From 679b570b74aa9f4963e1960989e2ae12a28bc52d Mon Sep 17 00:00:00 2001
From: Jerry Chang <chenghsiuchang@google.com>
Date: Wed, 22 Feb 2023 12:18:11 +0000
Subject: [PATCH] Fix splitting with wrong apps when entering split with
 rotation

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
Test: repro steps of the bug
Change-Id: Ic4ed1b9f96bd96c7f52a7f1d64ddbad0d4b76b12
---
 .../shell/splitscreen/StageCoordinator.java   | 23 ++++++++++---------
 1 file changed, 12 insertions(+), 11 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 f102f8e2f5dff..00ac8693750d1 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) {
-        if (stageListener == mSideStageListener && !isSplitScreenVisible() && isSplitActive()
-                && !mIsSplitEntering) {
-            // Handle entring split case here if split already running background.
+        // Handle entering split screen while there is a split pair running in the background.
+        if (stageListener == mSideStageListener && !isSplitScreenVisible()
+                && 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()) {