poststate moved to postfragmetn

13 files changed, 278 insertions, 453 deletions

diff --git a/app/build.gradle b/app/build.gradle
index 4192c6e2..082033f9 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -32,6 +32,9 @@ android {
             applicationIdSuffix ".release"
         }
     }
+    androidExtensions {
+        experimental = true
+    }
 }
 
 repositories {
diff --git a/app/licenses.yml b/app/licenses.yml
index 3294e321..4bcfa3aa 100644
--- a/app/licenses.yml
+++ b/app/licenses.yml
@@ -12,6 +12,10 @@
   license: The Apache License, Version 2.0
 - artifact: org.jetbrains.kotlinx:kotlinx-coroutines-android:+
   skip: true
+- artifact: org.jetbrains.kotlin:kotlin-android-extensions-runtime:+
+  name: kotlin-android-extensions-runtime
+  copyrightHolder: JetBrains s.r.o.
+  license: The Apache License, Version 2.0
 - artifact: com.android.support:+:+
   name: Android Support Libraries
   copyrightHolder: The Android Open Source Project
diff --git a/app/src/main/java/net/lacolaco/smileessence/World.kt b/app/src/main/java/net/lacolaco/smileessence/World.kt
index 4c38c653..e74c9fa8 100644
--- a/app/src/main/java/net/lacolaco/smileessence/World.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/World.kt
@@ -7,7 +7,6 @@ import kotlinx.android.synthetic.main.layout_main.*
 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
@@ -30,10 +29,7 @@ import java.util.concurrent.ConcurrentHashMap
  * World contains data that are specific to an account.
  */
 class World(val account: Account) {
-    // XXX: Move to MainActivity
-    val postState = PostState()
     // XXX: Workaround for a bug in Android
-    @Deprecated("A temporary workaround")
     var mainActivityIntent: Intent? = null
     // Timelines
     private val tweets = ArrayList<Tweet>()
diff --git a/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt b/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt
index b286003a..d738d6b4 100644
--- a/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/activity/MainActivity.kt
@@ -20,13 +20,15 @@ import net.lacolaco.smileessence.Application
 import net.lacolaco.smileessence.R
 import net.lacolaco.smileessence.World
 import net.lacolaco.smileessence.data.ExtractionWord
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.entity.User
 import net.lacolaco.smileessence.logging.Logger
 import net.lacolaco.smileessence.twitter.TwitterTaskException
 import net.lacolaco.smileessence.twitter.task.getTweetAsync
 import net.lacolaco.smileessence.twitter.task.getUserAsync
 import net.lacolaco.smileessence.util.*
 import net.lacolaco.smileessence.view.DialogHelper
-import net.lacolaco.smileessence.view.adapter.PageListAdapter
+import net.lacolaco.smileessence.view.MainFragmentPagerAdapter
 import net.lacolaco.smileessence.view.confirm
 import net.lacolaco.smileessence.view.dialog.StatusDetailDialogFragment
 import net.lacolaco.smileessence.view.dialog.UserDetailDialogFragment
@@ -42,18 +44,32 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
         val userIdValue = uri.getQueryParameter("user_id") ?: throw IllegalStateException("[BUG] user_id not set")
         Application.getWorld(userIdValue.toLong())
     }
-    private val pagerAdapter by lazy { PageListAdapter(this) }
+    private lateinit var pagerAdapter: MainFragmentPagerAdapter
+
+    fun openHomePage() {
+        viewPager.setCurrentItem(pagerAdapter.getPageIndex(TAG_PAGE_HOME), true)
+    }
 
     private fun setSelectedPageIndex(position: Int, smooth: Boolean = true) {
         viewPager.setCurrentItem(position, smooth)
     }
 
-    fun openHomePage() {
-        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment::class.java))
+    fun openPostPageAndReplyTo(tweet: Tweet, prefix: String) {
+        val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+        postPage.setInReplyTo(tweet, prefix)
+        setSelectedPageIndex(pagerAdapter.getPageIndex(TAG_PAGE_POST), true)
+    }
+
+    fun openPostPageAndReplyTo(user: User) {
+        val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+        postPage.setInReplyTo(user)
+        setSelectedPageIndex(pagerAdapter.getPageIndex(TAG_PAGE_POST), true)
     }
 
