1 files changed, 41 insertions, 0 deletions
diff --git a/app/src/main/java/net/lacolaco/smileessence/util/SortedList.kt b/app/src/main/java/net/lacolaco/smileessence/util/SortedList.kt
new file mode 100644
index 00000000..b0c0e205
--- /dev/null
+++ b/app/src/main/java/net/lacolaco/smileessence/util/SortedList.kt
@@ -0,0 +1,41 @@
+package net.lacolaco.smileessence.util
+
+import net.lacolaco.smileessence.entity.IdObject
+import java.util.*
+
+class SortedList<T : IdObject> constructor(
+        private val onInserted: (Int) -> Unit,
+        private val onRemoved: (Int, Int) -> Unit,
+        initialCapacity: Int = 32
+) {
+    private var arrayList = ArrayList<T>(initialCapacity)
+
+    fun add(item: T): Int {
+        val pos = arrayList.binarySearchBy(item.id, selector = { it.id })
+        if (pos >= 0)
+            return applyReversedOrder(pos)
+        arrayList.add(-pos - 1, item)
+        onInserted(applyReversedOrder(-pos - 1))
+        return applyReversedOrder(-pos - 1)
+    }
+
+    fun addAll(items: Collection<T>) {
+        items.forEach { add(it) }
+    }
+
+    operator fun get(index: Int): T {
+        return arrayList[applyReversedOrder(index)]
+    }
+
+    fun clear() {
+        val size = arrayList.size
+        arrayList.clear()
+        onRemoved(0, size)
+    }
+
+    val size
+        get() = arrayList.size
+
+    private fun applyReversedOrder(pos: Int): Int
+            = arrayList.size - pos - 1
+}