Revert "Revert AllAppsRecyclerViewPoolTest.kt"

This reverts commit 6554ab99e34230c3e386f3a91b82151b10a07bc4.

Reason for revert: Since ag/28600866 was the real fix of b/354560500, we should restore the AllAppsRecyclerViewPoolTest.kt

Fix: 359247985
Test: Presubmit
Flag: NONE - released

Change-Id: I54c3a4d15ec5a9e96cd03c465d10898ef6ac2078
diff --git a/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPool.kt b/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPool.kt
index 82229f8..e4c50f0 100644
--- a/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPool.kt
+++ b/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPool.kt
@@ -18,18 +18,23 @@
 
 import android.content.Context
 import android.util.Log
+import android.view.InflateException
+import androidx.annotation.VisibleForTesting
+import androidx.annotation.VisibleForTesting.Companion.PROTECTED
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.RecycledViewPool
 import androidx.recyclerview.widget.RecyclerView.ViewHolder
 import com.android.launcher3.BubbleTextView
 import com.android.launcher3.BuildConfig
 import com.android.launcher3.allapps.BaseAllAppsAdapter
+import com.android.launcher3.config.FeatureFlags
 import com.android.launcher3.util.CancellableTask
 import com.android.launcher3.util.Executors.MAIN_EXECUTOR
 import com.android.launcher3.util.Executors.VIEW_PREINFLATION_EXECUTOR
 import com.android.launcher3.util.Themes
 import com.android.launcher3.views.ActivityContext
 import com.android.launcher3.views.ActivityContext.ActivityContextDelegate
+import java.lang.IllegalStateException
 
 const val PREINFLATE_ICONS_ROW_COUNT = 4
 const val EXTRA_ICONS_COUNT = 2
@@ -39,10 +44,11 @@
  * [RecyclerView]. The view inflation will happen on background thread and inflated [ViewHolder]s
  * will be added to [RecycledViewPool] on main thread.
  */
-class AllAppsRecyclerViewPool<T> : RecycledViewPool() {
+class AllAppsRecyclerViewPool<T> : RecycledViewPool() where T : Context, T : ActivityContext {
 
     var hasWorkProfile = false
-    private var mCancellableTask: CancellableTask<List<ViewHolder>>? = null
+    @VisibleForTesting(otherwise = PROTECTED)
+    var mCancellableTask: CancellableTask<List<ViewHolder>>? = null
 
     companion object {
         private const val TAG = "AllAppsRecyclerViewPool"
@@ -53,7 +59,7 @@
     /**
      * Preinflate app icons. If all apps RV cannot be scrolled down, we don't need to preinflate.
      */
-    fun <T> preInflateAllAppsViewHolders(context: T) where T : Context, T : ActivityContext {
+    fun preInflateAllAppsViewHolders(context: T) {
         val appsView = context.appsView ?: return
         val activeRv: RecyclerView = appsView.activeRecyclerView ?: return
         val preInflateCount = getPreinflateCount(context)
@@ -97,36 +103,65 @@
                 override fun getLayoutManager(): RecyclerView.LayoutManager? = null
             }
 
+        preInflateAllAppsViewHolders(
+            adapter,
+            BaseAllAppsAdapter.VIEW_TYPE_ICON,
+            activeRv,
+            preInflateCount,
+        ) {
+            getPreinflateCount(context)
+        }
+    }
+
+    @VisibleForTesting(otherwise = PROTECTED)
+    fun preInflateAllAppsViewHolders(
+        adapter: RecyclerView.Adapter<*>,
+        viewType: Int,
+        activeRv: RecyclerView,
+        preInflationCount: Int,
+        preInflationCountProvider: () -> Int,
+    ) {
+        if (preInflationCount <= 0) {
+            return
+        }
         mCancellableTask?.cancel()
         var task: CancellableTask<List<ViewHolder>>? = null
         task =
             CancellableTask(
                 {
                     val list: ArrayList<ViewHolder> = ArrayList()
-                    for (i in 0 until preInflateCount) {
+                    for (i in 0 until preInflationCount) {
                         if (task?.canceled == true) {
                             break
                         }
                         // If activeRv's layout manager has been reset to null on main thread, skip
                         // the preinflation as we cannot generate correct LayoutParams
                         if (activeRv.layoutManager == null) {
+                            list.clear()
                             break
                         }
-                        list.add(
-                            adapter.createViewHolder(activeRv, BaseAllAppsAdapter.VIEW_TYPE_ICON)
-                        )
+                        try {
+                            list.add(adapter.createViewHolder(activeRv, viewType))
+                        } catch (e: InflateException) {
+                            list.clear()
+                            // It's still possible for UI thread to set activeRv's layout manager to
+                            // null and we should break the loop and cancel the preinflation.
+                            break
+                        }
                     }
                     list
                 },
                 MAIN_EXECUTOR,
                 { viewHolders ->
-                    for (i in 0 until minOf(viewHolders.size, getPreinflateCount(context))) {
+                    // Run preInflationCountProvider again as the needed VH might have changed
+                    val newPreInflationCount = preInflationCountProvider.invoke()
+                    for (i in 0 until minOf(viewHolders.size, newPreInflationCount)) {
                         putRecycledView(viewHolders[i])
                     }
                 },
             )
         mCancellableTask = task
-        VIEW_PREINFLATION_EXECUTOR.submit(mCancellableTask)
+        VIEW_PREINFLATION_EXECUTOR.execute(mCancellableTask)
     }
 
