Simplifying Launcher binding callbacks

> Making all methods as default
> Removing obsolete logic around synchronous binding
> Removing some UI dependencies from bind callbacks

Bug: 187353581
Test: Manual
Change-Id: I0d2bbb060af2cab7c64541d7695055629dfaf0b8
diff --git a/quickstep/robolectric_tests/src/com/android/launcher3/model/WidgetsPredicationUpdateTaskTest.java b/quickstep/robolectric_tests/src/com/android/launcher3/model/WidgetsPredicationUpdateTaskTest.java
index 5471e49..1386ac0 100644
--- a/quickstep/robolectric_tests/src/com/android/launcher3/model/WidgetsPredicationUpdateTaskTest.java
+++ b/quickstep/robolectric_tests/src/com/android/launcher3/model/WidgetsPredicationUpdateTaskTest.java
@@ -41,20 +41,11 @@
 import com.android.launcher3.icons.IconCache;
 import com.android.launcher3.model.BgDataModel.FixedContainerItems;
 import com.android.launcher3.model.QuickstepModelDelegate.PredictorState;
-import com.android.launcher3.model.data.AppInfo;
-import com.android.launcher3.model.data.ItemInfo;
-import com.android.launcher3.model.data.LauncherAppWidgetInfo;
-import com.android.launcher3.model.data.WorkspaceItemInfo;
 import com.android.launcher3.shadows.ShadowDeviceFlag;
-import com.android.launcher3.util.ComponentKey;
-import com.android.launcher3.util.IntArray;
 import com.android.launcher3.util.IntSet;
-import com.android.launcher3.util.ItemInfoMatcher;
 import com.android.launcher3.util.LauncherModelHelper;
-import com.android.launcher3.util.ViewOnDrawExecutor;
 import com.android.launcher3.widget.LauncherAppWidgetProviderInfo;
 import com.android.launcher3.widget.PendingAddWidgetInfo;
-import com.android.launcher3.widget.model.WidgetsListBaseEntry;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -68,9 +59,6 @@
 import org.robolectric.shadows.ShadowPackageManager;
 import org.robolectric.util.ReflectionHelpers;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -243,60 +231,5 @@
         public IntSet getPagesToBindSynchronously() {
             return IntSet.wrap(0);
         }
-
-        @Override
-        public void clearPendingBinds() { }
-
-        @Override
-        public void startBinding() { }
-
-        @Override
-        public void bindItems(List<ItemInfo> shortcuts, boolean forceAnimateIcons) { }
-
-        @Override
-        public void bindScreens(IntArray orderedScreenIds) { }
-
-        @Override
-        public void finishFirstPageBind(ViewOnDrawExecutor executor) { }
-
-        @Override
-        public void finishBindingItems(IntSet pagesBoundFirst) { }
-
-        @Override
-        public void preAddApps() { }
-
-        @Override
-        public void bindAppsAdded(IntArray newScreens, ArrayList<ItemInfo> addNotAnimated,
-                ArrayList<ItemInfo> addAnimated) { }
-
-        @Override
-        public void bindIncrementalDownloadProgressUpdated(AppInfo app) { }
-
-        @Override
-        public void bindWorkspaceItemsChanged(List<WorkspaceItemInfo> updated) { }
-
-        @Override
-        public void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets) { }
-
-        @Override
-        public void bindRestoreItemsChange(HashSet<ItemInfo> updates) { }
-
-        @Override
-        public void bindWorkspaceComponentsRemoved(ItemInfoMatcher matcher) { }
-
-        @Override
-        public void bindAllWidgets(List<WidgetsListBaseEntry> widgets) { }
-
-        @Override
-        public void onPagesBoundSynchronously(IntSet pages) { }
-
-        @Override
-        public void executeOnNextDraw(ViewOnDrawExecutor executor) { }
-
-        @Override
-        public void bindDeepShortcutMap(HashMap<ComponentKey, Integer> deepShortcutMap) { }
-
-        @Override
-        public void bindAllApplications(AppInfo[] apps, int flags) { }
     }
 }
diff --git a/robolectric_tests/src/com/android/launcher3/model/ModelMultiCallbacksTest.java b/robolectric_tests/src/com/android/launcher3/model/ModelMultiCallbacksTest.java
index 275cf81..07351fe 100644
--- a/robolectric_tests/src/com/android/launcher3/model/ModelMultiCallbacksTest.java
+++ b/robolectric_tests/src/com/android/launcher3/model/ModelMultiCallbacksTest.java
@@ -35,7 +35,7 @@
 import com.android.launcher3.util.LauncherLayoutBuilder;
 import com.android.launcher3.util.LauncherModelHelper;
 import com.android.launcher3.util.LooperExecutor;
-import com.android.launcher3.util.ViewOnDrawExecutor;
+import com.android.launcher3.util.RunnableList;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -106,14 +106,14 @@
         // No effect on callbacks when removing an callback
         mModelHelper.getModel().removeCallbacks(cb2);
         waitForLoaderAndTempMainThread();
-        assertNull(cb1.mDeferredExecutor);
-        assertNull(cb2.mDeferredExecutor);
+        assertNull(cb1.mPendingTasks);
+        assertNull(cb2.mPendingTasks);
 
