Add RecyclerViewCompositionStrategy.DisposeOnRecycled for re-using mo…

…re compositions in RecyclerView

dpadrecyclerview-compose/api/dpadrecyclerview-compose.api

@@ -19,3 +19,14 @@ public class com/rubensousa/dpadrecyclerview/compose/DpadComposeViewHolder : com
 	public fun Content (Ljava/lang/Object;ZZLandroidx/compose/runtime/Composer;I)V
 }
 
+public final class com/rubensousa/dpadrecyclerview/compose/RecyclerViewCompositionStrategy {
+	public static final field $stable I
+	public static final field INSTANCE Lcom/rubensousa/dpadrecyclerview/compose/RecyclerViewCompositionStrategy;
+}
+
+public final class com/rubensousa/dpadrecyclerview/compose/RecyclerViewCompositionStrategy$DisposeOnRecycled : androidx/compose/ui/platform/ViewCompositionStrategy {
+	public static final field $stable I
+	public static final field INSTANCE Lcom/rubensousa/dpadrecyclerview/compose/RecyclerViewCompositionStrategy$DisposeOnRecycled;
+	public fun installFor (Landroidx/compose/ui/platform/AbstractComposeView;)Lkotlin/jvm/functions/Function0;
+}
+

dpadrecyclerview-compose/src/androidTest/java/com/rubensousa/dpadrecyclerview/compose/DpadComposeViewHolderTest.kt

@@ -20,6 +20,7 @@ import androidx.compose.ui.platform.ComposeView
 import androidx.compose.ui.test.SemanticsMatcher
 import androidx.compose.ui.test.assert
 import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.assertIsNotDisplayed
 import androidx.compose.ui.test.junit4.createAndroidComposeRule
 import androidx.compose.ui.test.onNodeWithText
 import androidx.recyclerview.widget.RecyclerView
@@ -28,6 +29,7 @@ import androidx.test.espresso.Espresso.onView
 import androidx.test.espresso.matcher.ViewMatchers
 import com.google.common.truth.Truth.assertThat
 import com.rubensousa.dpadrecyclerview.DpadRecyclerView
+import com.rubensousa.dpadrecyclerview.ExtraLayoutSpaceStrategy
 import com.rubensousa.dpadrecyclerview.testing.KeyEvents
 import com.rubensousa.dpadrecyclerview.testing.actions.DpadRecyclerViewActions
 import org.junit.Rule
@@ -48,6 +50,15 @@ class DpadComposeViewHolderTest {
 
         assertFocus(item = 2, isFocused = false)
         assertSelection(item = 2, isSelected = false)
+
+        KeyEvents.pressDown()
+        waitForIdleScroll()
+
+        assertFocus(item = 0, isFocused = false)
+        assertSelection(item = 0, isSelected = false)
+
+        assertFocus(item = 1, isFocused = true)
+        assertSelection(item = 1, isSelected = true)
     }
 
     @Test
@@ -107,7 +118,7 @@ class DpadComposeViewHolderTest {
     }
 
     @Test
-    fun testCompositionIsCleared() {
+    fun testCompositionIsClearedWhenClearingAdapter() {
         val viewHolders = ArrayList<RecyclerView.ViewHolder>()
         composeTestRule.activityRule.scenario.onActivity { activity ->
             viewHolders.addAll(activity.getViewsHolders())
@@ -121,6 +132,41 @@ class DpadComposeViewHolderTest {
         composeTestRule.onNodeWithText("0").assertDoesNotExist()
     }
 
+    @Test
+    fun testCompositionIsNotClearedWhenDetachingFromWindow() {
+        composeTestRule.activityRule.scenario.onActivity { activity ->
+            activity.getRecyclerView().setExtraLayoutSpaceStrategy(object : ExtraLayoutSpaceStrategy {
+                override fun calculateStartExtraLayoutSpace(state: RecyclerView.State): Int {
+                    return 1080
+                }
+            })
+        }
+        repeat(3) {
+            KeyEvents.pressDown()
+            waitForIdleScroll()
+        }
+
+        composeTestRule.onNodeWithText("0").assertExists()
+        composeTestRule.onNodeWithText("0").assertIsNotDisplayed()
+    }
+
+    @Test
+    fun testCompositionIsClearedWhenViewHolderIsRecycled() {
+        repeat(5) {
+            KeyEvents.pressDown()
+            waitForIdleScroll()
+        }
+
+        composeTestRule.onNodeWithText("0").assertDoesNotExist()
+
+        var disposals: List<Int> = emptyList()
+        composeTestRule.activityRule.scenario.onActivity { activity ->
+            disposals = activity.getDisposals()
+        }
+
+        assertThat(disposals).contains(0)
+    }
+
     private fun waitForIdleScroll() {
         onView(ViewMatchers.isAssignableFrom(DpadRecyclerView::class.java))
             .perform(DpadRecyclerViewActions.waitForIdleScroll())

dpadrecyclerview-compose/src/debug/java/com/rubensousa/dpadrecyclerview/compose/TestActivity.kt

@@ -32,12 +32,18 @@ class TestActivity : AppCompatActivity() {
 
     private lateinit var recyclerView: DpadRecyclerView
     private val clicks = ArrayList<Int>()
+    private val disposals = ArrayList<Int>()
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.compose_test)
         recyclerView = findViewById(R.id.recyclerView)
-        recyclerView.adapter = Adapter(List(100) { it })
+        recyclerView.adapter = Adapter(
+            items = List(100) { it },
+            onDispose = { item ->
+                disposals.add(item)
+            }
+        )
         recyclerView.requestFocus()
     }
 
