From 55f0c287b7578a58bc8b2874487b4fd920789508 Mon Sep 17 00:00:00 2001
From: Tony Huang <tonyychuang@google.com>
Date: Wed, 20 Jul 2022 17:25:00 +0800
Subject: [PATCH] Fix wrong split layout after drag drop

This cl fix two different issues but both belong to split layout
issue.

1. We will reset split layout after exitSplit, but when dismiss on
   non-onStageHasChildrenChange case, it reparent both split root
   children to TDA then no children remained. At this moment,
   onStageHasChildrenChange will callback and we will do
   flingDividerToDismiss and make layout change again then cause
   split layout wrong on next split active. This should be block
   by the active flag.
2. In some race condition, the applySurfaceChanges transtion might
   be merged to one transition and lead to surface bounds not set as
   our expectation. To avoid this issue, we should remove
   unnecessary applySurfaceChanges using.

Fix: 227142506
Test: manual
Test: pass existing tests
Change-Id: Id8741c88cf778a26fe39fa5c8223344a9bef4d46
---
 .../android/wm/shell/splitscreen/SplitScreenController.java   | 2 --
 .../com/android/wm/shell/splitscreen/StageCoordinator.java    | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
index 21bea4674805d..c1092dfa8d2e2 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
@@ -400,8 +400,6 @@ public class SplitScreenController implements DragAndDropPolicy.Starter,
                     return;
                 }
 
-                mStageCoordinator.updateSurfaceBounds(null /* layout */, t,
-                        false /* applyResizingOffset */);
                 for (int i = 0; i < apps.length; ++i) {
                     if (apps[i].mode == MODE_OPENING) {
                         t.show(apps[i].leash);
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 2229e26b93437..e9d1055356307 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
@@ -1211,7 +1211,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
     private void onStageHasChildrenChanged(StageListenerImpl stageListener) {
         final boolean hasChildren = stageListener.mHasChildren;
         final boolean isSideStage = stageListener == mSideStageListener;
-        if (!hasChildren && !mIsExiting) {
+        if (!hasChildren && !mIsExiting && mMainStage.isActive()) {
             if (isSideStage && mMainStageListener.mVisible) {
                 // Exit to main stage if side stage no longer has children.
                 if (ENABLE_SHELL_TRANSITIONS) {
@@ -1231,7 +1231,7 @@ public class StageCoordinator implements SplitLayout.SplitLayoutHandler,
                             EXIT_REASON_APP_FINISHED);
                 }
             }
-        } else if (isSideStage && !mMainStage.isActive()) {
+        } else if (isSideStage && hasChildren && !mMainStage.isActive()) {
             if (mFocusingTaskInfo != null && !isValidToEnterSplitScreen(mFocusingTaskInfo)) {
                 final WindowContainerTransaction wct = new WindowContainerTransaction();
                 mSideStage.removeAllTasks(wct, true);