------ INTERFACE METHODS ------------------------
-
-
-    // --------------------- Interface OnRefreshListener2 ---------------------
-
-    @Override
-    public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
-    }
-
-    @Override
-    public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
-    }
-
-    // --------------------- Interface OnScrollListener ---------------------
-
-    @Override
-    public void onScrollStateChanged(AbsListView absListView, int scrollState) {
-        T adapter = getAdapter();
-        if (scrollState != SCROLL_STATE_TOUCH_SCROLL &&
-                absListView.getFirstVisiblePosition() == 0 && (absListView.getChildAt(0) == null || absListView.getChildAt(0).getTop() == 0)) {
-            adapter.setNotifiable(true);
-            updateListViewWithNotice(absListView, true);
-        } else {
-            adapter.setNotifiable(false);
-        }
-    }
-
-    @Override
-    public void onScroll(AbsListView absListView, int i, int i2, int i3) {
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        View page = inflater.inflate(R.layout.fragment_list, container, false);
-        PullToRefreshListView listView = getListView(page);
-        listView.setAdapter(getAdapter());
-        listView.setOnScrollListener(this);
-        listView.setOnRefreshListener(this);
-        listView.setMode(getRefreshMode());
-        return page;
-    }
-
-    protected PullToRefreshListView getListView(View page) {
-        return (PullToRefreshListView) page.findViewById(R.id.fragment_list_listview);
-    }
-
-    protected void updateListViewWithNotice(AbsListView absListView, boolean addedToTop) {
-        T adapter = getAdapter();
-        int before = adapter.getCount();
-        adapter.notifyDataSetChanged(); // synchronized call (not adapter#updateForce())
-        int after = adapter.getCount();
-        int increments = after - before;
-        if (increments > 0) {
-            if (addedToTop) {
-                absListView.setSelection(increments + 1);
-                absListView.smoothScrollToPositionFromTop(increments, 0);
-                absListView.setSelection(increments);
-            } else {
-                absListView.smoothScrollToPositionFromTop(before, 0);
-            }
-
-            if (increments > 1) {
-                adapter.setNotifiable(false);
-            }
-        }
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.kt
new file mode 100644
index 00000000..d8536263
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/CustomListFragment.kt
@@ -0,0 +1,107 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.AbsListView
+import android.widget.ListView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import com.handmark.pulltorefresh.library.PullToRefreshListView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.view.adapter.CustomListAdapter
+
+abstract class CustomListFragment<T : CustomListAdapter<*>> : PageFragment<T>(), AbsListView.OnScrollListener, PullToRefreshBase.OnRefreshListener2<ListView> {
+
+    // --------------------- GETTER / SETTER METHODS ---------------------
+
+    protected open val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.DISABLED
+
+    // ------------------------ INTERFACE METHODS ------------------------
+
+
+    // --------------------- Interface OnRefreshListener2 ---------------------
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {}
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {}
+
+    // --------------------- Interface OnScrollListener ---------------------
+
+    override fun onScrollStateChanged(absListView: AbsListView, scrollState: Int) {
+        val adapter = adapter
+        if (scrollState != AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL &&
+                absListView.firstVisiblePosition == 0 && (absListView.getChildAt(0) == null || absListView.getChildAt(0).top == 0)) {
+            adapter.setNotifiable(true)
+            updateListViewWithNotice(absListView, true)
+        } else {
+            adapter.setNotifiable(false)
+        }
+    }
+
+    override fun onScroll(absListView: AbsListView, i: Int, i2: Int, i3: Int) {}
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup, savedInstanceState: Bundle?): View {
+        val page = inflater.inflate(R.layout.fragment_list, container, false)
+        val listView = getListView(page)
+        listView.setAdapter(adapter)
+        listView.setOnScrollListener(this)
+        listView.setOnRefreshListener(this)
+        listView.mode = refreshMode
+        return page
+    }
+
+    protected open fun getListView(page: View): PullToRefreshListView {
+        return page.findViewById(R.id.fragment_list_listview) as PullToRefreshListView
+    }
+
+    protected fun updateListViewWithNotice(absListView: AbsListView, addedToTop: Boolean) {
+        val adapter = adapter
+        val before = adapter.count
+        adapter.notifyDataSetChanged() // synchronized call (not adapter#updateForce())
+        val after = adapter.count
+        val increments = after - before
+        if (increments > 0) {
+            if (addedToTop) {
+                absListView.setSelection(increments + 1)
+                absListView.smoothScrollToPositionFromTop(increments, 0)
+                absListView.setSelection(increments)
+            } else {
+                absListView.smoothScrollToPositionFromTop(before, 0)
+            }
+
+            if (increments > 1) {
+                adapter.setNotifiable(false)
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/HistoryFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/HistoryFragment.kt
new file mode 100644
index 00000000..70cae02f
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/HistoryFragment.kt
@@ -0,0 +1,41 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.os.Bundle
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.view.adapter.EventListAdapter
+
+class HistoryFragment : CustomListFragment<EventListAdapter>() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        adapter = EventListAdapter(world, activity)
+        world.addEventNotifier(this) { adapter.update() } // XXX
+    }
+
+    override fun refresh() {}
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.java
deleted file mode 100644
index e00f69c6..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.java
+++ /dev/null
@@ -1,104 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.os.Bundle;
-import android.widget.ListView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.twitter.task.TimelineTask;
-import net.lacolaco.smileessence.twitter.task.Timelines;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-
-public class HomeFragment extends CustomListFragment<TimelineAdapter> {
-    @Override
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.BOTH;
-    }
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        TimelineAdapter adapter = new TimelineAdapter(getActivity());
-        setAdapter(adapter);
-
-        getWorld().addTimeline(this, tweet -> {
-            adapter.add(tweet);
-            adapter.update();
-        });
-
-        refresh();
-    }
-
-    @Override
-    public void refresh() {
-        runRefreshTask(new Timelines.HomeTimelineTask(getWorld().getAccount()), () -> getAdapter().updateForce());
-    }
-
-    // --------------------- Interface OnRefreshListener2 ---------------------
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        if (getWorld().isStreaming()) {
-            new UIHandler().post(() -> {
-                updateListViewWithNotice(refreshView.getRefreshableView(), true);
-                refreshView.onRefreshComplete();
-            });
-        } else {
-            runRefreshTask(
-                    new Timelines.HomeTimelineTask(getWorld().getAccount())
-                            .setSinceId(getAdapter().getTopID()),
-                    () -> {
-                        updateListViewWithNotice(refreshView.getRefreshableView(), true);
-                        refreshView.onRefreshComplete();
-                    });
-        }
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        runRefreshTask(
-                new Timelines.HomeTimelineTask(getWorld().getAccount())
-                        .setMaxId(getAdapter().getLastID() - 1),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), false);
-                    refreshView.onRefreshComplete();
-                });
-    }
-
-    private void runRefreshTask(TimelineTask<Tweet> task, Runnable onFinish) {
-        task
-                .setCount(200)
-                .onFail(e -> getWorld().notifyError(R.string.notice_error_get_home))
-                .onDoneUI(tweets -> getWorld().addTweetAll(tweets))
-                .onFinishUI(onFinish)
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.kt
new file mode 100644
index 00000000..a9bd8fe4
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/HomeFragment.kt
@@ -0,0 +1,97 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.os.Bundle
+import android.widget.ListView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.twitter.task.TimelineTask
+import net.lacolaco.smileessence.twitter.task.Timelines
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+
+class HomeFragment : CustomListFragment<TimelineAdapter>() {
+    override val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.BOTH
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        adapter = TimelineAdapter(activity)
+
+        world.addTimeline(this) { tweet ->
+            adapter.add(tweet)
+            adapter.update()
+        }
+
+        refresh()
+    }
+
+    override fun refresh() {
+        runRefreshTask(Timelines.HomeTimelineTask(world.account), { adapter.updateForce() })
+    }
+
+    // --------------------- Interface OnRefreshListener2 ---------------------
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        if (world.isStreaming) {
+            UIHandler().post {
+                updateListViewWithNotice(refreshView.refreshableView, true)
+                refreshView.onRefreshComplete()
+            }
+        } else {
+            runRefreshTask(
+                    Timelines.HomeTimelineTask(world.account)
+                            .setSinceId(adapter.topID),
+                    {
+                        updateListViewWithNotice(refreshView.refreshableView, true)
+                        refreshView.onRefreshComplete()
+                    })
+        }
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        runRefreshTask(
+                Timelines.HomeTimelineTask(world.account)
