From 371717ffcac2e5342d318141f4408ddc36b65596 Mon Sep 17 00:00:00 2001
From: Evan Rosky <erosky@google.com>
Date: Tue, 10 May 2022 15:52:15 -0700
Subject: [PATCH] Don't send redundant WCT for exit-pip finishTransition

exit-pip reaches the end state at the beginning of the transition,
sending another WCT at finish can erroneously interleave with
other transitions (esp. other pip transitions) causing the system
to end up in a bad state because it can effectively re-apply
the expand-pip WCT after a transition it was originally ahead of.
It is also redundant.

Bug: 231150615
Test: atest PinnedStackTests#testPipUnPipOverHome
Change-Id: Ica657d7d610226a09f34375685ed4089a63d4e92
---
 .../android/wm/shell/pip/PipTransition.java   | 49 ++++++++-----------
 1 file changed, 21 insertions(+), 28 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
index dfd34f8b7bc64..9adfbfeb8b28f 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
@@ -336,11 +336,27 @@ public class PipTransition extends PipTransitionController {
         // (likely a remote like launcher), so don't fire the finish-callback here -- wait until
         // the exit transition is merged.
         if ((mExitTransition == null || isAnimatingLocally()) && mFinishCallback != null) {
-            WindowContainerTransaction wct = new WindowContainerTransaction();
-            prepareFinishResizeTransaction(taskInfo, destinationBounds,
-                    direction, wct);
-            if (tx != null) {
-                wct.setBoundsChangeTransaction(taskInfo.token, tx);
+            WindowContainerTransaction wct = null;
+            if (isOutPipDirection(direction)) {
+                // Only need to reset surface properties. The server-side operations were already
+                // done at the start.
+                if (tx != null) {
+                    mFinishTransaction.merge(tx);
+                }
+            } else {
+                wct = new WindowContainerTransaction();
+                if (isInPipDirection(direction)) {
+                    // If we are animating from fullscreen using a bounds animation, then reset the
+                    // activity windowing mode, and set the task bounds to the final bounds
+                    wct.setActivityWindowingMode(taskInfo.token, WINDOWING_MODE_UNDEFINED);
+                    wct.scheduleFinishEnterPip(taskInfo.token, destinationBounds);
+                    wct.setBounds(taskInfo.token, destinationBounds);
+                } else {
+                    wct.setBounds(taskInfo.token, null /* bounds */);
+                }
+                if (tx != null) {
+                    wct.setBoundsChangeTransaction(taskInfo.token, tx);
+                }
             }
             final SurfaceControl leash = mPipOrganizer.getSurfaceControl();
             final int displayRotation = taskInfo.getConfiguration().windowConfiguration
@@ -876,27 +892,4 @@ public class PipTransition extends PipTransitionController {
         mPipMenuController.movePipMenu(null, null, destinationBounds);
         mPipMenuController.updateMenuBounds(destinationBounds);
     }
-
-    private void prepareFinishResizeTransaction(TaskInfo taskInfo, Rect destinationBounds,
-            @PipAnimationController.TransitionDirection int direction,
-            WindowContainerTransaction wct) {
-        Rect taskBounds = null;
-        if (isInPipDirection(direction)) {
-            // If we are animating from fullscreen using a bounds animation, then reset the
-            // activity windowing mode set by WM, and set the task bounds to the final bounds
-            taskBounds = destinationBounds;
-            wct.setActivityWindowingMode(taskInfo.token, WINDOWING_MODE_UNDEFINED);
-            wct.scheduleFinishEnterPip(taskInfo.token, destinationBounds);
-        } else if (isOutPipDirection(direction)) {
-            // If we are animating to fullscreen, then we need to reset the override bounds
-            // on the task to ensure that the task "matches" the parent's bounds.
-            taskBounds = (direction == TRANSITION_DIRECTION_LEAVE_PIP)
-                    ? null : destinationBounds;
-            wct.setWindowingMode(taskInfo.token, getOutPipWindowingMode());
-            // Simply reset the activity mode set prior to the animation running.
-            wct.setActivityWindowingMode(taskInfo.token, WINDOWING_MODE_UNDEFINED);
-        }
-
-        wct.setBounds(taskInfo.token, taskBounds);
-    }
 }