     /**
@@ -143,10 +178,11 @@
      * app icons plus [EXTRA_ICONS_COUNT] is the magic minimal count of app icons to preinflate to
      * suffice fast scrolling.
      *
-     * Note that we need to preinfate extra app icons in size of one all apps pages, so that opening
-     * all apps don't need to inflate app icons.
+     * Note that if [FeatureFlags.ALL_APPS_GONE_VISIBILITY] is enabled, we need to preinfate extra
+     * app icons in size of one all apps pages, so that opening all apps don't need to inflate app
+     * icons.
      */
-    fun <T> getPreinflateCount(context: T): Int where T : Context, T : ActivityContext {
+    fun getPreinflateCount(context: T): Int {
         var targetPreinflateCount =
             PREINFLATE_ICONS_ROW_COUNT * context.deviceProfile.numShownAllAppsColumns +
                 EXTRA_ICONS_COUNT
diff --git a/tests/multivalentTests/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPoolTest.kt b/tests/multivalentTests/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPoolTest.kt
new file mode 100644
index 0000000..3afb0b5
--- /dev/null
+++ b/tests/multivalentTests/src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPoolTest.kt
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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.android.launcher3.recyclerview
+
+import android.content.Context
+import android.view.View
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.LayoutManager
+import androidx.recyclerview.widget.RecyclerView.ViewHolder
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.android.launcher3.util.Executors
+import com.android.launcher3.views.ActivityContext
+import com.google.common.truth.Truth.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mock
+import org.mockito.Mockito.never
+import org.mockito.Mockito.spy
+import org.mockito.Mockito.times
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.`when`
+import org.mockito.MockitoAnnotations
+
+@SmallTest
+@RunWith(AndroidJUnit4::class)
+class AllAppsRecyclerViewPoolTest<T> where T : Context, T : ActivityContext {
+
+    private lateinit var underTest: AllAppsRecyclerViewPool<T>
+    private lateinit var adapter: RecyclerView.Adapter<*>
+
+    @Mock private lateinit var parent: RecyclerView
+    @Mock private lateinit var itemView: View
+    @Mock private lateinit var layoutManager: LayoutManager
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        underTest = spy(AllAppsRecyclerViewPool())
+        adapter =
+            object : RecyclerView.Adapter<ViewHolder>() {
+                override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+                    object : ViewHolder(itemView) {}
+
+                override fun getItemCount() = 0
+
+                override fun onBindViewHolder(holder: ViewHolder, position: Int) {}
+            }
+        underTest.setMaxRecycledViews(VIEW_TYPE, 20)
+        `when`(parent.layoutManager).thenReturn(layoutManager)
+    }
+
+    @Test
+    fun preinflate_success() {
+        underTest.preInflateAllAppsViewHolders(adapter, VIEW_TYPE, parent, 10) { 10 }
+
+        awaitTasksCompleted()
+        assertThat(underTest.getRecycledViewCount(VIEW_TYPE)).isEqualTo(10)
+    }
+
+    @Test
+    fun preinflate_not_triggered() {
+        underTest.preInflateAllAppsViewHolders(adapter, VIEW_TYPE, parent, 0) { 0 }
+
+        awaitTasksCompleted()
+        assertThat(underTest.getRecycledViewCount(VIEW_TYPE)).isEqualTo(0)
+    }
+
+    @Test
+    fun preinflate_cancel_before_runOnMainThread() {
+        underTest.preInflateAllAppsViewHolders(adapter, VIEW_TYPE, parent, 10) { 10 }
+        assertThat(underTest.mCancellableTask!!.canceled).isFalse()
+
+        underTest.clear()
+
+        awaitTasksCompleted()
+        verify(underTest, never()).putRecycledView(any(ViewHolder::class.java))
+        assertThat(underTest.mCancellableTask!!.canceled).isTrue()
+        assertThat(underTest.getRecycledViewCount(VIEW_TYPE)).isEqualTo(0)
+    }
+
+    @Test
+    fun preinflate_cancel_after_run() {
+        underTest.preInflateAllAppsViewHolders(adapter, VIEW_TYPE, parent, 10) { 10 }
+        assertThat(underTest.mCancellableTask!!.canceled).isFalse()
+        awaitTasksCompleted()
+
+        underTest.clear()
+
+        verify(underTest, times(10)).putRecycledView(any(ViewHolder::class.java))
+        assertThat(underTest.mCancellableTask!!.canceled).isTrue()
+        assertThat(underTest.getRecycledViewCount(VIEW_TYPE)).isEqualTo(0)
+    }
+
+    private fun awaitTasksCompleted() {
+        Executors.VIEW_PREINFLATION_EXECUTOR.submit<Any> { null }.get()
+        Executors.MAIN_EXECUTOR.submit<Any> { null }.get()
+    }
+
+    companion object {
+        private const val VIEW_TYPE: Int = 4
+    }
+}