+                        .setMaxId(adapter.lastID - 1),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, false)
+                    refreshView.onRefreshComplete()
+                })
+    }
+
+    private fun runRefreshTask(task: TimelineTask<Tweet>, onFinish: () -> Unit) {
+        task
+                .setCount(200)
+                .onFail { e -> world.notifyError(R.string.notice_error_get_home) }
+                .onDoneUI { tweets -> world.addTweetAll(tweets) }
+                .onFinishUI(onFinish)
+                .execute()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.java
deleted file mode 100644
index 21ae1169..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.java
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.os.Bundle;
-import android.widget.ListView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.data.ExtractionWord;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.entity.User;
-import net.lacolaco.smileessence.twitter.task.TimelineTask;
-import net.lacolaco.smileessence.twitter.task.Timelines;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-
-public class MentionsFragment extends CustomListFragment<TimelineAdapter> {
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    @Override
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.BOTH;
-    }
-
-    // ------------------------ INTERFACE METHODS ------------------------
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        final TimelineAdapter adapter = new TimelineAdapter(getActivity());
-        setAdapter(adapter);
-
-        // Prevent calling getWorld() on null
-        final User self = getWorld().getAccount().getUser();
-        getWorld().addTimeline(this, tweet -> {
-            if (tweet.getMentions().contains(self.getScreenName())) {
-                adapter.add(tweet);
-                adapter.update();
-            } else {
-                for (ExtractionWord word : ExtractionWord.cached()) {
-                    if (word.getPattern().matcher(tweet.getOriginalTweet().getText()).find()) {
-                        adapter.add(tweet);
-                        adapter.update();
-                    }
-                }
-            }
-        });
-
-        refresh();
-    }
-
-    @Override
-    public void refresh() {
-        runRefreshTask(new Timelines.MentionsTimelineTask(getWorld().getAccount()), () -> getAdapter().updateForce());
-    }
-
-    // --------------------- Interface OnRefreshListener2 ---------------------
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        runRefreshTask(
-                new Timelines.MentionsTimelineTask(getWorld().getAccount())
-                        .setSinceId(getAdapter().getTopID()),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), true);
-                    refreshView.onRefreshComplete();
-                });
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        runRefreshTask(
-                new Timelines.MentionsTimelineTask(getWorld().getAccount())
-                        .setMaxId(getAdapter().getLastID() - 1),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), false);
-                    refreshView.onRefreshComplete();
-                });
-    }
-
-    private void runRefreshTask(TimelineTask<Tweet> task, Runnable onFinish) {
-        task
-                .setCount(200)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_mentions))
-                .onDoneUI(tweets -> getWorld().addTweetAll(tweets))
-                .onFinishUI(onFinish)
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.kt
new file mode 100644
index 00000000..d8442ac7
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/MentionsFragment.kt
@@ -0,0 +1,102 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.os.Bundle
+import android.widget.ListView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.data.ExtractionWord
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.entity.User
+import net.lacolaco.smileessence.twitter.task.TimelineTask
+import net.lacolaco.smileessence.twitter.task.Timelines
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+
+class MentionsFragment : CustomListFragment<TimelineAdapter>() {
+    override val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.BOTH
+
+    // ------------------------ INTERFACE METHODS ------------------------
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        adapter = TimelineAdapter(activity)
+
+        // Prevent calling getWorld() on null
+        val self = world.account.user
+        world.addTimeline(this) { tweet ->
+            if (tweet.mentions.contains(self.screenName)) {
+                adapter.add(tweet)
+                adapter.update()
+            } else {
+                for (word in ExtractionWord.cached()) {
+                    if (word.pattern.matcher(tweet.originalTweet.text).find()) {
+                        adapter.add(tweet)
+                        adapter.update()
+                    }
+                }
+            }
+        }
+
+        refresh()
+    }
+
+    override fun refresh() {
+        runRefreshTask(Timelines.MentionsTimelineTask(world.account), { adapter.updateForce() })
+    }
+
+    // --------------------- Interface OnRefreshListener2 ---------------------
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        runRefreshTask(
+                Timelines.MentionsTimelineTask(world.account)
+                        .setSinceId(adapter.topID),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, true)
+                    refreshView.onRefreshComplete()
+                })
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        runRefreshTask(
+                Timelines.MentionsTimelineTask(world.account)
+                        .setMaxId(adapter.lastID - 1),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, false)
+                    refreshView.onRefreshComplete()
+                })
+    }
+
+    private fun runRefreshTask(task: TimelineTask<Tweet>, onFinish: () -> Unit) {
+        task
+                .setCount(200)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_mentions) }
+                .onDoneUI { tweets -> world.addTweetAll(tweets) }
+                .onFinishUI(onFinish)
+                .execute()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.java
deleted file mode 100644
index 291f4cfc..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.java
+++ /dev/null
@@ -1,97 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.os.Bundle;
-import android.widget.ListView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.entity.DirectMessage;
-import net.lacolaco.smileessence.twitter.task.Messages;
-import net.lacolaco.smileessence.twitter.task.TimelineTask;
-import net.lacolaco.smileessence.view.adapter.MessageListAdapter;
-
-public class MessagesFragment extends CustomListFragment<MessageListAdapter> {
-    @Override
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.BOTH;
-    }
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        MessageListAdapter adapter = new MessageListAdapter(getActivity());
-        setAdapter(adapter);
-
-        getWorld().addDirectMessageTimeline(this, message -> {
-            adapter.add(message);
-            adapter.update();
-        });
-
-        refresh();
-    }
-
-    @Override
-    public void refresh() {
-        runRefreshTask(new Messages.GetAllReceived(getWorld().getAccount()), () -> getAdapter().updateForce());
-        runRefreshTask(new Messages.GetAllSent(getWorld().getAccount()), () -> getAdapter().updateForce());
-    }
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        runRefreshTask(
-                new Messages.GetAllReceived(getWorld().getAccount())
-                        .setSinceId(getAdapter().getTopID()),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), true);
-                    refreshView.onRefreshComplete();
-                }); // TODO: sent?
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        runRefreshTask(
-                new Messages.GetAllReceived(getWorld().getAccount())
-                        .setMaxId(getAdapter().getLastID() - 1),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), false);
-                    refreshView.onRefreshComplete();
-                }); // TODO: sent?
-    }
-
-    private void runRefreshTask(TimelineTask<DirectMessage> task, Runnable onFinish) {
-        task
-                .setCount(200)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_messages))
-                .onDoneUI(messages -> {
-                    for (DirectMessage message : messages) {
-                        getWorld().addDirectMessage(message);
-                    }
-                })
-                .onFinishUI(onFinish)
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.kt
new file mode 100644
index 00000000..ea756d09
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/MessagesFragment.kt
@@ -0,0 +1,90 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.os.Bundle
+import android.widget.ListView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.entity.DirectMessage
+import net.lacolaco.smileessence.twitter.task.Messages
+import net.lacolaco.smileessence.twitter.task.TimelineTask
+import net.lacolaco.smileessence.view.adapter.MessageListAdapter
+
+class MessagesFragment : CustomListFragment<MessageListAdapter>() {
+    override val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.BOTH
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        adapter = MessageListAdapter(activity)
+
+        world.addDirectMessageTimeline(this) { message ->
+            adapter.add(message)
+            adapter.update()
+        }
+
+        refresh()
+    }
+
+    override fun refresh() {
+        runRefreshTask(Messages.GetAllReceived(world.account), { adapter.updateForce() })
+        runRefreshTask(Messages.GetAllSent(world.account), { adapter.updateForce() })
+    }
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        runRefreshTask(
+                Messages.GetAllReceived(world.account)
+                        .setSinceId(adapter.topID),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, true)
+                    refreshView.onRefreshComplete()
+                }) // TODO: sent?
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        runRefreshTask(
+                Messages.GetAllReceived(world.account)
+                        .setMaxId(adapter.lastID - 1),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, false)
+                    refreshView.onRefreshComplete()
+                }) // TODO: sent?
