Associate starting window with task once a TF is added

Because the host activity of starting window may not be moved
into TaskFragment, and the order change from WCT is outside
the scope of transferring starting window.

Bug: 243120073
Test: atest ActivityRecordTests#testStartingWindowInTaskFragment
Change-Id: I8a052af72bf4c307e9d72e10ed47a7f8ffbdf847

services/core/java/com/android/server/wm/ActivityRecord.java

@@ -1582,13 +1582,6 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
         if (newParent != null && isState(RESUMED)) {
             newParent.setResumedActivity(this, "onParentChanged");
-            if (mStartingWindow != null && mStartingData != null
-                    && mStartingData.mAssociatedTask == null && newParent.isEmbedded()) {
-                // The starting window should keep covering its task when the activity is
-                // reparented to a task fragment that may not fill the task bounds.
-                associateStartingDataWithTask();
-                attachStartingSurfaceToAssociatedTask();
-            }
             mImeInsetsFrozenUntilStartInput = false;
         }
 
@@ -2679,14 +2672,17 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
         }
     }
 
+    /** Called when the starting window is added to this activity. */
     void attachStartingWindow(@NonNull WindowState startingWindow) {
         startingWindow.mStartingData = mStartingData;
         mStartingWindow = startingWindow;
+        // The snapshot type may have called associateStartingDataWithTask().
         if (mStartingData != null && mStartingData.mAssociatedTask != null) {
             attachStartingSurfaceToAssociatedTask();
         }
     }
 
+    /** Makes starting window always fill the associated task. */
     private void attachStartingSurfaceToAssociatedTask() {
         // Associate the configuration of starting window with the task.
         overrideConfigurationPropagation(mStartingWindow, mStartingData.mAssociatedTask);
@@ -2694,6 +2690,7 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
                 mStartingData.mAssociatedTask.mSurfaceControl);
     }
 
+    /** Called when the starting window is not added yet but its data is known to fill the task. */
     private void associateStartingDataWithTask() {
         mStartingData.mAssociatedTask = task;
         task.forAllActivities(r -> {
@@ -2703,6 +2700,16 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
         });
     }
 
+    /** Associates and attaches an added starting window to the current task. */
+    void associateStartingWindowWithTaskIfNeeded() {
+        if (mStartingWindow == null || mStartingData == null
+                || mStartingData.mAssociatedTask != null) {
+            return;
+        }
+        associateStartingDataWithTask();
+        attachStartingSurfaceToAssociatedTask();
+    }
+
     void removeStartingWindow() {
         boolean prevEligibleForLetterboxEducation = isEligibleForLetterboxEducation();
 

services/core/java/com/android/server/wm/Task.java

@@ -1433,6 +1433,13 @@ class Task extends TaskFragment {
         final TaskFragment childTaskFrag = child.asTaskFragment();
         if (childTaskFrag != null && childTaskFrag.asTask() == null) {
             childTaskFrag.setMinDimensions(mMinWidth, mMinHeight);
+
+            // The starting window should keep covering its task when a pure TaskFragment is added
+            // because its bounds may not fill the task.
+            final ActivityRecord top = getTopMostActivity();
+            if (top != null) {
+                top.associateStartingWindowWithTaskIfNeeded();
+            }
         }
     }
 

services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java

@@ -2868,6 +2868,7 @@ public class ActivityRecordTests extends WindowTestsBase {
                 mAtm, null /* fragmentToken */, false /* createdByOrganizer */);
         fragmentSetup.accept(taskFragment1, new Rect(0, 0, width / 2, height));
         task.addChild(taskFragment1, POSITION_TOP);
+        assertEquals(task, activity1.mStartingData.mAssociatedTask);
 
         final TaskFragment taskFragment2 = new TaskFragment(
                 mAtm, null /* fragmentToken */, false /* createdByOrganizer */);
@@ -2889,7 +2890,6 @@ public class ActivityRecordTests extends WindowTestsBase {
                 eq(task.mSurfaceControl));
         assertEquals(activity1.mStartingData, startingWindow.mStartingData);
         assertEquals(task.mSurfaceControl, startingWindow.getAnimationLeashParent());
-        assertEquals(task, activity1.mStartingData.mAssociatedTask);
         assertEquals(taskFragment1.getBounds(), activity1.getBounds());
         // The activity was resized by task fragment, but starting window must still cover the task.
         assertEquals(taskBounds, activity1.mStartingWindow.getBounds());
@@ -2897,7 +2897,6 @@ public class ActivityRecordTests extends WindowTestsBase {
         // The starting window is only removed when all embedded activities are drawn.
         final WindowState activityWindow = mock(WindowState.class);
         activity1.onFirstWindowDrawn(activityWindow);
-        assertNotNull(activity1.mStartingWindow);
         activity2.onFirstWindowDrawn(activityWindow);
         assertNull(activity1.mStartingWindow);
     }