-    fun openPostPage() {
-        setSelectedPageIndex(pagerAdapter.getIndex(PostFragment::class.java))
+    fun openPostPageAndAppendText(text: String) {
+        val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+        postPage.appendText(text)
+        setSelectedPageIndex(pagerAdapter.getPageIndex(TAG_PAGE_POST), true)
     }
 
     private fun openPostPageWithImage(uri: Uri) {
@@ -61,9 +77,8 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
             val c = contentResolver.query(uri, null, null, null, null)!!
             c.moveToFirst()
             val path = c.getString(c.getColumnIndex(MediaStore.MediaColumns.DATA))
-            world.postState.beginTransaction()
-                    .setMediaFilePath(path)
-                    .commitWithOpen(this)
+            val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+            postPage.setMediaFilePath(path)
             world.notify(R.string.notice_select_image_succeeded)
             c.close()
         } catch (e: Exception) {
@@ -74,23 +89,13 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
     }
 
     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))
-        }
+        val fragment = pagerAdapter.getPageFragment(TAG_PAGE_SEARCH) as SearchFragment
+        fragment.startSearch(query)
+        setSelectedPageIndex(pagerAdapter.getPageIndex(TAG_PAGE_SEARCH))
     }
 
     private fun setTitle() {
-        title = String.format("%s / %s", world.account.user.screenName, pagerAdapter.getName(viewPager.currentItem))
+        //title = String.format("%s / %s", world.account.user.screenName, pagerAdapter.getName(viewPager.currentItem))
         val label = getString(R.string.app_name) + " - @" + world.account.user.screenName
         if (android.os.Build.VERSION.SDK_INT >= 21) {
             setTaskDescription(ActivityManager.TaskDescription(label, null, world.account.themeColor))
@@ -168,7 +173,9 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
                     val via = uri.getQueryParameter("via")
                     if (!TextUtils.isEmpty(via))
                         text += " via @" + via
-                    world.postState.beginTransaction().setText(text).commitWithOpen(this)
+                    val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+                    postPage.setText(text)
+                    viewPager.setCurrentItem(pagerAdapter.getPageIndex(TAG_PAGE_POST), true)
                     return
                 }
                 val statusMatcher = TWITTER_STATUS_PATTERN.matcher(uri.path)
@@ -204,7 +211,9 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
                         if (!TextUtils.isEmpty(extra.getCharSequence(Intent.EXTRA_SUBJECT))) {
                             text = extra.getCharSequence(Intent.EXTRA_SUBJECT).toString() + " " + text
                         }
-                        world.postState.beginTransaction().setText(text).commitWithOpen(this)
+                        val postPage = pagerAdapter.getPageFragment(TAG_PAGE_POST) as PostFragment
+                        postPage.setText(text)
+                        viewPager.setCurrentItem(pagerAdapter.getPageIndex(TAG_PAGE_POST), true)
                         return
                     }
                 } else if (type != null && type.startsWith("image/")) {
@@ -217,16 +226,15 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
     // ------------------------ OVERRIDE METHODS ------------------------
 
     override fun onBackPressed() {
-        this.finish()
+        finish()
     }
 
     override fun finish() {
-        val homeIndex = pagerAdapter.getIndex(HomeFragment::class.java)
-        if (viewPager.currentItem != homeIndex) {
+        val homeIndex = pagerAdapter.getPageIndex(TAG_PAGE_HOME)
+        if (viewPager.currentItem != homeIndex)
             viewPager.setCurrentItem(homeIndex, true)
-        } else {
+        else
             confirm(R.string.dialog_confirm_finish_app) { super.finish() }
-        }
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
@@ -255,23 +263,31 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
         setContentView(R.layout.layout_main)
         setSupportActionBar(toolbar)
 