+    }
+
+    private fun runRefreshTask(task: TimelineTask<DirectMessage>, onFinish: () -> Unit) {
+        task
+                .setCount(200)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_messages) }
+                .onDoneUI { messages ->
+                    for (message in messages) {
+                        world.addDirectMessage(message)
+                    }
+                }
+                .onFinishUI(onFinish)
+                .execute()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.java
deleted file mode 100644
index c1299298..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package net.lacolaco.smileessence.view.page;
-
-import android.app.Fragment;
-import android.os.Bundle;
-import android.widget.Adapter;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.activity.MainActivity;
-
-public abstract class PageFragment<T extends Adapter> extends Fragment {
-    public static final String KEY_USER_ID = "KEY_USER_ID";
-    private T adapter;
-    private World world;
-
-    protected final T getAdapter() {
-        if (adapter == null) throw new IllegalStateException("adapter is not initialized");
-        return adapter;
-    }
-
-    protected final void setAdapter(T _adapter) {
-        adapter = _adapter;
-    }
-
-    public abstract void refresh();
-
-    protected final World getWorld() {
-        if (world == null) {
-            world = Application.getWorld(getArguments().getLong(KEY_USER_ID));
-        }
-        return world;
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.kt
new file mode 100644
index 00000000..596f4107
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.kt
@@ -0,0 +1,25 @@
+package net.lacolaco.smileessence.view.page
+
+import android.app.Fragment
+import android.os.Bundle
+import android.widget.Adapter
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.activity.MainActivity
+
+abstract class PageFragment<T : Adapter> : Fragment() {
+    private var _adapter: T? = null
+    protected var adapter: T
+        get() = _adapter ?: throw IllegalStateException("adapter is not initialized")
+        set(value) { _adapter = value }
+
+    protected val world: World by lazy {
+        Application.getWorld(arguments.getLong(KEY_USER_ID))
+    }
+
+    abstract fun refresh()
+
+    companion object {
+        val KEY_USER_ID = "KEY_USER_ID"
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.java
deleted file mode 100644
index c8426383..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.java
+++ /dev/null
@@ -1,334 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.content.Intent;
-import android.net.Uri;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.v4.content.ContextCompat;
-import android.text.Editable;
-import android.text.Spannable;
-import android.text.TextUtils;
-import android.text.TextWatcher;
-import android.text.method.ArrowKeyMovementMethod;
-import android.view.*;
-import android.widget.*;
-import com.twitter.Validator;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.World;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.data.PostState;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.logging.Logger;
-import net.lacolaco.smileessence.preference.UserPreferenceHelper;
-import net.lacolaco.smileessence.twitter.task.Tweets;
-import net.lacolaco.smileessence.util.BitmapThumbnailTask;
-import net.lacolaco.smileessence.util.IntentUtils;
-import net.lacolaco.smileessence.util.SystemServiceHelper;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.view.Partials;
-
-import java.io.File;
-
-public class PostFragment extends PageFragment implements TextWatcher, View.OnFocusChangeListener, View.OnClickListener,
-        PostState.OnPostStateChangeListener {
-    // ------------------------------ FIELDS ------------------------------
-
-    private EditText editText;
-    private TextView textViewCount;
-    private Button buttonTweet;
-    private ViewGroup viewGroupReply;
-    private ViewGroup viewGroupMedia;
-
-    @Override
-    public void refresh() {
-    }
-
-    // --------------------- Interface OnClickListener ---------------------
-
-    @Override
-    public void onClick(View v) {
-        switch (v.getId()) {
-            case R.id.button_post_delete: {
-                deletePost();
-                break;
-            }
-            case R.id.button_post_media: {
-                setImage();
-                break;
-            }
-            case R.id.button_post_tweet: {
-                submitPost();
-                break;
-            }
-            case R.id.button_post_reply_delete: {
-                deleteReply();
-                break;
-            }
-            case R.id.button_post_media_delete: {
-                removeImage();
-                break;
-            }
-            case R.id.image_post_media: {
-                displayImage();
-                break;
-            }
-        }
-    }
-
-    // --------------------- Interface OnFocusChangeListener ---------------------
-
-    @Override
-    public void onFocusChange(View v, boolean hasFocus) {
-        if (hasFocus) {
-            SystemServiceHelper.showIM(getActivity(), editText);
-        } else {
-            SystemServiceHelper.hideIM(getActivity(), editText);
-        }
-    }
-
-    // --------------------- Interface OnPostStateChangeListener ---------------------
-
-
-    @Override
-    public void onPostStateChange(final PostState postState) {
-        Logger.debug("onPostStateChange");
-        final MainActivity activity = (MainActivity) getActivity();
-        if (editText != null) {
-            final int start = postState.getSelectionStart();
-            final int end = postState.getSelectionEnd();
-            editText.removeTextChangedListener(this);
-            editText.setTextKeepState(postState.getText());
-            editText.addTextChangedListener(this);
-            updateTextCount(editText.getText());
-            new UIHandler().postAtFrontOfQueue(() -> editText.setSelection(start, end));
-        }
-        if (viewGroupReply != null) {
-            if (postState.getInReplyTo() != null) {
-                viewGroupReply.setVisibility(View.VISIBLE);
-                ImageButton imageButtonDeleteReply = (ImageButton) viewGroupReply.findViewById(R.id.button_post_reply_delete);
-                imageButtonDeleteReply.setOnClickListener(this);
-
-                Tweet tweet = postState.getInReplyTo();
-                View header = viewGroupReply.findViewById(R.id.layout_post_reply_status);
-                header = Partials.getTweetView(tweet, activity, header, true);
-                header.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.transparent));
-                header.setClickable(false);
-            } else {
-                viewGroupReply.setVisibility(View.GONE);
-            }
-        }
-        if (viewGroupMedia != null) {
-            ImageView imageViewMedia = (ImageView) viewGroupMedia.findViewById(R.id.image_post_media);
-            if (TextUtils.isEmpty(postState.getMediaFilePath())) {
-                viewGroupMedia.setVisibility(View.GONE);
-            } else {
-                viewGroupMedia.setVisibility(View.VISIBLE);
-
-            }
-            new BitmapThumbnailTask(postState.getMediaFilePath(), imageViewMedia).execute();
-        }
-    }
-
-    // --------------------- Interface TextWatcher ---------------------
-
-    @Override
-    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
-    }
-
-    @Override
-    public void onTextChanged(CharSequence s, int start, int before, int count) {
-        updateTextCount(s);
-    }
-
-    private void updateTextCount(CharSequence s) {
-        Validator validator = new Validator();
-        int remainingCount = 140 - validator.getTweetLength(s.toString());
-        if (!TextUtils.isEmpty(getWorld().getPostState().getMediaFilePath())) {
-            remainingCount -= validator.getShortUrlLength();
-        }
-        textViewCount.setText(String.valueOf(remainingCount));
-        if (remainingCount == 140 || remainingCount < 0) {
-            textViewCount.setTextColor(ContextCompat.getColor(getActivity(), R.color.red));
-        } else {
-            textViewCount.setTextAppearance(getActivity(), android.R.style.TextAppearance_Widget_TextView);
-        }
-        setStateFromView();
-    }
-
-    @Override
-    public void afterTextChanged(Editable s) {
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        Logger.debug("onCreate");
-        super.onCreate(savedInstanceState);
-        setHasOptionsMenu(true);
-    }
-
-    @Override
-    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
-        super.onCreateOptionsMenu(menu, inflater);
-        SystemServiceHelper.showIM(getActivity(), editText);
-    }
-
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        Logger.debug("onCreateView");
-        getWorld().getPostState().setListener(this);
-        View v = inflater.inflate(R.layout.fragment_post, null);
-        buttonTweet = getTweetButton(v);
-        buttonTweet.setOnClickListener(this);
-        editText = getEditText(v);
-        textViewCount = getCountTextView(v);
-        int textSize = UserPreferenceHelper.getInstance().getTextSize();
-        editText.addTextChangedListener(this);
-        editText.setOnFocusChangeListener(this);
-        editText.setTextSize(textSize + 4);
-        editText.setMovementMethod(new ArrowKeyMovementMethod() {
-            @Override
-            protected boolean right(@NonNull TextView widget, Spannable buffer) {
-                //Don't back to Home
-                return widget.getSelectionEnd() == widget.length() || super.right(widget, buffer);
-            }
-        });
-        ImageButton imageButtonDeleteText = (ImageButton) v.findViewById(R.id.button_post_delete);
-        imageButtonDeleteText.setOnClickListener(this);
-        ImageButton imageButtonMedia = (ImageButton) v.findViewById(R.id.button_post_media);
-        imageButtonMedia.setOnClickListener(this);
-        //Reply view
-        viewGroupReply = getReplyViewGroup(v);
-        ImageButton imageButtonDeleteReply = (ImageButton) viewGroupReply.findViewById(R.id.button_post_reply_delete);
-        imageButtonDeleteReply.setOnClickListener(this);
-        //Media view
-        viewGroupMedia = getMediaViewGroup(v);
-        ImageView imageViewMedia = (ImageView) viewGroupMedia.findViewById(R.id.image_post_media);
-        ImageButton imageButtonDeleteMedia = (ImageButton) viewGroupMedia.findViewById(R.id.button_post_media_delete);
-        imageViewMedia.setOnClickListener(this);
-        imageButtonDeleteMedia.setOnClickListener(this);
-        editText.requestFocus();
-        return v;
-    }
-
-    @Override
-    public void onDestroyView() {
-        Logger.debug("onDestroyView");
-        super.onDestroyView();
-        setStateFromView();
-        getWorld().getPostState().removeListener();
-    }
-
-    @Override
-    public void onViewStateRestored(Bundle savedInstanceState) {
