Synchronize the app launch and taskbar stash animations.

Introduce FLAG_IGNORE_IN_APP to prevent taskbar from stashing prematurely
due to HomeTransitionListener signal.

Bug: 345768019
Fixes: 319162553
Test: Launch an app, note the two animations are synced
      Verified by locally introducing a startDelay (since otherwise it is hard to tell)
Flag: com.android.launcher3.enable_scaling_reveal_home_animation
Change-Id: Ibb64e0321f33cf81e337fc7c1b2c3edfb23e6ba4

quickstep/src/com/android/launcher3/QuickstepTransitionManager.java

@@ -356,6 +356,14 @@ public class QuickstepTransitionManager implements OnDeviceProfileChangeListener
         options.setOnAnimationAbortListener(endCallback);
         options.setOnAnimationFinishedListener(endCallback);
 
+        // Prepare taskbar for animation synchronization. This needs to happen here before any
+        // app transition is created.
+        LauncherTaskbarUIController taskbarController = mLauncher.getTaskbarUIController();
+        if (enableScalingRevealHomeAnimation() && taskbarController != null) {
+            taskbarController.setIgnoreInAppFlagForSync(true);
+            onEndCallback.add(() -> taskbarController.setIgnoreInAppFlagForSync(false));
+        }
+
         IBinder cookie = mAppLaunchRunner.supportsReturnTransition()
                 ? ((ContainerAnimationRunner) mAppLaunchRunner).getCookie() : null;
         addLaunchCookie(cookie, (ItemInfo) v.getTag(), options);
@@ -1912,6 +1920,21 @@ public class QuickstepTransitionManager implements OnDeviceProfileChangeListener
                 anim.addListener(mForceInvisibleListener);
             }
 
+            // Syncs the app launch animation and taskbar stash animation (if exists).
+            if (enableScalingRevealHomeAnimation()) {
+                LauncherTaskbarUIController taskbarController = mLauncher.getTaskbarUIController();
+                if (taskbarController != null) {
+                    taskbarController.setIgnoreInAppFlagForSync(false);
+
+                    if (launcherClosing) {
+                        Animator taskbar = taskbarController.createAnimToApp();
+                        if (taskbar != null) {
+                            anim.play(taskbar);
+                        }
+                    }
+                }
+            }
+
             result.setAnimation(anim, mLauncher, mOnEndCallback::executeAllAndDestroy,
                     skipFirstFrame);
         }

quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java

@@ -19,6 +19,7 @@ import static com.android.launcher3.QuickstepTransitionManager.TRANSIENT_TASKBAR
 import static com.android.launcher3.statemanager.BaseState.FLAG_NON_INTERACTIVE;
 import static com.android.launcher3.taskbar.TaskbarEduTooltipControllerKt.TOOLTIP_STEP_FEATURES;
 import static com.android.launcher3.taskbar.TaskbarLauncherStateController.FLAG_VISIBLE;
+import static com.android.launcher3.taskbar.TaskbarStashController.FLAG_IGNORE_IN_APP;
 import static com.android.quickstep.TaskAnimationManager.ENABLE_SHELL_TRANSITIONS;
 import static com.android.window.flags.Flags.enableDesktopWindowingWallpaperActivity;
 
@@ -256,6 +257,24 @@ public class LauncherTaskbarUIController extends TaskbarUIController {
         return mTaskbarLauncherStateController.createAnimToLauncher(toState, callbacks, duration);
     }
 
+    /**
+     * Create Taskbar animation to be played alongside the Launcher app launch animation.
+     */
+    public @Nullable Animator createAnimToApp() {
+        TaskbarStashController stashController = mControllers.taskbarStashController;
+        stashController.updateStateForFlag(TaskbarStashController.FLAG_IN_APP, true);
+        return stashController.createApplyStateAnimator(stashController.getStashDuration());
+    }
+
+    /**
+     * Temporarily ignore FLAG_IN_APP for app launches to prevent premature taskbar stashing.
+     * This is needed because taskbar gets a signal to stash before we actually start the
+     * app launch animation.
+     */
+    public void setIgnoreInAppFlagForSync(boolean enabled) {
+        mControllers.taskbarStashController.updateStateForFlag(FLAG_IGNORE_IN_APP, enabled);
+    }
+
     public void updateTaskbarLauncherStateGoingHome() {
         mTaskbarLauncherStateController.updateStateForFlag(FLAG_VISIBLE, true);
         mTaskbarLauncherStateController.applyState();

quickstep/src/com/android/launcher3/taskbar/TaskbarStashController.java

@@ -95,6 +95,7 @@ public class TaskbarStashController implements TaskbarControllers.LoggableTaskba
     public static final int FLAG_STASHED_SYSUI = 1 << 9; //  app pinning,...
     public static final int FLAG_STASHED_DEVICE_LOCKED = 1 << 10; // device is locked: keyguard, ...
     public static final int FLAG_IN_OVERVIEW = 1 << 11; // launcher is in overview
+    public static final int FLAG_IGNORE_IN_APP = 1 << 12; // used to sync with app launch animation
 
     // If any of these flags are enabled, isInApp should return true.
     private static final int FLAGS_IN_APP = FLAG_IN_APP | FLAG_IN_SETUP;
@@ -1263,6 +1264,11 @@ public class TaskbarStashController implements TaskbarControllers.LoggableTaskba
          */
         @Nullable
         public Animator createSetStateAnimator(long flags, long duration) {
+            // We do this when we want to synchronize the app launch and taskbar stash animations.
+            if (hasAnyFlag(FLAG_IGNORE_IN_APP) && hasAnyFlag(flags, FLAG_IN_APP)) {
+                flags = flags & ~FLAG_IN_APP;
+            }
+
             boolean isStashed = mStashCondition.test(flags);
 
             if (DEBUG) {