Library views recycling

app/src/main/java/eu/kanade/tachiyomi/widget/RecyclerViewPagerAdapter.kt

@@ -0,0 +1,42 @@
+package eu.kanade.tachiyomi.widget
+
+import android.support.v4.view.PagerAdapter
+import android.view.View
+import android.view.ViewGroup
+import java.util.*
+
+abstract class RecyclerViewPagerAdapter : PagerAdapter() {
+
+    private val pool = Stack<View>()
+
+    var recycle = true
+        set(value) {
+            if (!value) pool.clear()
+            field = value
+        }
+
+    protected abstract fun createView(container: ViewGroup): View
+
+    protected abstract fun bindView(view: View, position: Int)
+
+    protected open fun recycleView(view: View, position: Int) {}
+
+    override fun instantiateItem(container: ViewGroup, position: Int): Any {
+        val view = if (pool.isNotEmpty()) pool.pop() else createView(container)
+        bindView(view, position)
+        container.addView(view)
+        return view
+    }
+
+    override fun destroyItem(container: ViewGroup, position: Int, obj: Any) {
+        val view = obj as View
+        recycleView(view, position)
+        container.removeView(view)
+        if (recycle) pool.push(view)
+    }
+
+    override fun isViewFromObject(view: View, obj: Any): Boolean {
+        return view === obj
+    }
+
+}