-        Logger.debug("onViewStateRestored");
-        super.onViewStateRestored(savedInstanceState);
-        PostState state = getWorld().getPostState();
-        onPostStateChange(state);
-    }
-
-    private void deletePost() {
-        editText.setText("");
-        getWorld().getPostState().beginTransaction().setText("").setCursor(0).commit();
-        deleteReply();
-    }
-
-    private void deleteReply() {
-        viewGroupReply.setVisibility(View.GONE);
-        getWorld().getPostState().beginTransaction().setInReplyTo(null).commit();
-    }
-
-    private void displayImage() {
-        Intent intent = new Intent();
-        intent.setAction(Intent.ACTION_VIEW);
-        intent.addCategory(Intent.CATEGORY_DEFAULT);
-        intent.setDataAndType(Uri.fromFile(new File(getWorld().getPostState().getMediaFilePath())), "image/*");
-        IntentUtils.startActivityIfFound(getActivity(), intent);
-    }
-
-    private TextView getCountTextView(View v) {
-        return (TextView) v.findViewById(R.id.post_text_count);
-    }
-
-    private EditText getEditText(View v) {
-        return (EditText) v.findViewById(R.id.post_edit_text);
-    }
-
-    private ViewGroup getMediaViewGroup(View v) {
-        return (ViewGroup) v.findViewById(R.id.post_media_parent);
-    }
-
-    private ViewGroup getReplyViewGroup(View v) {
-        return (ViewGroup) v.findViewById(R.id.post_inreplyto_parent);
-    }
-
-    private Button getTweetButton(View v) {
-        return (Button) v.findViewById(R.id.button_post_tweet);
-    }
-
-    private void removeImage() {
-        SystemServiceHelper.hideIM(getActivity(), editText);
-        viewGroupMedia.setVisibility(View.GONE);
-        ((ImageView) viewGroupMedia.findViewById(R.id.image_post_media)).setImageBitmap(null);
-        getWorld().getPostState().beginTransaction().setMediaFilePath("").commit();
-    }
-
-    private void setImage() {
-        setStateFromView();
-        SystemServiceHelper.hideIM(getActivity(), editText);
-
-        Intent intent = new Intent(Intent.ACTION_PICK);
-        intent.setType("image/*");
-        IntentUtils.startActivityForResultIfFound(getActivity(), intent, MainActivity.REQUEST_GET_PICTURE_FROM_GALLERY);
-    }
-
-    private void setStateFromView() {
-        PostState state = getWorld().getPostState();
-        state.removeListener();
-        state.beginTransaction()
-                .setText(editText.getText().toString())
-                .setSelection(editText.getSelectionStart(), editText.getSelectionEnd())
-                .commit();
-        state.setListener(this);
-    }
-
-    private void submitPost() {
-        SystemServiceHelper.hideIM(getActivity(), editText);
-        setStateFromView();
-        PostState state = getWorld().getPostState();
-        MainActivity mainActivity = (MainActivity) getActivity();
-        boolean resizeFlag = UserPreferenceHelper.getInstance().get(R.string.key_setting_resize_post_image, false);
-        new Tweets.CreateTask(getWorld().getAccount(), state.toStatusUpdate(), state.getMediaFilePath(), resizeFlag)
-                .onDoneUI(t -> {
-                    getWorld().notify(R.string.notice_tweet_succeeded);
-                    getWorld().getPostState().beginTransaction().clear().commit();
-                })
-                .onFail(e -> getWorld().notifyError(R.string.notice_tweet_failed, e))
-                .execute();
-        mainActivity.openHomePage();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.kt
new file mode 100644
index 00000000..8afeadd1
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.kt
@@ -0,0 +1,304 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.support.v4.content.ContextCompat
+import android.text.Editable
+import android.text.Spannable
+import android.text.TextUtils
+import android.text.TextWatcher
+import android.text.method.ArrowKeyMovementMethod
+import android.view.*
+import android.widget.*
+import com.twitter.Validator
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.World
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.data.PostState
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.logging.Logger
+import net.lacolaco.smileessence.preference.UserPreferenceHelper
+import net.lacolaco.smileessence.twitter.task.Tweets
+import net.lacolaco.smileessence.util.BitmapThumbnailTask
+import net.lacolaco.smileessence.util.IntentUtils
+import net.lacolaco.smileessence.util.SystemServiceHelper
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.view.Partials
+
+import java.io.File
+
+class PostFragment : PageFragment<BaseAdapter>(), TextWatcher, View.OnFocusChangeListener, View.OnClickListener, PostState.OnPostStateChangeListener {
+    private var editText: EditText? = null
+    private var textViewCount: TextView? = null
+    private var buttonTweet: Button? = null
+    private var viewGroupReply: ViewGroup? = null
+    private var viewGroupMedia: ViewGroup? = null
+
+    override fun refresh() {}
+
+    // --------------------- Interface OnClickListener ---------------------
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.button_post_delete -> {
+                deletePost()
+            }
+            R.id.button_post_media -> {
+                setImage()
+            }
+            R.id.button_post_tweet -> {
+                submitPost()
+            }
+            R.id.button_post_reply_delete -> {
+                deleteReply()
+            }
+            R.id.button_post_media_delete -> {
+                removeImage()
+            }
+            R.id.image_post_media -> {
+                displayImage()
+            }
+        }
+    }
+
+    // --------------------- Interface OnFocusChangeListener ---------------------
+
+    override fun onFocusChange(v: View, hasFocus: Boolean) {
+        if (hasFocus) {
+            SystemServiceHelper.showIM(activity, editText)
+        } else {
+            SystemServiceHelper.hideIM(activity, editText)
+        }
+    }
+
+    // --------------------- Interface OnPostStateChangeListener ---------------------
+
+
+    override fun onPostStateChange(postState: PostState) {
+        Logger.debug("onPostStateChange")
+        val activity = activity as MainActivity
+        if (editText != null) {
+            val start = postState.selectionStart
+            val end = postState.selectionEnd
+            editText!!.removeTextChangedListener(this)
+            editText!!.setTextKeepState(postState.text)
+            editText!!.addTextChangedListener(this)
+            updateTextCount(editText!!.text)
+            UIHandler().postAtFrontOfQueue { editText!!.setSelection(start, end) }
+        }
+        if (viewGroupReply != null) {
+            if (postState.inReplyTo != null) {
+                viewGroupReply!!.visibility = View.VISIBLE
+                val imageButtonDeleteReply = viewGroupReply!!.findViewById(R.id.button_post_reply_delete) as ImageButton
+                imageButtonDeleteReply.setOnClickListener(this)
+
+                val tweet = postState.inReplyTo
+                var header = viewGroupReply!!.findViewById(R.id.layout_post_reply_status)
+                header = Partials.getTweetView(tweet!!, activity, header, true)
+                header.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.transparent))
+                header.isClickable = false
+            } else {
+                viewGroupReply!!.visibility = View.GONE
+            }
+        }
+        if (viewGroupMedia != null) {
+            val imageViewMedia = viewGroupMedia!!.findViewById(R.id.image_post_media) as ImageView
+            if (TextUtils.isEmpty(postState.mediaFilePath)) {
+                viewGroupMedia!!.visibility = View.GONE
+            } else {
+                viewGroupMedia!!.visibility = View.VISIBLE
+
+            }
+            BitmapThumbnailTask(postState.mediaFilePath, imageViewMedia).execute()
+        }
+    }
+
+    // --------------------- Interface TextWatcher ---------------------
+
+    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
+
+    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
+        updateTextCount(s)
+    }
+
+    private fun updateTextCount(s: CharSequence) {
+        val validator = Validator()
+        var remainingCount = 140 - validator.getTweetLength(s.toString())
+        if (!TextUtils.isEmpty(world.postState.mediaFilePath)) {
+            remainingCount -= validator.shortUrlLength
+        }
+        textViewCount!!.text = remainingCount.toString()
+        if (remainingCount == 140 || remainingCount < 0) {
+            textViewCount!!.setTextColor(ContextCompat.getColor(activity, R.color.red))
+        } else {
+            textViewCount!!.setTextAppearance(activity, android.R.style.TextAppearance_Widget_TextView)
+        }
+        setStateFromView()
+    }
+
+    override fun afterTextChanged(s: Editable) {}
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
+        super.onCreateOptionsMenu(menu, inflater)
+        SystemServiceHelper.showIM(activity, editText)
+    }
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
+        Logger.debug("onCreateView")
+        setHasOptionsMenu(true)
+        world.postState.setListener(this)
+        val v = inflater.inflate(R.layout.fragment_post, container, false)
+        buttonTweet = getTweetButton(v)
+        buttonTweet!!.setOnClickListener(this)
+        editText = getEditText(v)
+        textViewCount = getCountTextView(v)
+        val textSize = UserPreferenceHelper.instance.textSize
+        editText!!.addTextChangedListener(this)
+        editText!!.onFocusChangeListener = this
+        editText!!.textSize = (textSize + 4).toFloat()
+        editText!!.movementMethod = object : ArrowKeyMovementMethod() {
+            override fun right(widget: TextView, buffer: Spannable): Boolean {
+                //Don't back to Home
+                return widget.selectionEnd == widget.length() || super.right(widget, buffer)
+            }
+        }
+        val imageButtonDeleteText = v.findViewById(R.id.button_post_delete) as ImageButton
+        imageButtonDeleteText.setOnClickListener(this)
+        val imageButtonMedia = v.findViewById(R.id.button_post_media) as ImageButton
+        imageButtonMedia.setOnClickListener(this)
+        //Reply view
+        viewGroupReply = getReplyViewGroup(v)
+        val imageButtonDeleteReply = viewGroupReply!!.findViewById(R.id.button_post_reply_delete) as ImageButton
+        imageButtonDeleteReply.setOnClickListener(this)
+        //Media view
+        viewGroupMedia = getMediaViewGroup(v)
+        val imageViewMedia = viewGroupMedia!!.findViewById(R.id.image_post_media) as ImageView
+        val imageButtonDeleteMedia = viewGroupMedia!!.findViewById(R.id.button_post_media_delete) as ImageButton
+        imageViewMedia.setOnClickListener(this)
+        imageButtonDeleteMedia.setOnClickListener(this)
+        editText!!.requestFocus()
+        return v
+    }
+
+    override fun onDestroyView() {
+        Logger.debug("onDestroyView")
