Pre-inflate BubbleTextViews into Launcher/TaskBar All Apps RV

This CL ensures no inflation of BubbleTextView happens while binding applications, and reduces jank on slow device.

1. Let active/inactive all apps RVs share the same AllAppsRecyclerViewPool
2. Use worker thread to pre-inflate BubbleTextViews and add them to shared view pool on main thread

Bug: 287523421
Test: See before/after screenshot/video/trace attached in bug
Change-Id: I00213407be2c7c2d329997552785d0aa56c4d057

src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java

@@ -18,6 +18,7 @@ package com.android.launcher3.allapps;
 import static com.android.launcher3.allapps.ActivityAllAppsContainerView.AdapterHolder.SEARCH;
 import static com.android.launcher3.allapps.BaseAllAppsAdapter.VIEW_TYPE_WORK_DISABLED_CARD;
 import static com.android.launcher3.allapps.BaseAllAppsAdapter.VIEW_TYPE_WORK_EDU_CARD;
+import static com.android.launcher3.config.FeatureFlags.ENABLE_ALL_APPS_RV_PREINFLATION;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_COUNT;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_TAP_ON_PERSONAL_TAB;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_TAP_ON_WORK_TAB;
@@ -79,7 +80,6 @@ import com.android.launcher3.keyboard.FocusedItemDecorator;
 import com.android.launcher3.model.StringCache;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.testing.shared.TestProtocol;
-import com.android.launcher3.util.Executors;
 import com.android.launcher3.util.ItemInfoMatcher;
 import com.android.launcher3.util.Themes;
 import com.android.launcher3.views.ActivityContext;
@@ -141,7 +141,7 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
     private final SearchTransitionController mSearchTransitionController;
     private final Paint mHeaderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
     private final Rect mInsets = new Rect();
-    private final AllAppsStore mAllAppsStore = new AllAppsStore();
+    private final AllAppsStore mAllAppsStore;
     private final RecyclerView.OnScrollListener mScrollListener =
             new RecyclerView.OnScrollListener() {
                 @Override
@@ -194,6 +194,7 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
     public ActivityAllAppsContainerView(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         mActivityContext = ActivityContext.lookupContext(context);
+        mAllAppsStore = new AllAppsStore(mActivityContext);
 
         mScrimColor = Themes.getAttrColor(context, R.attr.allAppsScrimColor);
         mHeaderThreshold = getResources().getDimensionPixelSize(
@@ -559,6 +560,13 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
             mAH.get(AdapterHolder.MAIN).setup(mViewPager.getChildAt(0), mPersonalMatcher);
             mAH.get(AdapterHolder.WORK).setup(mViewPager.getChildAt(1), mWorkManager.getMatcher());
             mAH.get(AdapterHolder.WORK).mRecyclerView.setId(R.id.apps_list_view_work);
+            if (ENABLE_ALL_APPS_RV_PREINFLATION.get()) {
+                // Let main and work rv share same view pool.
+                ((RecyclerView) mViewPager.getChildAt(0))
+                        .setRecycledViewPool(mAllAppsStore.getRecyclerViewPool());
+                ((RecyclerView) mViewPager.getChildAt(1))
+                        .setRecycledViewPool(mAllAppsStore.getRecyclerViewPool());
+            }
             if (FeatureFlags.ENABLE_EXPANDING_PAUSE_WORK_BUTTON.get()) {
                 mAH.get(AdapterHolder.WORK).mRecyclerView.addOnScrollListener(
                         mWorkManager.newScrollListener());

src/com/android/launcher3/allapps/AllAppsStore.java

@@ -15,24 +15,30 @@
  */
 package com.android.launcher3.allapps;
 
+import static com.android.launcher3.config.FeatureFlags.ENABLE_ALL_APPS_RV_PREINFLATION;
 import static com.android.launcher3.model.data.AppInfo.COMPONENT_KEY_COMPARATOR;
 import static com.android.launcher3.model.data.AppInfo.EMPTY_ARRAY;
 import static com.android.launcher3.model.data.ItemInfoWithIcon.FLAG_SHOW_DOWNLOAD_PROGRESS_MASK;
 import static com.android.launcher3.testing.shared.TestProtocol.WORK_TAB_MISSING;
 
+import android.content.Context;
 import android.os.UserHandle;
 import android.util.Log;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.RecyclerView.RecycledViewPool;
 
 import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.model.data.ItemInfo;
+import com.android.launcher3.recyclerview.AllAppsRecyclerViewPool;
 import com.android.launcher3.testing.shared.TestProtocol;
 import com.android.launcher3.util.ComponentKey;
 import com.android.launcher3.util.PackageUserKey;
+import com.android.launcher3.views.ActivityContext;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -45,8 +51,10 @@ import java.util.function.Predicate;
 
 /**
  * A utility class to maintain the collection of all apps.
+ *
+ * @param <T> The type of the context.
  */
-public class AllAppsStore {
+public class AllAppsStore<T extends Context & ActivityContext> {
 