         // Reloading only loads registered callbacks
         mModelHelper.getModel().startLoader();
         waitForLoaderAndTempMainThread();
         cb1.verifySynchronouslyBound(3);
-        assertNull(cb2.mDeferredExecutor);
+        assertNull(cb2.mPendingTasks);
     }
 
     @Test
@@ -180,19 +180,15 @@
         final List<ItemInfo> mItems = new ArrayList<>();
         IntSet mPageToBindSync = IntSet.wrap(0);
         IntSet mPageBoundSync = new IntSet();
-        ViewOnDrawExecutor mDeferredExecutor;
+        RunnableList mPendingTasks;
         AppInfo[] mAppInfos;
 
         MyCallbacks() { }
 
         @Override
-        public void onPagesBoundSynchronously(IntSet pages) {
-            mPageBoundSync = pages;
-        }
-
-        @Override
-        public void executeOnNextDraw(ViewOnDrawExecutor executor) {
-            mDeferredExecutor = executor;
+        public void onInitialBindComplete(IntSet boundPages, RunnableList pendingTasks) {
+            mPageBoundSync = boundPages;
+            mPendingTasks = pendingTasks;
         }
 
         @Override
@@ -213,19 +209,19 @@
         public void reset() {
             mItems.clear();
             mPageBoundSync = new IntSet();
-            mDeferredExecutor = null;
+            mPendingTasks = null;
             mAppInfos = null;
         }
 
         public void verifySynchronouslyBound(int totalItems) {
             // Verify that the requested page is bound synchronously
-            assertEquals(mPageBoundSync, mPageToBindSync);
+            assertEquals(mPageToBindSync, mPageBoundSync);
             assertEquals(mItems.size(), 1);
-            assertEquals(mItems.get(0).screenId, mPageBoundSync);
-            assertNotNull(mDeferredExecutor);
+            assertEquals(IntSet.wrap(mItems.get(0).screenId), mPageBoundSync);
+            assertNotNull(mPendingTasks);
 
             // Verify that all other pages are bound properly
-            mDeferredExecutor.runAllTasks();
+            mPendingTasks.executeAllAndDestroy();
             assertEquals(mItems.size(), totalItems);
         }
 