-        viewPager.addOnPageChangeListener(this)
-        //actionBar.setDisplayHomeAsUpEnabled(true)
-
-        // TODO: tab order?
         val args = Bundle()
         args.putLong(PageFragment.KEY_WORLD_USER_ID, account.id)
-        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 = MainFragmentPagerAdapter(fragmentManager, viewPager)
+        pagerAdapter.addPage(TAG_PAGE_POST, PostFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_HOME, HomeFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_MENTIONS, MentionsFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_EVENTS, HistoryFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_MESSAGES, MessagesFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_SEARCH, SearchFragment::class.java, args)
+        pagerAdapter.addPage(TAG_PAGE_LIST, UserListFragment::class.java, args)
         pagerAdapter.notifyDataSetChanged()
+
+        // TODO: tab order?
+        getString(R.string.page_name_post)
+        getString(R.string.page_name_home)
+        getString(R.string.page_name_mentions)
+        getString(R.string.page_name_history)
+        getString(R.string.page_name_messages)
+        getString(R.string.page_name_search)
+        getString(R.string.page_name_list)
+
+        viewPager.addOnPageChangeListener(this)
         viewPager.offscreenPageLimit = pagerAdapter.count
         viewPager.adapter = pagerAdapter
-        setSelectedPageIndex(pagerAdapter.getIndex(HomeFragment::class.java), false)
+        viewPager.setCurrentItem(pagerAdapter.getPageIndex(TAG_PAGE_HOME), false)
 
         ExtractionWord.load()
 
@@ -281,7 +297,7 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
         world.refreshSavedSearches()
 
         launchUi {
-            val user = try {
+            try {
                 world.getUserAsync(world.account.id)
             } catch (e: TwitterTaskException) {
                 return@launchUi
@@ -292,15 +308,6 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
         // Set application title
         setTitle()
 
-        // refresh all pages
-        for (i in 0 until pagerAdapter.count) {
-            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()
 
@@ -357,7 +364,8 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
 
     override fun onPageSelected(position: Int) {
         Logger.debug("Page selected: " + position)
-        setTitle()
+        //title = String.format("%s / %s", world.account.user.screenName, pagerAdapter.getName(viewPager.currentItem))
+        //setTitle()
     }
 
     override fun onPageScrollStateChanged(state: Int) {}
@@ -370,5 +378,12 @@ class MainActivity : AppCompatActivity(), ViewPager.OnPageChangeListener {
         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 TAG_PAGE_POST = "PAGE_POST"
+        private val TAG_PAGE_HOME = "PAGE_HOME"
+        private val TAG_PAGE_MENTIONS = "PAGE_MENTIONS"
+        private val TAG_PAGE_EVENTS = "PAGE_EVENTS"
+        private val TAG_PAGE_MESSAGES = "PAGE_MESSAGES"
+        private val TAG_PAGE_SEARCH = "PAGE_SEARCH"
+        private val TAG_PAGE_LIST = "PAGE_LIST"
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt b/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt
index 9565f4c0..4012891c 100644
--- a/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/command/CommandAddHashtag.kt
@@ -18,7 +18,7 @@ class CommandAddHashtag
     // -------------------------- OTHER METHODS --------------------------
 