     // Defer updates flag used to defer all apps updates to the next draw.
     public static final int DEFER_UPDATES_NEXT_DRAW = 1 << 0;
@@ -64,20 +72,36 @@ public class AllAppsStore {
     private int mModelFlags;
     private int mDeferUpdatesFlags = 0;
     private boolean mUpdatePending = false;
+    private final AllAppsRecyclerViewPool mAllAppsRecyclerViewPool = new AllAppsRecyclerViewPool();
+
+    private final T mContext;
 
     public AppInfo[] getApps() {
         return mApps;
     }
 
+    public AllAppsStore(@NonNull T context) {
+        mContext = context;
+    }
+
     /**
      * Sets the current set of apps and sets mapping for {@link PackageUserKey} to Uid for
      * the current set of apps.
      */
-    public void setApps(AppInfo[] apps, int flags, Map<PackageUserKey, Integer> map) {
+    public void setApps(AppInfo[] apps, int flags, Map<PackageUserKey, Integer> map)  {
         mApps = apps;
         mModelFlags = flags;
         notifyUpdate();
         mPackageUserKeytoUidMap = map;
+        // Preinflate all apps RV when apps has changed, which can happen after unlocking screen,
+        // rotating screen, or downloading/upgrading apps.
+        if (ENABLE_ALL_APPS_RV_PREINFLATION.get()) {
+            mAllAppsRecyclerViewPool.preInflateAllAppsViewHolders(mContext);
+        }
+    }
+
+    RecycledViewPool getRecyclerViewPool() {
+        return mAllAppsRecyclerViewPool;
     }
 
     /**

src/com/android/launcher3/allapps/BaseAllAppsAdapter.java

@@ -32,8 +32,8 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.R;
-import com.android.launcher3.allapps.search.SearchAdapterProvider;
 import com.android.launcher3.Utilities;
+import com.android.launcher3.allapps.search.SearchAdapterProvider;
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.views.ActivityContext;

src/com/android/launcher3/config/FeatureFlags.java

@@ -401,6 +401,12 @@ public final class FeatureFlags {
             "ENABLE_RESPONSIVE_WORKSPACE", DISABLED,
             "Enables new workspace grid calculations method.");
 
+    // TODO(Block 33): Clean up flags
+
+    public static final BooleanFlag ENABLE_ALL_APPS_RV_PREINFLATION = getDebugFlag(288161355,
+            "ENABLE_ALL_APPS_RV_PREINFLATION", DISABLED,
+            "Enables preinflating all apps icons to avoid scrolling jank.");
+
     public static class BooleanFlag {
 
         private final boolean mCurrentValue;

src/com/android/launcher3/recyclerview/AllAppsRecyclerViewPool.kt

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2023 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 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.allapps.BaseAllAppsAdapter
+import com.android.launcher3.util.Executors.MAIN_EXECUTOR
+import com.android.launcher3.util.Executors.VIEW_PREINFLATION_EXECUTOR
+import com.android.launcher3.views.ActivityContext
+import java.util.concurrent.Future
+
+private const val PREINFLATE_ICONS_ROW_COUNT = 4
+private const val EXTRA_ICONS_COUNT = 2
+
+/**
+ * An [RecycledViewPool] that preinflates app icons ([ViewHolder] of [BubbleTextView]) of all apps
+ * [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() {
+
+    private var future: Future<Void>? = null
+
+    /**
+     * 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 {
+        val appsView = context.appsView ?: return
+        val activeRv: RecyclerView = appsView.activeRecyclerView ?: return
+        val preInflateCount = getPreinflateCount(context)
+        if (preInflateCount <= 0) {
+            return
+        }
+
+        // Because we perform onCreateViewHolder() on worker thread, we need a separate
+        // adapter/inflator object as they are not thread-safe. Note that the adapter
+        // just need to perform onCreateViewHolder(parent, VIEW_TYPE_ICON) so it doesn't need
+        // data source information.
+        val adapter: RecyclerView.Adapter<BaseAllAppsAdapter.ViewHolder> =
+            object : BaseAllAppsAdapter<T>(context, context.appsView.layoutInflater, null, null) {
+                override fun setAppsPerRow(appsPerRow: Int) = Unit
+                override fun getLayoutManager(): RecyclerView.LayoutManager? = null
+            }
+
+        // Inflate view holders on background thread, and added to view pool on main thread.
+        future?.cancel(true)
+        future =
+            VIEW_PREINFLATION_EXECUTOR.submit<Void> {
+                val viewHolders =
+                    Array(preInflateCount) {
+                        adapter.createViewHolder(activeRv, BaseAllAppsAdapter.VIEW_TYPE_ICON)
+                    }
+                MAIN_EXECUTOR.execute {
+                    for (i in 0 until minOf(viewHolders.size, getPreinflateCount(context))) {
+                        putRecycledView(viewHolders[i])
+                    }
+                }
+                null
+            }
+    }
+
+    /**
+     * After testing on phone, foldable and tablet, we found [PREINFLATE_ICONS_ROW_COUNT] rows of
+     * app icons plus [EXTRA_ICONS_COUNT] is the magic minimal count of app icons to preinflate to
+     * suffice fast scrolling.
+     */
+    fun <T> getPreinflateCount(context: T): Int where T : Context, T : ActivityContext {
+        val targetPreinflateCount =
+            PREINFLATE_ICONS_ROW_COUNT * context.deviceProfile.numShownAllAppsColumns +
+                EXTRA_ICONS_COUNT
+        val existingPreinflateCount = getRecycledViewCount(BaseAllAppsAdapter.VIEW_TYPE_ICON)
+        return targetPreinflateCount - existingPreinflateCount
+    }
+}

src/com/android/launcher3/util/Executors.java

@@ -21,6 +21,7 @@ import android.os.Process;
 
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
@@ -58,6 +59,11 @@ public class Executors {
             new LooperExecutor(
                     createAndStartNewLooper("UiThreadHelper", Process.THREAD_PRIORITY_FOREGROUND));
 
+
+    /** A background executor to preinflate views. */
+    public static final ExecutorService VIEW_PREINFLATION_EXECUTOR =
+            java.util.concurrent.Executors.newSingleThreadExecutor();
+
     /**
      * Utility method to get a started handler thread statically
      */