@@ -53,10 +59,16 @@ class TestActivity : AppCompatActivity() {
         return clicks
     }
 
+    fun getDisposals(): List<Int> {
+        return disposals
+    }
+
     fun removeAdapter() {
         recyclerView.adapter = null
     }
 
+    fun getRecyclerView(): DpadRecyclerView = recyclerView
+
     fun getViewsHolders(): List<RecyclerView.ViewHolder> {
         val viewHolders = ArrayList<RecyclerView.ViewHolder>()
         recyclerView.children.forEach { child ->
@@ -65,28 +77,35 @@ class TestActivity : AppCompatActivity() {
         return viewHolders
     }
 
-    inner class Adapter(private val items: List<Int>) :
-        RecyclerView.Adapter<DpadComposeViewHolder<Int>>() {
+    inner class Adapter(
+        private val items: List<Int>,
+        private val onDispose: (item: Int) -> Unit,
+    ) : RecyclerView.Adapter<DpadComposeViewHolder<Int>>() {
 
         override fun onCreateViewHolder(
             parent: ViewGroup,
             viewType: Int
         ): DpadComposeViewHolder<Int> {
-            return DpadComposeViewHolder(parent,
+            return DpadComposeViewHolder(
+                parent,
                 composable = { item, isFocused, isSelected ->
                     TestComposable(
                         modifier = Modifier
                             .fillMaxWidth()
                             .height(150.dp),
                         item = item,
                         isFocused = isFocused,
-                        isSelected = isSelected
+                        isSelected = isSelected,
+                        onDispose = {
+                            onDispose(item)
+                        }
                     )
                 },
                 onClick = {
                     clicks.add(it)
                 },
-                isFocusable = true)
+                isFocusable = true
+            )
         }
 
         override fun getItemCount(): Int = items.size

dpadrecyclerview-compose/src/debug/java/com/rubensousa/dpadrecyclerview/compose/TestComposable.kt

@@ -18,8 +18,10 @@ package com.rubensousa.dpadrecyclerview.compose
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -37,7 +39,8 @@ fun TestComposable(
     modifier: Modifier = Modifier,
     item: Int,
     isFocused: Boolean,
-    isSelected: Boolean
+    isSelected: Boolean,
+    onDispose: () -> Unit = {},
 ) {
     val backgroundColor = if (isFocused) {
         Color.White
@@ -51,10 +54,24 @@ fun TestComposable(
             .background(backgroundColor),
         contentAlignment = Alignment.Center,
     ) {
-        Text(modifier = Modifier.semantics {
-            set(TestComposable.focusedKey, isFocused)
-            set(TestComposable.selectedKey, isSelected)
-        }, text = item.toString())
+        Text(
+            modifier = Modifier.semantics {
+                set(TestComposable.focusedKey, isFocused)
+                set(TestComposable.selectedKey, isSelected)
+            },
+            text = item.toString(),
+            style = MaterialTheme.typography.headlineLarge,
+            color = if(isFocused) {
+                Color.Black
+            } else {
+                Color.White
+            }
+        )
+    }
+    DisposableEffect(key1 = item) {
+        onDispose {
+            onDispose()
+        }
     }
 }
 

dpadrecyclerview-compose/src/main/java/com/rubensousa/dpadrecyclerview/compose/DpadAbstractComposeViewHolder.kt

@@ -50,6 +50,7 @@ abstract class DpadAbstractComposeViewHolder<T>(
 
     init {
         val composeView = itemView as ComposeView
+        composeView.setViewCompositionStrategy(RecyclerViewCompositionStrategy.DisposeOnRecycled)
         composeView.isFocusable = isFocusable
         composeView.isFocusableInTouchMode = isFocusable
         composeView.descendantFocusability = ViewGroup.FOCUS_BLOCK_DESCENDANTS

dpadrecyclerview-compose/src/main/java/com/rubensousa/dpadrecyclerview/compose/RecyclerViewCompositionStrategy.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2024 Rúben Sousa
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.rubensousa.dpadrecyclerview.compose
+
+import androidx.compose.ui.platform.AbstractComposeView
+import androidx.compose.ui.platform.ViewCompositionStrategy
+import androidx.customview.poolingcontainer.PoolingContainerListener
+import androidx.customview.poolingcontainer.addPoolingContainerListener
+import androidx.customview.poolingcontainer.removePoolingContainerListener
+import com.rubensousa.dpadrecyclerview.DpadRecyclerView
+
+object RecyclerViewCompositionStrategy {
+
+    /**
+     * Similar to [ViewCompositionStrategy.DisposeOnDetachedFromWindowOrReleasedFromPool] but skips
+     * releasing compositions when detached from window. This is useful for re-using compositions
+     * a lot more often when scrolling a RecyclerView.
+     *
+     * If you use [DpadRecyclerView.setRecycleChildrenOnDetach],
+     * this will behave exactly the same as [ViewCompositionStrategy.DisposeOnDetachedFromWindowOrReleasedFromPool].
+     *
+     * If you use [DpadRecyclerView.setExtraLayoutSpaceStrategy],
+     * please profile the compositions before considering using this strategy.
+     */
+    object DisposeOnRecycled : ViewCompositionStrategy {
+        override fun installFor(view: AbstractComposeView): () -> Unit {
+            val poolingContainerListener = PoolingContainerListener {
+                view.disposeComposition()
+            }
+            view.addPoolingContainerListener(poolingContainerListener)
+            return {
+                view.removePoolingContainerListener(poolingContainerListener)
+            }
+        }
+    }
+
+}