Fix side stage cannot be focused

When split active by drag drop, the active point is
onStageHasChildrenChanged callback but we don't reorder side stage
to top then make it cannot be focused.

Add reorder root to top for fixing.

Fix: 204510713
Test: manual
Test: pass existing tests
Change-Id: I553a57250c302ff435a35c9a10599fc375e48248

2 files changed, 6 insertions, 1 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SideStage.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SideStage.java
index 51104e44569e..d67f4a6077b6 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SideStage.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SideStage.java
@@ -45,6 +45,11 @@ class SideStage extends StageTaskListener {
                 stageTaskUnfoldController);
     }
 
+    void moveToTop(Rect rootBounds, WindowContainerTransaction wct) {
+        final WindowContainerToken rootToken = mRootTaskInfo.token;
+        wct.setBounds(rootToken, rootBounds).reorder(rootToken, true /* onTop */);
+    }
+
     void addTask(ActivityManager.RunningTaskInfo task, Rect rootBounds,
             WindowContainerTransaction wct) {
         final WindowContainerToken rootToken = mRootTaskInfo.token;
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 3b62afc7320e..2cca41153ef0 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
@@ -758,7 +758,7 @@ class StageCoordinator implements SplitLayout.SplitLayoutHandler,
             final WindowContainerTransaction wct = new WindowContainerTransaction();
             // Make sure the main stage is active.
             mMainStage.activate(getMainStageBounds(), wct, true /* reparent */);
-            mSideStage.setBounds(getSideStageBounds(), wct);
+            mSideStage.moveToTop(getSideStageBounds(), wct);
             mTaskOrganizer.applyTransaction(wct);
         }
         if (!mLogger.hasStartedSession() && mMainStageListener.mHasChildren