diff --git a/robolectric_tests/src/com/android/launcher3/util/LauncherUIHelper.java b/robolectric_tests/src/com/android/launcher3/util/LauncherUIHelper.java
index fdddab4..caad40e 100644
--- a/robolectric_tests/src/com/android/launcher3/util/LauncherUIHelper.java
+++ b/robolectric_tests/src/com/android/launcher3/util/LauncherUIHelper.java
@@ -81,7 +81,7 @@
         doLayout(launcher);
         ViewOnDrawExecutor executor = ReflectionHelpers.getField(launcher, "mPendingExecutor");
         if (executor != null) {
-            executor.runAllTasks();
+            executor.markCompleted();
         }
         return launcher;
     }
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 5a9257d..5720a8c 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -118,6 +118,7 @@
 import com.android.launcher3.allapps.AllAppsStore;
 import com.android.launcher3.allapps.AllAppsTransitionController;
 import com.android.launcher3.allapps.DiscoveryBounce;
+import com.android.launcher3.anim.AnimatorListeners;
 import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.compat.AccessibilityManagerCompat;
 import com.android.launcher3.config.FeatureFlags;
@@ -174,6 +175,7 @@
 import com.android.launcher3.util.PackageManagerHelper;
 import com.android.launcher3.util.PackageUserKey;
 import com.android.launcher3.util.PendingRequestArgs;
+import com.android.launcher3.util.RunnableList;
 import com.android.launcher3.util.SafeCloseable;
 import com.android.launcher3.util.SystemUiController;
 import com.android.launcher3.util.Themes;
@@ -2060,7 +2062,7 @@
     @Override
     public void clearPendingBinds() {
         if (mPendingExecutor != null) {
-            mPendingExecutor.markCompleted();
+            mPendingExecutor.cancel();
             mPendingExecutor = null;
 
             // We might have set this flag previously and forgot to clear it.
@@ -2482,25 +2484,6 @@
         return info;
     }
 
-    public void onPagesBoundSynchronously(IntSet pages) {
-        mSynchronouslyBoundPages = pages;
-        mWorkspace.setCurrentPage(pages.getArray().get(0));
-        mPagesToBindSynchronously = new IntSet();
-    }
-
-    @Override
-    public void executeOnNextDraw(ViewOnDrawExecutor executor) {
-        clearPendingBinds();
-        mPendingExecutor = executor;
-        if (!isInState(ALL_APPS)) {
-            mAppsView.getAppsStore().enableDeferUpdates(AllAppsStore.DEFER_UPDATES_NEXT_DRAW);
-            mPendingExecutor.execute(() -> mAppsView.getAppsStore().disableDeferUpdates(
-                    AllAppsStore.DEFER_UPDATES_NEXT_DRAW));
-        }
-
-        executor.attachTo(this);
-    }
-
     public void clearPendingExecutor(ViewOnDrawExecutor executor) {
         if (mPendingExecutor == executor) {
             mPendingExecutor = null;
@@ -2508,22 +2491,31 @@
     }
 
     @Override
-    public void finishFirstPageBind(final ViewOnDrawExecutor executor) {
+    public void onInitialBindComplete(IntSet boundPages, RunnableList pendingTasks) {
+        mSynchronouslyBoundPages = boundPages;
+        if (!boundPages.isEmpty()) {
+            mWorkspace.setCurrentPage(boundPages.getArray().get(0));
+        }
+        mPagesToBindSynchronously = new IntSet();
+
+        clearPendingBinds();
+        ViewOnDrawExecutor executor = new ViewOnDrawExecutor(pendingTasks);
+        mPendingExecutor = executor;
+        if (!isInState(ALL_APPS)) {
+            mAppsView.getAppsStore().enableDeferUpdates(AllAppsStore.DEFER_UPDATES_NEXT_DRAW);
+            pendingTasks.add(() -> mAppsView.getAppsStore().disableDeferUpdates(
+                    AllAppsStore.DEFER_UPDATES_NEXT_DRAW));
+        }
+
         AlphaProperty property = mDragLayer.getAlphaProperty(ALPHA_INDEX_LAUNCHER_LOAD);
         if (property.getValue() < 1) {
             ObjectAnimator anim = ObjectAnimator.ofFloat(property, MultiValueAlpha.VALUE, 1);
-            if (executor != null) {
-                anim.addListener(new AnimatorListenerAdapter() {
-                    @Override
-                    public void onAnimationEnd(Animator animation) {
-                        executor.onLoadAnimationCompleted();
-                    }
-                });
-            }
+            anim.addListener(AnimatorListeners.forEndCallback(executor::onLoadAnimationCompleted));
             anim.start();
-        } else if (executor != null) {
+        } else {
             executor.onLoadAnimationCompleted();
         }
+        executor.attachTo(this);
     }
 