     override fun execute(): Boolean {
-        activity.world.postState.beginTransaction().appendText(" #" + hashtag).commit()
+        activity.openPostPageAndAppendText(" #" + hashtag)
         return true
     }
 }
diff --git a/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt b/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt
deleted file mode 100644
index 74a09179..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/data/PostState.kt
+++ /dev/null
@@ -1,143 +0,0 @@
-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/view/MainFragmentPagerAdapter.kt b/app/src/main/java/net/lacolaco/smileessence/view/MainFragmentPagerAdapter.kt
new file mode 100644
index 00000000..add4c958
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/view/MainFragmentPagerAdapter.kt
@@ -0,0 +1,61 @@
+package net.lacolaco.smileessence.view
+
+import android.app.Fragment
+import android.app.FragmentManager
+import android.os.Bundle
+import android.support.v13.app.FragmentPagerAdapter
+import android.support.v4.util.ArrayMap
+import android.support.v4.view.ViewPager
+import android.view.ViewGroup
+import net.lacolaco.smileessence.view.page.PageFragment
+
+class MainFragmentPagerAdapter(fm: FragmentManager, private val viewPager: ViewPager) :
+        FragmentPagerAdapter(fm) {
+    private val pageTags = ArrayList<String>()
+    private val pages = ArrayMap<String, PageInfo>()
+
+    fun addPage(tag: String, clazz: Class<out PageFragment>, args: Bundle? = null) {
+        assert(pages[tag] == null)
+        pages[tag] = PageInfo(clazz, args)
+        pageTags.add(tag)
+    }
+
+    fun getPageFragment(tag: String): PageFragment {
+        // XXX: This is really an ugly workaround.
+        return pages[tag]!!.fragment ?: instantiateItem(viewPager, getPageIndex(tag)) as PageFragment
+    }
+
+    fun getPageIndex(tag: String): Int {
+        return pageTags.indexOf(tag)
+    }
+
+    override fun getItem(position: Int): Fragment {
+        val info = pages[pageTags[position]]!!
+        assert(info.fragment == null)
+        val fragment = info.clazz.newInstance()
+        if (info.args != null)
+            fragment.arguments = info.args
+        return fragment
+    }
+
+    override fun getCount(): Int {
+        return pages.size
+    }
+
+    override fun instantiateItem(container: ViewGroup, position: Int): Any {
+        val info = pages[pageTags[position]]!!
+        val fragment = super.instantiateItem(container, position)
+        info.fragment = fragment as PageFragment
+        return fragment
+    }
+
+    override fun destroyItem(container: ViewGroup?, position: Int, `object`: Any?) {
+        throw IllegalStateException("Fragments must not be destroyed by ViewPager")
+    }
+
+    private class PageInfo(
+            val clazz: Class<out PageFragment>,
+            val args: Bundle?,
+            var fragment: PageFragment? = null
+    )
+}
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
deleted file mode 100644
index 9589ffef..00000000
--- a/app/src/main/java/net/lacolaco/smileessence/view/adapter/PageListAdapter.kt
+++ /dev/null
@@ -1,140 +0,0 @@
-package net.lacolaco.smileessence.view.adapter
-
-import android.app.Fragment
-import android.app.FragmentManager
-import android.app.FragmentTransaction
-import android.os.Bundle
-import android.support.v4.view.PagerAdapter
-import android.view.View
-import android.view.ViewGroup
-import net.lacolaco.smileessence.BuildConfig
-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.*
-
-class PageListAdapter(_activity: MainActivity) : PagerAdapter() {
-    private val mFragmentManager: FragmentManager = _activity.fragmentManager
-    private var mCurTransaction: FragmentTransaction? = null
-    private var mCurrentPrimaryItem: Fragment? = null
-    private val pages = ArrayList<PageInfo>()
-    private val fragmentCache = HashMap<Int, WeakReference<PageFragment>>()
-
-    @Synchronized
-    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
-    }
-
-    fun addPage(klass: Class<out PageFragment>, name: String, args: Bundle, notifyChanged: Boolean) {
-        pages.add(PageInfo(klass, name, args))
-        if (notifyChanged) notifyDataSetChanged()
-    }
-
-    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)
-
-    override fun startUpdate(container: ViewGroup) {
-        assert(container.id != View.NO_ID)
-    }
-
-    override fun instantiateItem(container: ViewGroup, position: Int): Any {
-        if (mCurTransaction == null) {
-            mCurTransaction = mFragmentManager.beginTransaction()
-        }
-
-        val itemId = position.toLong()
-
-        // Do we already have this fragment?
-        val name = "android:switcher:${container.id}:$itemId"
-        var fragment: Fragment? = mFragmentManager.findFragmentByTag(name)
-        if (fragment != null) {
-            if (BuildConfig.DEBUG)
-                Logger.verbose("Attaching item #$itemId: f=$fragment")
-            mCurTransaction!!.attach(fragment)
-        } else {
-            fragment = getItem(position)
-            if (BuildConfig.DEBUG)
-                Logger.verbose("Adding item #$itemId: f=$fragment")
-            mCurTransaction!!.add(container.id, fragment, "android:switcher:${container.id}:$itemId")
-        }
-        if (fragment !== mCurrentPrimaryItem) {