+        super.onDestroyView()
+        setStateFromView()
+        world.postState.removeListener()
+    }
+
+    override fun onViewStateRestored(savedInstanceState: Bundle?) {
+        Logger.debug("onViewStateRestored")
+        super.onViewStateRestored(savedInstanceState)
+        val state = world.postState
+        onPostStateChange(state)
+    }
+
+    private fun deletePost() {
+        editText!!.setText("")
+        world.postState.beginTransaction().setText("").setCursor(0).commit()
+        deleteReply()
+    }
+
+    private fun deleteReply() {
+        viewGroupReply!!.visibility = View.GONE
+        world.postState.beginTransaction().setInReplyTo(null).commit()
+    }
+
+    private fun displayImage() {
+        val intent = Intent()
+        intent.action = Intent.ACTION_VIEW
+        intent.addCategory(Intent.CATEGORY_DEFAULT)
+        intent.setDataAndType(Uri.fromFile(File(world.postState.mediaFilePath)), "image/*")
+        IntentUtils.startActivityIfFound(activity, intent)
+    }
+
+    private fun getCountTextView(v: View): TextView {
+        return v.findViewById(R.id.post_text_count) as TextView
+    }
+
+    private fun getEditText(v: View): EditText {
+        return v.findViewById(R.id.post_edit_text) as EditText
+    }
+
+    private fun getMediaViewGroup(v: View): ViewGroup {
+        return v.findViewById(R.id.post_media_parent) as ViewGroup
+    }
+
+    private fun getReplyViewGroup(v: View): ViewGroup {
+        return v.findViewById(R.id.post_inreplyto_parent) as ViewGroup
+    }
+
+    private fun getTweetButton(v: View): Button {
+        return v.findViewById(R.id.button_post_tweet) as Button
+    }
+
+    private fun removeImage() {
+        SystemServiceHelper.hideIM(activity, editText)
+        viewGroupMedia!!.visibility = View.GONE
+        (viewGroupMedia!!.findViewById(R.id.image_post_media) as ImageView).setImageBitmap(null)
+        world.postState.beginTransaction().setMediaFilePath("").commit()
+    }
+
+    private fun setImage() {
+        setStateFromView()
+        SystemServiceHelper.hideIM(activity, editText)
+
+        val intent = Intent(Intent.ACTION_PICK)
+        intent.type = "image/*"
+        IntentUtils.startActivityForResultIfFound(activity, intent, MainActivity.REQUEST_GET_PICTURE_FROM_GALLERY)
+    }
+
+    private fun setStateFromView() {
+        val state = world.postState
+        state.removeListener()
+        state.beginTransaction()
+                .setText(editText!!.text.toString())
+                .setSelection(editText!!.selectionStart, editText!!.selectionEnd)
+                .commit()
+        state.setListener(this)
+    }
+
+    private fun submitPost() {
+        SystemServiceHelper.hideIM(activity, editText)
+        setStateFromView()
+        val state = world.postState
+        val mainActivity = activity as MainActivity
+        val resizeFlag = UserPreferenceHelper.instance.get(R.string.key_setting_resize_post_image, false)
+        Tweets.CreateTask(world.account, state.toStatusUpdate(), state.mediaFilePath, resizeFlag)
+                .onDoneUI { t ->
+                    world.notify(R.string.notice_tweet_succeeded)
+                    world.postState.beginTransaction().clear().commit()
+                }
+                .onFail { e -> world.notifyError(R.string.notice_tweet_failed, e) }
+                .execute()
+        mainActivity.openHomePage()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.java
deleted file mode 100644
index 84d10c21..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.java
+++ /dev/null
@@ -1,321 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.app.AlertDialog;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.text.Spannable;
-import android.text.TextUtils;
-import android.text.method.ArrowKeyMovementMethod;
-import android.view.KeyEvent;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.view.inputmethod.EditorInfo;
-import android.widget.EditText;
-import android.widget.ImageButton;
-import android.widget.ListView;
-import android.widget.TextView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import com.handmark.pulltorefresh.library.PullToRefreshListView;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.entity.SavedSearch;
-import net.lacolaco.smileessence.preference.InternalPreferenceHelper;
-import net.lacolaco.smileessence.twitter.task.Searches;
-import net.lacolaco.smileessence.util.ListUtils;
-import net.lacolaco.smileessence.util.SystemServiceHelper;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment;
-import twitter4j.Query;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class SearchFragment extends CustomListFragment<TimelineAdapter> implements View.OnClickListener, View.OnLongClickListener,
-        View.OnFocusChangeListener {
-
-    // ------------------------------ FIELDS ------------------------------
-
-    private String queryString;
-    private TimelineAdapter adapter;
-    private EditText editText;
-
-    // --------------------- GETTER / SETTER METHODS ---------------------
-
-    @Override
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.BOTH;
-    }
-
-    // ------------------------ INTERFACE METHODS ------------------------
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setHasOptionsMenu(true);
-
-        queryString = InternalPreferenceHelper.getInstance().get(R.string.key_last_used_search_query, "");
-        android.app.Activity activity = getActivity();
-        adapter = new TimelineAdapter(activity);
-        setAdapter(adapter);
-
-        refresh();
-    }
-
-    @Override
-    public void refresh() { //TODO
-        if (!TextUtils.isEmpty(queryString)) {
-            startSearch(queryString);
-        }
-    }
-
-    // --------------------- Interface OnClickListener ---------------------
-
-    @Override
-    public void onClick(View v) {
-        switch (v.getId()) {
-            case R.id.button_search_queries: {
-                openSearchQueryDialog();
-                break;
-            }
-            case R.id.button_search_execute: {
-                search();
-                break;
-            }
-            case R.id.button_search_save: {
-                saveQuery();
-            }
-        }
-    }
-
-    @Override
-    public boolean onLongClick(View v) {
-        switch (v.getId()) {
-            case R.id.button_search_save: {
-                String text = editText.getText().toString();
-                for (SavedSearch ss : getWorld().getSavedSearches()) {
-                    if (ss.getQuery().equals(text)) {
-                        ConfirmDialogFragment.show(getActivity(), getString(R.string.dialog_confirm_delete_query), () -> new Searches.DestroySavedSearchTask(getWorld().getAccount(), ss.getId())
-                                .onDoneUI(x -> {
-                                    getWorld().notify(R.string.notice_search_query_deleted);
-                                    getWorld().refreshSavedSearches();
-                                })
-                                .onFailUI(x -> getWorld().notify("unable to delete search query"))
-                                .execute(), false);
-                        break;
-                    }
-                }
-                return true;
-            }
-        }
-        return false;
-    }
-
-    // --------------------- Interface OnFocusChangeListener ---------------------
-
-    @Override
-    public void onFocusChange(View v, boolean hasFocus) {
-        if (!hasFocus) {
-            SystemServiceHelper.hideIM(getActivity(), editText);
-        }
-    }
-
-    // --------------------- Interface OnRefreshListener2 ---------------------
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        if (TextUtils.isEmpty(queryString)) {
-            new UIHandler().post(() -> {
-                notifyTextEmpty();
-                refreshView.onRefreshComplete();
-            });
-            return;
-        }
-        final Query query = new Query();
-        query.setQuery(queryString);
-        query.setCount(200);
-        query.setResultType(Query.RECENT);
-        if (adapter.getCount() > 0) {
-            query.setSinceId(adapter.getTopID());
-        }
-        runRefreshTask(query, () -> {
-            updateListViewWithNotice(refreshView.getRefreshableView(), true);
-            refreshView.onRefreshComplete();
-        });
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        if (TextUtils.isEmpty(queryString)) {
-            new UIHandler().post(() -> {
-                notifyTextEmpty();
-                refreshView.onRefreshComplete();
-            });
-            return;
-        }
-        final Query query = new Query();
-        query.setQuery(queryString);
-        query.setCount(200);
-        query.setResultType(Query.RECENT);
-        if (adapter.getCount() > 0) {
-            query.setMaxId(adapter.getLastID() - 1);
-        }
-        runRefreshTask(query, () -> {
-            updateListViewWithNotice(refreshView.getRefreshableView(), false);
-            refreshView.onRefreshComplete();
-        });
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    protected PullToRefreshListView getListView(View page) {
-        return (PullToRefreshListView) page.findViewById(R.id.listview_search);
-    }
-
-    @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        View page = inflater.inflate(R.layout.fragment_search, container, false);
-        PullToRefreshListView listView = getListView(page);
-        listView.setAdapter(adapter);
-        listView.setOnScrollListener(this);
-        listView.setOnRefreshListener(this);
-        listView.setMode(getRefreshMode());
-        ImageButton buttonQueries = getQueriesButton(page);
-        buttonQueries.setOnClickListener(this);
-        ImageButton buttonExecute = getExecuteButton(page);
-        buttonExecute.setOnClickListener(this);
-        ImageButton buttonSave = getSaveButton(page);
-        buttonSave.setOnClickListener(this);
-        editText = getEditText(page);
-        editText.setOnFocusChangeListener(this);
-        editText.setText(queryString);
-        editText.setOnEditorActionListener((textView, i, keyEvent) -> {
-            if (i == EditorInfo.IME_ACTION_SEARCH ||
-                    keyEvent != null &&
-                            keyEvent.getAction() == KeyEvent.ACTION_DOWN &&
-                            keyEvent.getKeyCode() == KeyEvent.KEYCODE_ENTER) {
-                search();
-            }
-            return true;
-        });
-        editText.setMovementMethod(new ArrowKeyMovementMethod() {
-            @Override
-            protected boolean right(@NonNull TextView widget, Spannable buffer) {
-                //Don't move page
-                return widget.getSelectionEnd() == widget.length() || super.right(widget, buffer);
-            }
-
-            @Override
-            protected boolean left(@NonNull TextView widget, Spannable buffer) {
-                //Don't move page