     /**
diff --git a/src/com/android/launcher3/model/BaseLoaderResults.java b/src/com/android/launcher3/model/BaseLoaderResults.java
index 12ee676..30755e3 100644
--- a/src/com/android/launcher3/model/BaseLoaderResults.java
+++ b/src/com/android/launcher3/model/BaseLoaderResults.java
@@ -18,7 +18,9 @@
 
 import static com.android.launcher3.model.ModelUtils.filterCurrentWorkspaceItems;
 import static com.android.launcher3.model.ModelUtils.sortWorkspaceItemsSpatially;
+import static com.android.launcher3.util.Executors.MODEL_EXECUTOR;
 
+import android.os.Process;
 import android.util.Log;
 
 import com.android.launcher3.InvariantDeviceProfile;
@@ -33,7 +35,7 @@
 import com.android.launcher3.util.IntSet;
 import com.android.launcher3.util.LooperExecutor;
 import com.android.launcher3.util.LooperIdleLock;
-import com.android.launcher3.util.ViewOnDrawExecutor;
+import com.android.launcher3.util.RunnableList;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -175,7 +177,6 @@
                 currentScreenIndices = screenIndices;
             }
 
-            final boolean validFirstPage = !currentScreenIndices.isEmpty();
 
             IntSet currentScreenIds  = new IntSet();
             currentScreenIndices.forEach(
@@ -204,40 +205,25 @@
             // Bind workspace screens
             executeCallbacksTask(c -> c.bindScreens(mOrderedScreenIds), mUiExecutor);
 
-            Executor mainExecutor = mUiExecutor;
             // Load items on the current page.
-            bindWorkspaceItems(currentWorkspaceItems, mainExecutor);
-            bindAppWidgets(currentAppWidgets, mainExecutor);
+            bindWorkspaceItems(currentWorkspaceItems, mUiExecutor);
+            bindAppWidgets(currentAppWidgets, mUiExecutor);
             mExtraItems.forEach(item ->
-                    executeCallbacksTask(c -> c.bindExtraContainerItems(item), mainExecutor));
+                    executeCallbacksTask(c -> c.bindExtraContainerItems(item), mUiExecutor));
 
-            // In case of validFirstPage, only bind the first screen, and defer binding the
-            // remaining screens after first onDraw (and an optional the fade animation whichever
-            // happens later).
-            // This ensures that the first screen is immediately visible (eg. during rotation)
-            // In case of !validFirstPage, bind all pages one after other.
+            RunnableList pendingTasks = new RunnableList();
+            Executor pendingExecutor = pendingTasks::add;
+            bindWorkspaceItems(otherWorkspaceItems, pendingExecutor);
+            bindAppWidgets(otherAppWidgets, pendingExecutor);
+            executeCallbacksTask(c -> c.finishBindingItems(currentScreenIndices), pendingExecutor);
+            pendingExecutor.execute(
+                    () -> MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_DEFAULT));
 