-            fragment.setMenuVisibility(false)
-            fragment.userVisibleHint = false
-        }
-
-        return fragment
-    }
-
-    override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
-        if (mCurTransaction == null) {
-            mCurTransaction = mFragmentManager.beginTransaction()
-        }
-        if (BuildConfig.DEBUG)
-            Logger.verbose("Detaching item #" + position + ": f=" + `object`
-                    + " v=" + (`object` as Fragment).view)
-        mCurTransaction!!.detach(`object` as Fragment)
-    }
-
-    override fun setPrimaryItem(container: ViewGroup, position: Int, `object`: Any) {
-        val fragment = `object` as Fragment?
-        if (fragment !== mCurrentPrimaryItem) {
-            if (mCurrentPrimaryItem != null) {
-                mCurrentPrimaryItem!!.setMenuVisibility(false)
-                mCurrentPrimaryItem!!.userVisibleHint = false
-            }
-            if (fragment != null) {
-                fragment.setMenuVisibility(true)
-                fragment.userVisibleHint = true
-            }
-            mCurrentPrimaryItem = fragment
-        }
-    }
-
-    override fun finishUpdate(container: ViewGroup) {
-        if (mCurTransaction != null) {
-            mCurTransaction!!.commitAllowingStateLoss()
-            mCurTransaction = null
-            mFragmentManager.executePendingTransactions()
-        }
-    }
-
-    override fun isViewFromObject(view: View, `object`: Any): Boolean {
-        return (`object` as Fragment).view === view
-    }
-}
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
index 97134ce4..78c67ce6 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/StatusDetailDialogFragment.kt
@@ -6,7 +6,6 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import kotlinx.android.synthetic.main.dialog_status_detail.view.*
-import kotlinx.android.synthetic.main.menu_item_simple_text.view.*
 import net.lacolaco.smileessence.R
 import net.lacolaco.smileessence.activity.MainActivity
 import net.lacolaco.smileessence.command.Command
@@ -109,12 +108,7 @@ class StatusDetailDialogFragment : StackableDialogFragment() {
             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)
+            (activity as MainActivity).openPostPageAndReplyTo(originalTweet, text)
         }
         view.button_status_detail_retweet.setOnClickListener {
             val account = world.account
@@ -181,7 +175,7 @@ class StatusDetailDialogFragment : StackableDialogFragment() {
             val popup = PopupMenu(activity, view.button_status_detail_menu)
             popup.add(R.string.command_status_add_to_reply) {
                 val text = String.format("@%s ", tweet.originalTweet.user.screenName)
-                world.postState.beginTransaction().insertText(0, text).moveCursor(text.length).commit()
+                (activity as MainActivity).openPostPageAndAppendText(text)
                 world.notify(R.string.notice_add_to_reply)
             }
             popup.add(R.string.command_status_open_talk_view) {
@@ -222,7 +216,7 @@ class StatusDetailDialogFragment : StackableDialogFragment() {
             val adapter = object : UnorderedCustomListAdapter<Command>(commands) {
                 override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
                     val itemView = convertView ?: activity.layoutInflater.inflate(R.layout.menu_item_simple_text, parent, false)
-                    itemView.list_item_textview.text = getItem(position).text
+                    TODO("not implemented") //To change body of created functions use File | Settings | File Templates.itemView.list_item_textview.text = getItem(position).text
                     return itemView
                 }
             }
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
index e68a38a1..d4bea45f 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/view/dialog/UserDetailDialogFragment.kt
@@ -11,6 +11,7 @@ import com.omadahealth.github.swipyrefreshlayout.library.SwipyRefreshLayoutDirec
 import kotlinx.android.synthetic.main.dialog_user_detail.*
 import kotlinx.android.synthetic.main.dialog_user_detail.view.*
 import net.lacolaco.smileessence.R
+import net.lacolaco.smileessence.activity.MainActivity
 import net.lacolaco.smileessence.data.ImageCache
 import net.lacolaco.smileessence.entity.User
 import net.lacolaco.smileessence.twitter.TwitterTaskException
@@ -30,8 +31,7 @@ class UserDetailDialogFragment : StackableDialogFragment() {
     private fun showPopupMenu() {
         val popup = PopupMenu(activity, imageview_user_detail_menu)
         popup.add(R.string.command_user_add_to_reply) {
-            val text = String.format("@%s ", user.screenName)
-            world.postState.beginTransaction().insertText(0, text).moveCursor(text.length).commit()
+            (activity as MainActivity).openPostPageAndReplyTo(user)
             world.notify(R.string.notice_add_to_reply)
         }
         popup.add(R.string.command_user_send_message) {
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
index 81db9412..f23a9edf 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/PageFragment.kt
@@ -3,6 +3,9 @@ package net.lacolaco.smileessence.view.page
 import android.app.Fragment
 import net.lacolaco.smileessence.Application
 
