Fix SUW unstash animation.

- Defer any UI updates to taskbar after the SUW unstash animation is created.
- Predicted app icons take longer to load, so it's possible that they are
  added after the animation is created.
- This avoids the case where icons are seemingly in the taskbar but
  do not get animated like the rest of the icons.

- We also need to call onAnimationStart for the reveal animation immediately,
  otherwise the clipToOutline params never get set.

Bug: 277712185
Test: flash device, very quickly go through SUW
Change-Id: I4c3089da0d20bf91672e2305655c4c37b1f367aa

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

@@ -54,6 +54,10 @@ public class TaskbarModelCallbacks implements
     // Initialized in init.
     private TaskbarControllers mControllers;
 
+    // Used to defer any UI updates during the SUW unstash animation.
+    private boolean mDeferUpdatesForSUW;
+    private Runnable mDeferredUpdates;
+
     public TaskbarModelCallbacks(
             TaskbarActivityContext context, TaskbarView container) {
         mContext = context;
@@ -194,10 +198,38 @@ public class TaskbarModelCallbacks implements
         }
         hotseatItemInfos = mControllers.taskbarRecentAppsController
                 .updateHotseatItemInfos(hotseatItemInfos);
+
+        if (mDeferUpdatesForSUW) {
+            ItemInfo[] finalHotseatItemInfos = hotseatItemInfos;
+            mDeferredUpdates = () -> {
+                updateHotseatItemsAndBackground(finalHotseatItemInfos);
+            };
+        } else {
+            updateHotseatItemsAndBackground(hotseatItemInfos);
+        }
+    }
+
+    private void updateHotseatItemsAndBackground(ItemInfo[] hotseatItemInfos) {
         mContainer.updateHotseatItems(hotseatItemInfos);
         mControllers.taskbarViewController.updateIconsBackground();
     }
 
+    /**
+     * This is used to defer UI updates after SUW builds the unstash animation.
+     * @param defer if true, defers updates to the UI
+     *              if false, posts updates (if any) to the UI
+     */
+    public void setDeferUpdatesForSUW(boolean defer) {
+        mDeferUpdatesForSUW = defer;
+
+        if (!mDeferUpdatesForSUW) {
+            if (mDeferredUpdates != null) {
+                mContainer.post(mDeferredUpdates);
+                mDeferredUpdates = null;
+            }
+        }
+    }
+
     @Override
     public void onRunningTasksChanged() {
         updateRunningApps();
@@ -232,5 +264,7 @@ public class TaskbarModelCallbacks implements
             pw.println(
                     String.format("%s\tpredicted items count=%s", prefix, mPredictedItems.size()));
         }
+        pw.println(String.format("%s\tmDeferUpdatesForSUW=%b", prefix, mDeferUpdatesForSUW));
+        pw.println(String.format("%s\tupdates pending=%b", prefix, (mDeferredUpdates != null)));
     }
 }