-                return widget.getSelectionStart() == 0 || super.left(widget, buffer);
-            }
-        });
-        return page;
-    }
-
-    private EditText getEditText(View page) {
-        return (EditText) page.findViewById(R.id.edittext_search);
-    }
-
-    private ImageButton getExecuteButton(View page) {
-        return (ImageButton) page.findViewById(R.id.button_search_execute);
-    }
-
-    private ImageButton getQueriesButton(View page) {
-        return (ImageButton) page.findViewById(R.id.button_search_queries);
-    }
-
-    private ImageButton getSaveButton(View page) {
-        return (ImageButton) page.findViewById(R.id.button_search_save);
-    }
-
-    private void notifyTextEmpty() {
-        getWorld().notifyError(R.string.notice_search_text_empty);
-    }
-
-    private void openSearchQueryDialog() {
-        List<SavedSearch> sss = new ArrayList<>(getWorld().getSavedSearches());
-        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
-        builder.setItems(ListUtils.map(sss, SavedSearch::getQuery).toArray(new String[]{}), (dialog, which) -> {
-            SavedSearch ss = sss.get(which);
-            ((MainActivity) getActivity()).openSearchPage(ss.getQuery());
-        });
-        AlertDialog dialog = builder.create();
-        dialog.show();
-    }
-
-    private void saveQuery() {
-        String text = editText.getText().toString();
-        if (TextUtils.isEmpty(text)) {
-            getWorld().notifyError(R.string.notice_query_is_empty);
-        } else {
-            new Searches.CreateSavedSearchTask(getWorld().getAccount(), text).onDoneUI(cb -> {
-                getWorld().notify(R.string.notice_query_saved);
-                getWorld().refreshSavedSearches();
-            }).onFailUI(ex -> getWorld().notifyError("Query is not saved")).execute();
-        }
-    }
-
-    private void search() {
-        if (editText != null) {
-            String text = editText.getText().toString();
-            if (TextUtils.isEmpty(text)) {
-                getWorld().notifyError(R.string.notice_query_is_empty);
-            } else {
-                startSearch(text);
-                SystemServiceHelper.hideIM(getActivity(), editText);
-            }
-        }
-    }
-
-    public void startSearch(final String queryString) {
-        InternalPreferenceHelper.getInstance().set(R.string.key_last_used_search_query, queryString);
-        if (editText != null)
-            editText.setText(queryString);
-        this.queryString = queryString;
-        adapter.clear();
-        adapter.updateForce();
-        if (!TextUtils.isEmpty(queryString)) {
-            final Query query = new Query();
-            query.setQuery(queryString);
-            query.setCount(200);
-            query.setResultType(Query.RECENT);
-            runRefreshTask(query, adapter::updateForce);
-        }
-    }
-
-    private void runRefreshTask(Query query, Runnable onFinish) {
-        new Searches.SearchTask(getWorld().getAccount(), query)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_search))
-                .onDoneUI(tweets -> adapter.addAll(ListUtils.filter(tweets, t -> !t.isRetweet())))
-                .onFinishUI(onFinish)
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.kt
new file mode 100644
index 00000000..de06a133
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/SearchFragment.kt
@@ -0,0 +1,299 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.app.AlertDialog
+import android.os.Bundle
+import android.text.Spannable
+import android.text.TextUtils
+import android.text.method.ArrowKeyMovementMethod
+import android.view.KeyEvent
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.view.inputmethod.EditorInfo
+import android.widget.EditText
+import android.widget.ImageButton
+import android.widget.ListView
+import android.widget.TextView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import com.handmark.pulltorefresh.library.PullToRefreshListView
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.preference.InternalPreferenceHelper
+import net.lacolaco.smileessence.twitter.task.Searches
+import net.lacolaco.smileessence.util.SystemServiceHelper
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+import net.lacolaco.smileessence.view.dialog.ConfirmDialogFragment
+import twitter4j.Query
+
+import java.util.ArrayList
+
+class SearchFragment : CustomListFragment<TimelineAdapter>(), View.OnClickListener, View.OnLongClickListener, View.OnFocusChangeListener {
+
+    // ------------------------------ FIELDS ------------------------------
+
+    private lateinit var queryString: String
+    private var editText: EditText? = null
+
+    // --------------------- GETTER / SETTER METHODS ---------------------
+
+    override val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.BOTH
+
+    // ------------------------ INTERFACE METHODS ------------------------
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setHasOptionsMenu(true)
+
+        queryString = InternalPreferenceHelper.instance.get(R.string.key_last_used_search_query, "")
+        adapter = TimelineAdapter(activity)
+
+        refresh()
+    }
+
+    override fun refresh() { //TODO
+        if (!TextUtils.isEmpty(queryString)) {
+            startSearch(queryString)
+        }
+    }
+
+    // --------------------- Interface OnClickListener ---------------------
+
+    override fun onClick(v: View) {
+        when (v.id) {
+            R.id.button_search_queries -> {
+                openSearchQueryDialog()
+            }
+            R.id.button_search_execute -> {
+                search()
+            }
+            R.id.button_search_save -> {
+                saveQuery()
+            }
+        }
+    }
+
+    override fun onLongClick(v: View): Boolean {
+        when (v.id) {
+            R.id.button_search_save -> {
+                val text = editText!!.text.toString()
+                for (ss in world.savedSearches.values) {
+                    if (ss.query == text) {
+                        ConfirmDialogFragment.show(activity, getString(R.string.dialog_confirm_delete_query), {
+                            Searches.DestroySavedSearchTask(world.account, ss.id)
+                                    .onDoneUI { x ->
+                                        world.notify(R.string.notice_search_query_deleted)
+                                        world.refreshSavedSearches()
+                                    }
+                                    .onFailUI { x -> world.notify("unable to delete search query") }
+                                    .execute()
+                        }, false)
+                        break
+                    }
+                }
+                return true
+            }
+        }
+        return false
+    }
+
+    // --------------------- Interface OnFocusChangeListener ---------------------
+
+    override fun onFocusChange(v: View, hasFocus: Boolean) {
+        if (!hasFocus) {
+            SystemServiceHelper.hideIM(activity, editText)
+        }
+    }
+
+    // --------------------- Interface OnRefreshListener2 ---------------------
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        if (TextUtils.isEmpty(queryString)) {
+            UIHandler().post {
+                notifyTextEmpty()
+                refreshView.onRefreshComplete()
+            }
+            return
+        }
+        val query = Query()
+        query.query = queryString
+        query.count = 200
+        query.resultType = Query.RECENT
+        if (adapter.count > 0) {
+            query.sinceId = adapter.topID
+        }
+        runRefreshTask(query, {
+            updateListViewWithNotice(refreshView.refreshableView, true)
+            refreshView.onRefreshComplete()
+        })
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        if (TextUtils.isEmpty(queryString)) {
+            UIHandler().post {
+                notifyTextEmpty()
+                refreshView.onRefreshComplete()
+            }
+            return
+        }
+        val query = Query()
+        query.query = queryString
+        query.count = 200
+        query.resultType = Query.RECENT
+        if (adapter.count > 0) {
+            query.maxId = adapter.lastID - 1
+        }
+        runRefreshTask(query, {
+            updateListViewWithNotice(refreshView.refreshableView, false)
+            refreshView.onRefreshComplete()
+        })
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun getListView(page: View): PullToRefreshListView {
+        return page.findViewById(R.id.listview_search) as PullToRefreshListView
+    }
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup, savedInstanceState: Bundle?): View {
+        val page = inflater.inflate(R.layout.fragment_search, container, false)
+        val listView = getListView(page)
+        listView.setAdapter(adapter)
+        listView.setOnScrollListener(this)
+        listView.setOnRefreshListener(this)
+        listView.mode = refreshMode
+        val buttonQueries = getQueriesButton(page)
+        buttonQueries.setOnClickListener(this)
+        val buttonExecute = getExecuteButton(page)
+        buttonExecute.setOnClickListener(this)
+        val buttonSave = getSaveButton(page)
+        buttonSave.setOnClickListener(this)
+        editText = getEditText(page)
+        editText!!.onFocusChangeListener = this
+        editText!!.setText(queryString)
+        editText!!.setOnEditorActionListener { textView, i, keyEvent ->
+            if (i == EditorInfo.IME_ACTION_SEARCH || keyEvent != null &&
+                    keyEvent.action == KeyEvent.ACTION_DOWN &&
+                    keyEvent.keyCode == KeyEvent.KEYCODE_ENTER) {
+                search()
+            }
+            true
+        }
+        editText!!.movementMethod = object : ArrowKeyMovementMethod() {
+            override fun right(widget: TextView, buffer: Spannable): Boolean {
+                //Don't move page
+                return widget.selectionEnd == widget.length() || super.right(widget, buffer)
+            }
+
+            override fun left(widget: TextView, buffer: Spannable): Boolean {
+                //Don't move page
+                return widget.selectionStart == 0 || super.left(widget, buffer)
+            }
+        }
+        return page
+    }
+
+    private fun getEditText(page: View): EditText {
+        return page.findViewById(R.id.edittext_search) as EditText
+    }
+
+    private fun getExecuteButton(page: View): ImageButton {
+        return page.findViewById(R.id.button_search_execute) as ImageButton
+    }
+
+    private fun getQueriesButton(page: View): ImageButton {
+        return page.findViewById(R.id.button_search_queries) as ImageButton
+    }
+
+    private fun getSaveButton(page: View): ImageButton {
+        return page.findViewById(R.id.button_search_save) as ImageButton
+    }
+
+    private fun notifyTextEmpty() {
+        world.notifyError(R.string.notice_search_text_empty)
+    }
+
+    private fun openSearchQueryDialog() {
+        val sss = ArrayList(world.savedSearches.values)