+/**
+ * A PageFragment is always attached to a MainActivity.
+ */
 abstract class PageFragment : Fragment() {
     protected val world by lazy {
         Application.getWorld(arguments.getLong(KEY_WORLD_USER_ID))
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
index 044261f4..93cb670f 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/PostFragment.kt
@@ -1,8 +1,10 @@
 package net.lacolaco.smileessence.view.page
 
+import android.annotation.SuppressLint
 import android.content.Intent
 import android.net.Uri
 import android.os.Bundle
+import android.os.Parcelable
 import android.support.v4.content.ContextCompat
 import android.text.Editable
 import android.text.Spannable
@@ -12,12 +14,13 @@ import android.text.method.ArrowKeyMovementMethod
 import android.view.*
 import android.widget.TextView
 import com.twitter.Validator
+import kotlinx.android.parcel.Parcelize
 import kotlinx.android.synthetic.main.fragment_post.*
 import net.lacolaco.smileessence.R
 import net.lacolaco.smileessence.activity.MainActivity
-import net.lacolaco.smileessence.data.PostState
+import net.lacolaco.smileessence.entity.Tweet
+import net.lacolaco.smileessence.entity.User
 import net.lacolaco.smileessence.logging.Logger
-import net.lacolaco.smileessence.preference.UserPreferenceHelper
 import net.lacolaco.smileessence.twitter.TwitterTaskException
 import net.lacolaco.smileessence.twitter.task.createTweetAsync
 import net.lacolaco.smileessence.util.BitmapThumbnailTask
@@ -25,28 +28,60 @@ import net.lacolaco.smileessence.util.SystemServiceHelper
 import net.lacolaco.smileessence.util.UIHandler
 import net.lacolaco.smileessence.util.launchUi
 import net.lacolaco.smileessence.view.Partials
+import twitter4j.StatusUpdate
 import java.io.File
 
-class PostFragment : PageFragment(), TextWatcher, PostState.OnPostStateChangeListener {
+class PostFragment : PageFragment(), TextWatcher {
+    private lateinit var postState: PostState
+
     override fun refresh() {}
 
-    override fun onPostStateChange(postState: PostState) {
+    fun setMediaFilePath(path: String) {
+        postState.mediaFilePath = path
+        onPostStateChange()
+    }
+
+    fun setInReplyTo(tweet: Tweet, prefix: String) {
+        postState.inReplyTo = tweet
+        postState.text = prefix + postState.text
+        postState.selectionStart = prefix.length
+        postState.selectionEnd = prefix.length
+        onPostStateChange()
+    }
+
+    fun setInReplyTo(user: User) {
+        val prefix = "@${user.screenName} "
+        postState.text = prefix + postState.text
+        postState.selectionStart += prefix.length
+        postState.selectionEnd += prefix.length
+        onPostStateChange()
+    }
+
+    fun setText(text: String) {
+        postState.text = text
+        onPostStateChange()
+    }
+
+    fun appendText(text: String) {
+        postState.text += text
+        onPostStateChange()
+    }
+
+    private fun onPostStateChange() {
         Logger.debug("onPostStateChange")
-        val activity = activity as MainActivity
-        val start = postState.selectionStart
-        val end = postState.selectionEnd
         post_edit_text.removeTextChangedListener(this)
         post_edit_text.setTextKeepState(postState.text)
         post_edit_text.addTextChangedListener(this)
         updateTextCount(post_edit_text.text)
-        UIHandler().postAtFrontOfQueue { post_edit_text.setSelection(start, end) }
+        UIHandler().postAtFrontOfQueue {
+            post_edit_text.setSelection(postState.selectionStart, postState.selectionEnd)
+        }
 
         if (postState.inReplyTo != null) {
             post_inreplyto_parent.visibility = View.VISIBLE
-
-            val tweet = postState.inReplyTo
-            val header = Partials.getTweetView(tweet!!, world, activity, layout_post_reply_status)
-            header.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.transparent))
+            val header = Partials.getTweetView(postState.inReplyTo!!, world, activity,
+                    layout_post_reply_status)
+            header.setBackgroundColor(ContextCompat.getColor(activity, R.color.transparent))
             header.isClickable = false
         } else {
             post_inreplyto_parent.visibility = View.GONE
@@ -60,18 +95,19 @@ class PostFragment : PageFragment(), TextWatcher, PostState.OnPostStateChangeLis
         BitmapThumbnailTask(postState.mediaFilePath, image_post_media).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)
+        postState.text = s.toString()
     }
 
+    override fun afterTextChanged(s: Editable) {}
+
     private fun updateTextCount(s: CharSequence) {
         val validator = Validator()
         var length = validator.getTweetLength(s.toString())
-        if (!TextUtils.isEmpty(world.postState.mediaFilePath))
+        if (!TextUtils.isEmpty(postState.mediaFilePath))
             length += validator.shortUrlLength
 
         post_text_count.text = length.toString()
@@ -81,12 +117,20 @@ class PostFragment : PageFragment(), TextWatcher, PostState.OnPostStateChangeLis
         } else {
             post_text_count.setTextAppearance(activity, android.R.style.TextAppearance_Widget_TextView)
         }
-        setStateFromView()
     }
 
-    override fun afterTextChanged(s: Editable) {}
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        if (savedInstanceState != null)
+            postState = savedInstanceState.getParcelable(KEY_POST_STATE)
+        else
+            postState = PostState()
+    }
 
-    // ------------------------ OVERRIDE METHODS ------------------------
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        outState.putParcelable(KEY_POST_STATE, postState)
+    }
 
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
         super.onCreateOptionsMenu(menu, inflater)
@@ -94,14 +138,11 @@ class PostFragment : PageFragment(), TextWatcher, PostState.OnPostStateChangeLis
     }
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-        setHasOptionsMenu(true)
         return inflater.inflate(R.layout.fragment_post, container, false)
     }
 
     override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
-        world.postState.setListener(this)
-        button_post_tweet.setOnClickListener { submitPost() }
         post_edit_text.addTextChangedListener(this)
         post_edit_text.setOnFocusChangeListener { _, hasFocus ->
             if (hasFocus)
@@ -111,92 +152,84 @@ class PostFragment : PageFragment(), TextWatcher, PostState.OnPostStateChangeLis
         }
         post_edit_text.movementMethod = object : ArrowKeyMovementMethod() {
             override fun right(widget: TextView, buffer: Spannable): Boolean {
-                //Don't back to Home
+                // Don't back to Home
                 return widget.selectionEnd == widget.length() || super.right(widget, buffer)
             }
         }
-        button_post_delete.setOnClickListener { deletePost() }
-        button_post_media.setOnClickListener { setImage() }
-        //Reply view
-        button_post_reply_delete.setOnClickListener { deleteReply() }
-        //Media view
-        image_post_media.setOnClickListener { displayImage() }
-        button_post_media_delete.setOnClickListener { removeImage() }
-    }
-
-    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() {
-        post_edit_text.setText("")
-        world.postState.beginTransaction().setText("").setCursor(0).commit()
-        deleteReply()
-    }
-
-    private fun deleteReply() {
-        post_inreplyto_parent.visibility = View.GONE
-        world.postState.beginTransaction().setInReplyTo(null).commit()
-    }
-
-    private fun displayImage() {
-        val intent = Intent(Intent.ACTION_VIEW)
-        intent.addCategory(Intent.CATEGORY_DEFAULT)
-        intent.setDataAndType(Uri.fromFile(File(world.postState.mediaFilePath)), "image/*")
-        startActivity(intent)
-    }
+        button_post_tweet.setOnClickListener {
+            SystemServiceHelper.hideIM(activity, post_edit_text)
+            launchUi {
+                try {
+                    val su = StatusUpdate(postState.text)
+                    if (postState.inReplyTo != null) {
+                        su.inReplyToStatusId = postState.inReplyTo!!.id
+                    }
+                    world.createTweetAsync(su, postState.mediaFilePath, false).await()
+                    world.notify(R.string.notice_tweet_succeeded)
+                    postState.clear()
+                } catch (e: TwitterTaskException) {
+                    world.notifyError(R.string.notice_tweet_failed, e)
+                }
+            }
+            (activity as MainActivity).openHomePage()
+        }
+        button_post_reply_delete.setOnClickListener {
+            postState.inReplyTo = null
+            onPostStateChange()
+        }
+        button_post_delete.setOnClickListener {
+            postState.clear()
+            onPostStateChange()
+        }
+        button_post_media.setOnClickListener {
+            SystemServiceHelper.hideIM(activity, post_edit_text)
 