-            final Executor deferredExecutor =
-                    validFirstPage ? new ViewOnDrawExecutor() : mainExecutor;
-
-            executeCallbacksTask(c -> c.finishFirstPageBind(
-                    validFirstPage ? (ViewOnDrawExecutor) deferredExecutor : null), mainExecutor);
-
-            bindWorkspaceItems(otherWorkspaceItems, deferredExecutor);
-            bindAppWidgets(otherAppWidgets, deferredExecutor);
-            // Tell the workspace that we're done binding items
-            executeCallbacksTask(c -> c.finishBindingItems(currentScreenIndices), deferredExecutor);
-
-            if (validFirstPage) {
-                executeCallbacksTask(c -> {
-                    // We are loading synchronously, which means, some of the pages will be
-                    // bound after first draw. Inform the mCallbacks that page binding is
-                    // not complete, and schedule the remaining pages.
-                    c.onPagesBoundSynchronously(currentScreenIndices);
-                    c.executeOnNextDraw((ViewOnDrawExecutor) deferredExecutor);
-
-                }, mUiExecutor);
-            }
+            executeCallbacksTask(
+                    c -> {
+                        MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
+                        c.onInitialBindComplete(currentScreenIndices, pendingTasks);
+                    }, mUiExecutor);
         }
 
         private void bindWorkspaceItems(
diff --git a/src/com/android/launcher3/model/BgDataModel.java b/src/com/android/launcher3/model/BgDataModel.java
index 0740a30..ba825ca 100644
--- a/src/com/android/launcher3/model/BgDataModel.java
+++ b/src/com/android/launcher3/model/BgDataModel.java
@@ -49,7 +49,7 @@
 import com.android.launcher3.util.IntSet;
 import com.android.launcher3.util.IntSparseArrayMap;
 import com.android.launcher3.util.ItemInfoMatcher;
-import com.android.launcher3.util.ViewOnDrawExecutor;
+import com.android.launcher3.util.RunnableList;
 import com.android.launcher3.widget.model.WidgetsListBaseEntry;
 
 import java.io.FileDescriptor;
@@ -462,35 +462,41 @@
          * Returns an IntSet of page numbers to bind first, synchronously if possible
          * or an empty IntSet
          */
-        IntSet getPagesToBindSynchronously();
-        void clearPendingBinds();
-        void startBinding();
-        void bindItems(List<ItemInfo> shortcuts, boolean forceAnimateIcons);
-        void bindScreens(IntArray orderedScreenIds);
-        void finishFirstPageBind(ViewOnDrawExecutor executor);
-        void finishBindingItems(IntSet pagesBoundFirst);
-        void preAddApps();
-        void bindAppsAdded(IntArray newScreens,
-                ArrayList<ItemInfo> addNotAnimated, ArrayList<ItemInfo> addAnimated);
+        default IntSet getPagesToBindSynchronously() {
+            return new IntSet();
+        }
+
+        default void clearPendingBinds() { }
+        default void startBinding() { }
+
+        default void bindItems(List<ItemInfo> shortcuts, boolean forceAnimateIcons) { }
+        default void bindScreens(IntArray orderedScreenIds) { }
+        default void finishBindingItems(IntSet pagesBoundFirst) { }
+        default void preAddApps() { }
+        default void bindAppsAdded(IntArray newScreens,
+                ArrayList<ItemInfo> addNotAnimated, ArrayList<ItemInfo> addAnimated) { }
 
         /**
          * Binds updated incremental download progress
          */
-        void bindIncrementalDownloadProgressUpdated(AppInfo app);
-        void bindWorkspaceItemsChanged(List<WorkspaceItemInfo> updated);
-        void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets);
-        void bindRestoreItemsChange(HashSet<ItemInfo> updates);
-        void bindWorkspaceComponentsRemoved(ItemInfoMatcher matcher);
-        void bindAllWidgets(List<WidgetsListBaseEntry> widgets);
-        void onPagesBoundSynchronously(IntSet pages);
-        void executeOnNextDraw(ViewOnDrawExecutor executor);
-        void bindDeepShortcutMap(HashMap<ComponentKey, Integer> deepShortcutMap);
+        default void bindIncrementalDownloadProgressUpdated(AppInfo app) { }
+        default void bindWorkspaceItemsChanged(List<WorkspaceItemInfo> updated) { }
+        default void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets) { }
+        default void bindRestoreItemsChange(HashSet<ItemInfo> updates) { }
+        default void bindWorkspaceComponentsRemoved(ItemInfoMatcher matcher) { }
+        default void bindAllWidgets(List<WidgetsListBaseEntry> widgets) { }
+
+        default void onInitialBindComplete(IntSet boundPages, RunnableList pendingTasks) {
+            pendingTasks.executeAllAndDestroy();
+        }
+
+        default void bindDeepShortcutMap(HashMap<ComponentKey, Integer> deepShortcutMap) { }
 
         /**
          * Binds extra item provided any external source
          */
         default void bindExtraContainerItems(FixedContainerItems item) { }
 
-        void bindAllApplications(AppInfo[] apps, int flags);
+        default void bindAllApplications(AppInfo[] apps, int flags) { }
     }
 }
diff --git a/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java b/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
index b271a6a..1a96c23 100644
--- a/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
+++ b/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
@@ -35,23 +35,13 @@
 import com.android.launcher3.model.data.AppInfo;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.ItemInfoWithIcon;
-import com.android.launcher3.model.data.LauncherAppWidgetInfo;
-import com.android.launcher3.model.data.WorkspaceItemInfo;
 import com.android.launcher3.popup.PopupContainerWithArrow;
 import com.android.launcher3.popup.PopupDataProvider;
 import com.android.launcher3.util.ComponentKey;
-import com.android.launcher3.util.IntArray;
-import com.android.launcher3.util.IntSet;
-import com.android.launcher3.util.ItemInfoMatcher;
 import com.android.launcher3.util.Themes;
-import com.android.launcher3.util.ViewOnDrawExecutor;
 import com.android.launcher3.views.BaseDragLayer;
-import com.android.launcher3.widget.model.WidgetsListBaseEntry;
 
-import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
 
 /**
  * Launcher activity for secondary displays
@@ -176,67 +166,10 @@
     }
 
     @Override
-    public IntSet getPagesToBindSynchronously() {
-        return new IntSet();
-    }
-
-    @Override
-    public void clearPendingBinds() { }
-
-    @Override
-    public void startBinding() { }
-
-    @Override
-    public void bindItems(List<ItemInfo> shortcuts, boolean forceAnimateIcons) { }
-
-    @Override
-    public void bindScreens(IntArray orderedScreenIds) { }
-
-    @Override
-    public void finishFirstPageBind(ViewOnDrawExecutor executor) {
-        if (executor != null) {
-            executor.onLoadAnimationCompleted();
-        }
-    }
-
-    @Override
-    public void finishBindingItems(IntSet pagesBoundFirst) { }
-
-    @Override
-    public void preAddApps() { }
-
-    @Override
-    public void bindAppsAdded(IntArray newScreens, ArrayList<ItemInfo> addNotAnimated,
-            ArrayList<ItemInfo> addAnimated) { }
-
-    @Override
     public void bindIncrementalDownloadProgressUpdated(AppInfo app) {
         mAppsView.getAppsStore().updateProgressBar(app);
     }
 
-    @Override
-    public void bindWorkspaceItemsChanged(List<WorkspaceItemInfo> updated) { }
-
-    @Override
-    public void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets) { }
-
-    @Override
-    public void bindRestoreItemsChange(HashSet<ItemInfo> updates) { }
-
-    @Override
-    public void bindWorkspaceComponentsRemoved(ItemInfoMatcher matcher) { }
-
-    @Override
-    public void bindAllWidgets(List<WidgetsListBaseEntry> widgets) { }
-
-    @Override
-    public void onPagesBoundSynchronously(IntSet pages) { }
-
-    @Override
-    public void executeOnNextDraw(ViewOnDrawExecutor executor) {
-        executor.attachTo(getDragLayer(), false, null);
-    }
-
     /**
      * Called when apps-button is clicked
      */
diff --git a/src/com/android/launcher3/util/ViewOnDrawExecutor.java b/src/com/android/launcher3/util/ViewOnDrawExecutor.java
index 82e24c2..5d90291 100644
--- a/src/com/android/launcher3/util/ViewOnDrawExecutor.java
+++ b/src/com/android/launcher3/util/ViewOnDrawExecutor.java
@@ -16,28 +16,21 @@
 
 package com.android.launcher3.util;
 
-import static com.android.launcher3.util.Executors.MODEL_EXECUTOR;
-
-import android.os.Process;
 import android.view.View;
 import android.view.View.OnAttachStateChangeListener;
 import android.view.ViewTreeObserver.OnDrawListener;
 
-import androidx.annotation.VisibleForTesting;
-
 import com.android.launcher3.Launcher;
 
-import java.util.ArrayList;
-import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 
 /**
  * An executor which runs all the tasks after the first onDraw is called on the target view.
  */
-public class ViewOnDrawExecutor implements Executor, OnDrawListener, Runnable,
+public class ViewOnDrawExecutor implements OnDrawListener, Runnable,
         OnAttachStateChangeListener {
 
-    private final ArrayList<Runnable> mTasks = new ArrayList<>();
+    private final RunnableList mTasks;
 
     private Consumer<ViewOnDrawExecutor> mOnClearCallback;
     private View mAttachedView;
@@ -46,22 +39,16 @@
     private boolean mLoadAnimationCompleted;
     private boolean mFirstDrawCompleted;
 
-    public void attachTo(Launcher launcher) {
-        attachTo(launcher.getWorkspace(), true /* waitForLoadAnimation */,
-                launcher::clearPendingExecutor);
+    private boolean mCancelled;
+
+    public ViewOnDrawExecutor(RunnableList tasks) {
+        mTasks = tasks;
     }
 
-    /**
-     * Attached the executor to the existence of the view
-     */
-    public void attachTo(View attachedView, boolean waitForLoadAnimation,
-            Consumer<ViewOnDrawExecutor> onClearCallback) {
-        mOnClearCallback = onClearCallback;
-        mAttachedView = attachedView;
+    public void attachTo(Launcher launcher) {
+        mOnClearCallback = launcher::clearPendingExecutor;
+        mAttachedView = launcher.getWorkspace();
         mAttachedView.addOnAttachStateChangeListener(this);
-        if (!waitForLoadAnimation) {
-            mLoadAnimationCompleted = true;
-        }
 
         if (mAttachedView.isAttachedToWindow()) {
             attachObserver();
@@ -75,12 +62,6 @@
     }
 
     @Override
-    public void execute(Runnable command) {
-        mTasks.add(command);
-        MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
-    }
-
-    @Override
     public void onViewAttachedToWindow(View v) {
         attachObserver();
     }
@@ -105,12 +86,17 @@
     public void run() {
         // Post the pending tasks after both onDraw and onLoadAnimationCompleted have been called.
         if (mLoadAnimationCompleted && mFirstDrawCompleted && !mCompleted) {
-            runAllTasks();
+            markCompleted();
         }
     }
 
+    /**
+     * Executes all tasks immediately
+     */
     public void markCompleted() {
-        mTasks.clear();
+        if (!mCancelled) {
+            mTasks.executeAllAndDestroy();
+        }
         mCompleted = true;
         if (mAttachedView != null) {
             mAttachedView.getViewTreeObserver().removeOnDrawListener(this);
@@ -119,21 +105,10 @@
         if (mOnClearCallback != null) {
             mOnClearCallback.accept(this);
         }
-        MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_DEFAULT);
     }
 
-    protected boolean isCompleted() {
-        return mCompleted;
-    }
-
-    /**
-     * Executes all tasks immediately
-     */
-    @VisibleForTesting
-    public void runAllTasks() {
-        for (final Runnable r : mTasks) {
-            r.run();
-        }
+    public void cancel() {
+        mCancelled = true;
         markCompleted();
     }
 }