+        val builder = AlertDialog.Builder(activity)
+        builder.setItems(sss.map { it.query }.toTypedArray()) { dialog, which ->
+            val ss = sss[which]
+            (activity as MainActivity).openSearchPage(ss.query)
+        }
+        val dialog = builder.create()
+        dialog.show()
+    }
+
+    private fun saveQuery() {
+        val text = editText!!.text.toString()
+        if (TextUtils.isEmpty(text)) {
+            world.notifyError(R.string.notice_query_is_empty)
+        } else {
+            Searches.CreateSavedSearchTask(world.account, text).onDoneUI { cb ->
+                world.notify(R.string.notice_query_saved)
+                world.refreshSavedSearches()
+            }.onFailUI { ex -> world.notifyError("Query is not saved") }.execute()
+        }
+    }
+
+    private fun search() {
+        if (editText != null) {
+            val text = editText!!.text.toString()
+            if (TextUtils.isEmpty(text)) {
+                world.notifyError(R.string.notice_query_is_empty)
+            } else {
+                startSearch(text)
+                SystemServiceHelper.hideIM(activity, editText)
+            }
+        }
+    }
+
+    fun startSearch(queryString: String) {
+        InternalPreferenceHelper.instance.set(R.string.key_last_used_search_query, queryString)
+        if (editText != null)
+            editText!!.setText(queryString)
+        this.queryString = queryString
+        adapter.clear()
+        adapter.updateForce()
+        if (!TextUtils.isEmpty(queryString)) {
+            val query = Query()
+            query.query = queryString
+            query.count = 200
+            query.resultType = Query.RECENT
+            runRefreshTask(query) { adapter.updateForce() }
+        }
+    }
+
+    private fun runRefreshTask(query: Query, onFinish: () -> Unit) {
+        Searches.SearchTask(world.account, query)
+                .onFail { x -> world.notifyError(R.string.notice_error_search) }
+                .onDoneUI { tweets -> adapter.addAll(tweets.filter { t -> !t.isRetweet }) }
+                .onFinishUI(onFinish)
+                .execute()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.java b/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.java
deleted file mode 100644
index 3d19c5d6..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.java
+++ /dev/null
@@ -1,192 +0,0 @@
-/*
- * The MIT License (MIT)
- *
- * Copyright (c) 2012-2014 lacolaco.net
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.lacolaco.smileessence.view.page;
-
-import android.app.AlertDialog;
-import android.os.Bundle;
-import android.text.TextUtils;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ImageButton;
-import android.widget.ListView;
-import android.widget.TextView;
-import com.handmark.pulltorefresh.library.PullToRefreshBase;
-import com.handmark.pulltorefresh.library.PullToRefreshListView;
-import net.lacolaco.smileessence.Application;
-import net.lacolaco.smileessence.R;
-import net.lacolaco.smileessence.activity.MainActivity;
-import net.lacolaco.smileessence.entity.Tweet;
-import net.lacolaco.smileessence.preference.InternalPreferenceHelper;
-import net.lacolaco.smileessence.twitter.task.TimelineTask;
-import net.lacolaco.smileessence.twitter.task.Timelines;
-import net.lacolaco.smileessence.util.UIHandler;
-import net.lacolaco.smileessence.view.adapter.TimelineAdapter;
-
-public class UserListFragment extends CustomListFragment<TimelineAdapter> implements View.OnClickListener {
-    private TextView textListName;
-    private String listFullName;
-
-    @Override
-    protected PullToRefreshBase.Mode getRefreshMode() {
-        return PullToRefreshBase.Mode.BOTH;
-    }
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        TimelineAdapter adapter = new TimelineAdapter(getActivity());
-        setAdapter(adapter);
-
-        refresh();
-    }
-
-    @Override
-    public void refresh() {//TODO
-        String lastUserList = InternalPreferenceHelper.getInstance().get(R.string.key_last_used_user_list, "");
-        if (!TextUtils.isEmpty(lastUserList)) {
-            startUserList(lastUserList);
-        }
-    }
-
-    @Override
-    public void onClick(View v) {
-        int id = v.getId();
-        switch (id) {
-            case R.id.button_userlist_lists: {
-                openUserListsDialog();
-                break;
-            }
-        }
-    }
-
-    @Override
-    public void onPullDownToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        if (listFullName == null) {
-            new UIHandler().post(() -> {
-                notifyTextEmpty();
-                refreshView.onRefreshComplete();
-            });
-            return;
-        }
-        runRefreshTask(
-                new Timelines.UserListStatusesTask(getWorld().getAccount(), listFullName)
-                        .setSinceId(getAdapter().getTopID()),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), true);
-                    refreshView.onRefreshComplete();
-                });
-    }
-
-    @Override
-    public void onPullUpToRefresh(final PullToRefreshBase<ListView> refreshView) {
-        if (listFullName == null) {
-            new UIHandler().post(() -> {
-                notifyTextEmpty();
-                refreshView.onRefreshComplete();
-            });
-            return;
-        }
-        runRefreshTask(
-                new Timelines.UserListStatusesTask(getWorld().getAccount(), listFullName)
-                        .setMaxId(getAdapter().getLastID() - 1),
-                () -> {
-                    updateListViewWithNotice(refreshView.getRefreshableView(), false);
-                    refreshView.onRefreshComplete();
-                });
-    }
-
-    // ------------------------ OVERRIDE METHODS ------------------------
-
-    @Override
-    protected PullToRefreshListView getListView(View page) {
-        return (PullToRefreshListView) page.findViewById(R.id.listview_userlist);
-    }
-
-    @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        View page = inflater.inflate(R.layout.fragment_userlist, container, false);
-        PullToRefreshListView listView = getListView(page);
-        TimelineAdapter adapter = getAdapter();
-        listView.setAdapter(adapter);
-        listView.setOnScrollListener(this);
-        listView.setOnRefreshListener(this);
-        listView.setMode(getRefreshMode());
-        ImageButton buttonUserLists = getUserListsButton(page);
-        buttonUserLists.setOnClickListener(this);
-        textListName = getTextListName(page);
-        textListName.setText(listFullName != null ? listFullName : "<none>");
-        return page;
-    }
-
-    private TextView getTextListName(View page) {
-        return (TextView) page.findViewById(R.id.textview_userlist_name);
-    }
-
-    private ImageButton getUserListsButton(View page) {
-        return (ImageButton) page.findViewById(R.id.button_userlist_lists);
-    }
-
-    private void notifyTextEmpty() {
-        getWorld().notifyError(R.string.notice_userlist_not_selected);
-    }
-
-    private void openUserListsDialog() {
-        final String[] ary = getWorld().getListSubscriptions().toArray(new String[]{});
-        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
-        builder.setTitle(R.string.dialog_title_select_userlist)
-                .setItems(ary, (dialog, which) -> {
-                    MainActivity activity = (MainActivity) getActivity();
-                    activity.openUserListPage(ary[which]);
-                    textListName.setText(ary[which]);
-                });
-        AlertDialog dialog = builder.create();
-        dialog.show();
-    }
-
-    public void startUserList(String listFullName) {
-        InternalPreferenceHelper.getInstance().set(R.string.key_last_used_user_list, listFullName);
-        final TimelineAdapter adapter = getAdapter();
-        this.listFullName = listFullName;
-        adapter.clear();
-        adapter.updateForce();
-        runRefreshTask(
-                new Timelines.UserListStatusesTask(getWorld().getAccount(), listFullName),
-                adapter::updateForce);
-    }
-
-    private void runRefreshTask(TimelineTask<Tweet> task, Runnable onFinish) {
-        final TimelineAdapter adapter = getAdapter();
-        task
-                .setCount(200)
-                .onFail(x -> getWorld().notifyError(R.string.notice_error_get_list))
-                .onDoneUI(tweets -> {
-                    getWorld().addTweetAll(tweets);
-                    adapter.addAll(tweets);
-                })
-                .onFinishUI(onFinish)
-                .execute();
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.kt b/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.kt
new file mode 100644
index 00000000..3fb7ef49
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.kt
@@ -0,0 +1,179 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2012-2014 lacolaco.net
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.lacolaco.smileessence.view.page
+
+import android.app.AlertDialog
+import android.os.Bundle
+import android.text.TextUtils
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageButton
+import android.widget.ListView
+import android.widget.TextView
+import com.handmark.pulltorefresh.library.PullToRefreshBase
+import com.handmark.pulltorefresh.library.PullToRefreshListView
+import net.lacolaco.smileessence.Application
+import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.preference.InternalPreferenceHelper
+import net.lacolaco.smileessence.twitter.task.TimelineTask
+import net.lacolaco.smileessence.twitter.task.Timelines
+import net.lacolaco.smileessence.util.UIHandler
+import net.lacolaco.smileessence.view.adapter.TimelineAdapter
+
+class UserListFragment : CustomListFragment<TimelineAdapter>(), View.OnClickListener {
+    private var textListName: TextView? = null
+    private var listFullName: String? = null
+
+    override val refreshMode: PullToRefreshBase.Mode
+        get() = PullToRefreshBase.Mode.BOTH
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        adapter = TimelineAdapter(activity)
+
+        refresh()
+    }
+
+    override fun refresh() {//TODO
+        val lastUserList = InternalPreferenceHelper.instance.get(R.string.key_last_used_user_list, "")
+        if (!TextUtils.isEmpty(lastUserList)) {
+            startUserList(lastUserList)
+        }
+    }
+
+    override fun onClick(v: View) {
+        val id = v.id
+        when (id) {
+            R.id.button_userlist_lists -> {
+                openUserListsDialog()
+            }
+        }
+    }
+
+    override fun onPullDownToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        if (listFullName == null) {
+            UIHandler().post {
+                notifyTextEmpty()
+                refreshView.onRefreshComplete()
+            }
+            return
+        }
+        runRefreshTask(
+                Timelines.UserListStatusesTask(world.account, listFullName!!)