-    private fun removeImage() {
-        SystemServiceHelper.hideIM(activity, post_edit_text)
-        post_media_parent.visibility = View.GONE
-        image_post_media.setImageBitmap(null)
-        world.postState.beginTransaction().setMediaFilePath("").commit()
+            val intent = Intent(Intent.ACTION_PICK)
+            intent.type = "image/*"
+            startActivityForResult(intent, MainActivity.REQUEST_GET_PICTURE_FROM_GALLERY)
+        }
+        image_post_media.setOnClickListener {
+            val intent = Intent(Intent.ACTION_VIEW)
+            intent.addCategory(Intent.CATEGORY_DEFAULT)
+            intent.setDataAndType(Uri.fromFile(File(postState.mediaFilePath)), "image/*")
+            startActivity(intent)
+        }
+        button_post_media_delete.setOnClickListener {
+            SystemServiceHelper.hideIM(activity, post_edit_text)
+            post_media_parent.visibility = View.GONE
+            image_post_media.setImageBitmap(null)
+            postState.mediaFilePath = ""
+            onPostStateChange()
+        }
+        onPostStateChange()
     }
 
-    private fun setImage() {
-        setStateFromView()
-        SystemServiceHelper.hideIM(activity, post_edit_text)
-
-        val intent = Intent(Intent.ACTION_PICK)
-        intent.type = "image/*"
-        startActivityForResult(intent, MainActivity.REQUEST_GET_PICTURE_FROM_GALLERY)
-    }
+    // FIXME: Remove @SuppressList
+    @SuppressLint("ParcelCreator")
+    @Parcelize
+    private class PostState(
+            var text: String = "",
+            private var inReplyToId: Long = -1,
+            var mediaFilePath: String = "",
+            var selectionStart: Int = 0,
+            var selectionEnd: Int = 0
+    ) : Parcelable {
+        var inReplyTo: Tweet?
+            get() = if (inReplyToId != -1L) Tweet.fetch(inReplyToId) else null
+            set(value) {
+                inReplyToId = value?.id ?: -1
+            }
 
-    private fun setStateFromView() {
-        val state = world.postState
-        state.removeListener()
-        state.beginTransaction()
-                .setText(post_edit_text.text.toString())
-                .setSelection(post_edit_text.selectionStart, post_edit_text.selectionEnd)
-                .commit()
-        state.setListener(this)
+        fun clear() {
+            text = ""
+            inReplyTo = null
+            mediaFilePath = ""
+            selectionStart = 0
+            selectionEnd = 0
+        }
     }
 
-    private fun submitPost() {
-        SystemServiceHelper.hideIM(activity, post_edit_text)
-        setStateFromView()
-        launchUi {
-            val state = world.postState
-            val resizeFlag = UserPreferenceHelper.instance[R.string.key_setting_resize_post_image, false]
-            try {
-                val t = world.createTweetAsync(state.toStatusUpdate(), state.mediaFilePath, resizeFlag).await()
-                world.notify(R.string.notice_tweet_succeeded)
-                world.postState.beginTransaction().clear().commit()
-            } catch (e: TwitterTaskException) {
-                world.notifyError(R.string.notice_tweet_failed, e)
-            }
-        }
-        val mainActivity = activity as MainActivity
-        mainActivity.openHomePage()
+    companion object {
+        val KEY_POST_STATE = "POST_STATE"
     }
 }
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
index 2bedf71d..55193aea 100644
--- a/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.kt
+++ b/app/src/main/java/net/lacolaco/smileessence/view/page/UserListFragment.kt
@@ -9,7 +9,6 @@ import com.omadahealth.github.swipyrefreshlayout.library.SwipyRefreshLayout
 import kotlinx.android.synthetic.main.fragment_userlist.*
 import kotlinx.coroutines.experimental.Deferred
 import net.lacolaco.smileessence.R
-import net.lacolaco.smileessence.activity.MainActivity
 import net.lacolaco.smileessence.entity.Tweet
 import net.lacolaco.smileessence.preference.UserPreferenceHelper
 import net.lacolaco.smileessence.twitter.TwitterTaskException
@@ -75,7 +74,7 @@ class UserListFragment : CustomListFragment<TimelineAdapter>() {
             for (name in world.listSubscriptions) {
                 popup.add(name) {
                     textview_userlist_name.text = name
-                    (activity as MainActivity).openUserListPage(name)
+                    startUserList(name)
                 }
             }
             popup.show()