From 357f68275cfd394cc097e4cedad55aeeeea021c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Ciche=C5=84ski?= <mateuszc@google.com>
Date: Fri, 16 Jun 2023 21:12:29 +0000
Subject: [PATCH] Reparent PiP overlay under task as soon as possible

For enter PiP animations started from Launcher, we send the signal to
WMShell to reparent the overlay under task as soon as possible.

This avoids flicker issue caused by race condition of cleaning up the
transition leash before the reparenting was done, which made the issue
of overlay being not attached to anything for few frames.

Bug: 281711939
Test: winscope trace from comment#28, leash follows task
Test: after http://recall/-/ekEuGtt9d9HWqkUtAzpHx8/ewrarENSYYOmUCa0b3fdtp

Change-Id: Ia16afd49a94d9ba8456287c2cdffb2a84e5a2bc7
---
 .../android/quickstep/AbsSwipeUpHandler.java  | 20 ++++++++++++++-----
 .../com/android/quickstep/SystemUiProxy.java  |  6 +++---
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
index 6ab3bbe778..95672f3ccb 100644
--- a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
+++ b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
@@ -1530,6 +1530,21 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
                 if (mSwipePipToHomeReleaseCheck != null) {
                     mSwipePipToHomeReleaseCheck.setCanRelease(false);
                 }
+
+                // grab a screenshot before the PipContentOverlay gets parented on top of the task
+                UI_HELPER_EXECUTOR.execute(() -> {
+                    final int taskId = mGestureState.getRunningTaskId();
+                    mTaskSnapshotCache.put(taskId,
+                            mRecentsAnimationController.screenshotTask(taskId));
+                });
+
+                // let SystemUi reparent the overlay leash as soon as possible
+                SystemUiProxy.INSTANCE.get(mContext).stopSwipePipToHome(
+                        mSwipePipToHomeAnimator.getTaskId(),
+                        mSwipePipToHomeAnimator.getComponentName(),
+                        mSwipePipToHomeAnimator.getDestinationBounds(),
+                        mSwipePipToHomeAnimator.getContentOverlay());
+
                 windowAnim = mSwipePipToHomeAnimators;
             } else {
                 mSwipePipToHomeAnimator = null;
@@ -2108,11 +2123,6 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
      */
     private void maybeFinishSwipePipToHome() {
         if (mIsSwipingPipToHome && mSwipePipToHomeAnimators[0] != null) {
-            SystemUiProxy.INSTANCE.get(mContext).stopSwipePipToHome(
-                    mSwipePipToHomeAnimator.getTaskId(),
-                    mSwipePipToHomeAnimator.getComponentName(),
-                    mSwipePipToHomeAnimator.getDestinationBounds(),
-                    mSwipePipToHomeAnimator.getContentOverlay());
             mRecentsAnimationController.setFinishTaskTransaction(
                     mSwipePipToHomeAnimator.getTaskId(),
                     mSwipePipToHomeAnimator.getFinishTransaction(),
diff --git a/quickstep/src/com/android/quickstep/SystemUiProxy.java b/quickstep/src/com/android/quickstep/SystemUiProxy.java
index d40558c585..dd6499bebf 100644
--- a/quickstep/src/com/android/quickstep/SystemUiProxy.java
+++ b/quickstep/src/com/android/quickstep/SystemUiProxy.java
@@ -563,9 +563,9 @@ public class SystemUiProxy implements ISystemUiProxy {
     }
 
     /**
-     * Notifies WM Shell that launcher has finished all the animation for swipe to home. WM Shell
-     * can choose to fade out the overlay when entering PIP is finished, and WM Shell should be
-     * responsible for cleaning up the overlay.
+     * Notifies WM Shell that launcher has finished the preparation of the animation for swipe to
+     * home. WM Shell can choose to fade out the overlay when entering PIP is finished, and WM Shell
+     * should be responsible for cleaning up the overlay.
      */
     public void stopSwipePipToHome(int taskId, ComponentName componentName, Rect destinationBounds,
             SurfaceControl overlay) {