+                        .setSinceId(adapter.topID),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, true)
+                    refreshView.onRefreshComplete()
+                })
+    }
+
+    override fun onPullUpToRefresh(refreshView: PullToRefreshBase<ListView>) {
+        if (listFullName == null) {
+            UIHandler().post {
+                notifyTextEmpty()
+                refreshView.onRefreshComplete()
+            }
+            return
+        }
+        runRefreshTask(
+                Timelines.UserListStatusesTask(world.account, listFullName!!)
+                        .setMaxId(adapter.lastID - 1),
+                {
+                    updateListViewWithNotice(refreshView.refreshableView, false)
+                    refreshView.onRefreshComplete()
+                })
+    }
+
+    // ------------------------ OVERRIDE METHODS ------------------------
+
+    override fun getListView(page: View): PullToRefreshListView {
+        return page.findViewById(R.id.listview_userlist) as PullToRefreshListView
+    }
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup, savedInstanceState: Bundle?): View {
+        val page = inflater.inflate(R.layout.fragment_userlist, container, false)
+        val listView = getListView(page)
+        val adapter = adapter
+        listView.setAdapter(adapter)
+        listView.setOnScrollListener(this)
+        listView.setOnRefreshListener(this)
+        listView.mode = refreshMode
+        val buttonUserLists = getUserListsButton(page)
+        buttonUserLists.setOnClickListener(this)
+        textListName = getTextListName(page)
+        textListName!!.text = if (listFullName != null) listFullName else "<none>"
+        return page
+    }
+
+    private fun getTextListName(page: View): TextView {
+        return page.findViewById(R.id.textview_userlist_name) as TextView
+    }
+
+    private fun getUserListsButton(page: View): ImageButton {
+        return page.findViewById(R.id.button_userlist_lists) as ImageButton
+    }
+
+    private fun notifyTextEmpty() {
+        world.notifyError(R.string.notice_userlist_not_selected)
+    }
+
+    private fun openUserListsDialog() {
+        val ary = world.listSubscriptions.toTypedArray<String>()
+        val builder = AlertDialog.Builder(activity)
+        builder.setTitle(R.string.dialog_title_select_userlist)
+                .setItems(ary) { dialog, which ->
+                    val activity = activity as MainActivity
+                    activity.openUserListPage(ary[which])
+                    textListName!!.text = ary[which]
+                }
+        val dialog = builder.create()
+        dialog.show()
+    }
+
+    fun startUserList(listFullName: String) {
+        InternalPreferenceHelper.instance.set(R.string.key_last_used_user_list, listFullName)
+        val adapter = adapter
+        this.listFullName = listFullName
+        adapter.clear()
+        adapter.updateForce()
+        runRefreshTask(Timelines.UserListStatusesTask(world.account, listFullName)) { adapter.updateForce() }
+    }
+
+    private fun runRefreshTask(task: TimelineTask<Tweet>, onFinish: () -> Unit) {
+        val adapter = adapter
+        task
+                .setCount(200)
+                .onFail { x -> world.notifyError(R.string.notice_error_get_list) }
+                .onDoneUI { tweets ->
+                    world.addTweetAll(tweets)
+                    adapter.addAll(tweets)
+                }
+                .onFinishUI(onFinish)
+                .execute()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.java b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.java
deleted file mode 100644
index 88ad0879..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package net.lacolaco.smileessence.view.preference;
-
-import android.annotation.TargetApi;
-import android.content.Context;
-import android.os.Build;
-import android.preference.EditTextPreference;
-import android.util.AttributeSet;
-
-public class IntegerEditTextPreference extends EditTextPreference {
-    public IntegerEditTextPreference(Context context) {
-        super(context);
-    }
-
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    public IntegerEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
-    }
-
-    public IntegerEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-    }
-
-    public IntegerEditTextPreference(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    @Override
-    protected boolean persistString(String value) {
-        return persistInt(Integer.valueOf(value));
-    }
-
-    @Override
-    protected String getPersistedString(String defaultReturnValue) {
-        return String.valueOf(getPersistedInt(-1));
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.kt b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.kt
new file mode 100644
index 00000000..e6a23696
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerEditTextPreference.kt
@@ -0,0 +1,26 @@
+package net.lacolaco.smileessence.view.preference
+
+import android.annotation.TargetApi
+import android.content.Context
+import android.os.Build
+import android.preference.EditTextPreference
+import android.util.AttributeSet
+
+class IntegerEditTextPreference : EditTextPreference {
+    constructor(context: Context) : super(context)
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int) : super(context, attrs, defStyleAttr, defStyleRes)
+
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
+
+    override fun persistString(value: String): Boolean {
+        return persistInt(Integer.valueOf(value)!!)
+    }
+
+    override fun getPersistedString(defaultReturnValue: String?): String {
+        return getPersistedInt(-1).toString()
+    }
+}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.java b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.java
deleted file mode 100644
index f04a3b89..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package net.lacolaco.smileessence.view.preference;
-
-import android.annotation.TargetApi;
-import android.content.Context;
-import android.os.Build;
-import android.preference.ListPreference;
-import android.util.AttributeSet;
-
-public class IntegerListPreference extends ListPreference {
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    public IntegerListPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
-    }
-
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    public IntegerListPreference(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-    }
-
-    public IntegerListPreference(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    public IntegerListPreference(Context context) {
-        super(context);
-    }
-
-    @Override
-    protected boolean persistString(String value) {
-        return persistInt(Integer.valueOf(value));
-    }
-
-    @Override
-    protected String getPersistedString(String defaultReturnValue) {
-        return String.valueOf(getPersistedInt(-1));
-    }
-}
diff --git a/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.kt b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.kt
new file mode 100644
index 00000000..7dbe3297
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/preference/IntegerListPreference.kt
@@ -0,0 +1,27 @@
+package net.lacolaco.smileessence.view.preference
+
+import android.annotation.TargetApi
+import android.content.Context
+import android.os.Build
+import android.preference.ListPreference
+import android.util.AttributeSet
+
+class IntegerListPreference : ListPreference {
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int) : super(context, attrs, defStyleAttr, defStyleRes)
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
+
+    constructor(context: Context) : super(context)
+
+    override fun persistString(value: String): Boolean {
+        return persistInt(Integer.valueOf(value)!!)
+    }
+
+    override fun getPersistedString(defaultReturnValue: String?): String {
+        return getPersistedInt(-1).toString()
+    }
+}
diff --git a/build.gradle b/build.gradle
index a3ca24b9..06ebf25f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    ext.kotlin_version = '1.1.51'
     repositories {
         jcenter()
         mavenCentral()
@@ -10,6 +11,7 @@ buildscript {
         classpath 'com.android.tools.build:gradle:2.3.0'
         classpath 'me.tatarka:gradle-retrolambda:3.7.0'
         classpath 'io.fabric.tools:gradle:1.+'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }