From 1b9752dde8f6af685ecb73bc1c3f90114207ccfc Mon Sep 17 00:00:00 2001
From: Jerry Chang <chenghsiuchang@google.com>
Date: Thu, 2 Mar 2023 11:01:11 +0000
Subject: [PATCH] Fix splitting with wrong apps when entering split with
 rotation

This reland Ic4ed1b9f and adds back isSplitActive check.
Use mSplitRequest to determine if it's entering split instead, rename
the flag to mIsDividerRemoteAnimating which is more accurate to what it
stands for. When reseting divider remote animating flag, it should not
affect other logic for entering split screen besides divider visibility.

Fix: 269712647
Test: atest WMShellUnitTests WMShellFlickerTests NexusLauncherTests
Test: repro steps of the bug
Change-Id: Ie04c38722984b620bb14e11e75b9b04e75f6c39f
---
 .../shell/splitscreen/StageCoordinator.java   | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
index a6733843d4c36..7d3e7ca671e5c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
@@ -204,7 +204,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
     // and exit, since exit itself can trigger a number of changes that update the stages.
     private boolean mShouldUpdateRecents;
     private boolean mExitSplitScreenOnHide;
-    private boolean mIsSplitEntering;
+    private boolean mIsDividerRemoteAnimating;
     private boolean mIsDropEntering;
     private boolean mIsExiting;
 
@@ -881,7 +881,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
 
         // Set false to avoid record new bounds with old task still on top;
         mShouldUpdateRecents = false;
-        mIsSplitEntering = true;
+        mIsDividerRemoteAnimating = true;
         if (mSplitRequest == null) {
             mSplitRequest = new SplitRequest(mainTaskId,
                     mainPendingIntent != null ? mainPendingIntent.getIntent() : null,
@@ -974,7 +974,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
     }
 
     private void onRemoteAnimationFinishedOrCancelled(WindowContainerTransaction evictWct) {
-        mIsSplitEntering = false;
+        mIsDividerRemoteAnimating = false;
         mShouldUpdateRecents = true;
         mSplitRequest = null;
         // If any stage has no child after animation finished, it means that split will display
@@ -1240,7 +1240,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
             }
         });
         mShouldUpdateRecents = false;
-        mIsSplitEntering = false;
+        mIsDividerRemoteAnimating = false;
 
         mSplitLayout.getInvisibleBounds(mTempRect1);
         if (childrenToTop == null || childrenToTop.getTopVisibleChildTaskId() == INVALID_TASK_ID) {
@@ -1573,7 +1573,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
                 && !ENABLE_SHELL_TRANSITIONS) {
             // Clear the divider remote animating flag as the divider will be re-rendered to apply
             // the new rotation config.
-            mIsSplitEntering = false;
+            mIsDividerRemoteAnimating = false;
             mSplitLayout.update(null /* t */);
             onLayoutSizeChanged(mSplitLayout);
         }
@@ -1623,9 +1623,9 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
     }
 
     void onChildTaskAppeared(StageListenerImpl stageListener, int taskId) {
+        // Handle entering split screen while there is a split pair running in the background.
         if (stageListener == mSideStageListener && !isSplitScreenVisible() && isSplitActive()
-                && !mIsSplitEntering) {
-            // Handle entring split case here if split already running background.
+                && mSplitRequest == null) {
             if (mIsDropEntering) {
                 mSplitLayout.resetDividerPosition();
             } else {
@@ -1717,7 +1717,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
         mDividerVisible = visible;
         sendSplitVisibilityChanged();
 
-        if (mIsSplitEntering) {
+        if (mIsDividerRemoteAnimating) {
             ProtoLog.d(ShellProtoLogGroup.WM_SHELL_SPLIT_SCREEN,
                     "   Skip animating divider bar due to it's remote animating.");
             return;
@@ -1737,7 +1737,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
                     "   Skip animating divider bar due to divider leash not ready.");
             return;
         }
-        if (mIsSplitEntering) {
+        if (mIsDividerRemoteAnimating) {
             ProtoLog.d(ShellProtoLogGroup.WM_SHELL_SPLIT_SCREEN,
                     "   Skip animating divider bar due to it's remote animating.");
             return;
@@ -1805,7 +1805,8 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
                 mSplitLayout.flingDividerToDismiss(
                         mSideStagePosition != SPLIT_POSITION_BOTTOM_OR_RIGHT,
                         EXIT_REASON_APP_FINISHED);
-            } else if (!isSplitScreenVisible() && !mIsSplitEntering) {
+            } else if (!isSplitScreenVisible() && mSplitRequest == null) {
+                // Dismiss split screen in the background once any sides of the split become empty.
                 exitSplitScreen(null /* childrenToTop */, EXIT_REASON_APP_FINISHED);
             }
         } else if (isSideStage && hasChildren && !mMainStage.isActive()) {