Fix an IllegalStateException in dream overlays.

Test: atest DreamOverlayServiceTest
Bug: 219908617
Change-Id: Id4eb877def0d1633cdc544881ea254d0b00263ae

packages/SystemUI/src/com/android/systemui/dreams/DreamOverlayService.java

@@ -19,6 +19,8 @@ package com.android.systemui.dreams;
 import android.content.Context;
 import android.graphics.drawable.ColorDrawable;
 import android.util.Log;
+import android.view.View;
+import android.view.ViewGroup;
 import android.view.Window;
 import android.view.WindowInsets;
 import android.view.WindowManager;
@@ -177,9 +179,26 @@ public class DreamOverlayService extends android.service.dreams.DreamOverlayServ
         }
 
         mDreamOverlayContainerViewController.init();
+        // Make extra sure the container view has been removed from its old parent (otherwise we
+        // risk an IllegalStateException in some cases when setting the container view as the
+        // window's content view and the container view hasn't been properly removed previously).
+        removeContainerViewFromParent();
         mWindow.setContentView(mDreamOverlayContainerViewController.getContainerView());
 
         final WindowManager windowManager = mContext.getSystemService(WindowManager.class);
         windowManager.addView(mWindow.getDecorView(), mWindow.getAttributes());
     }
+
+    private void removeContainerViewFromParent() {
+        View containerView = mDreamOverlayContainerViewController.getContainerView();
+        if (containerView == null) {
+            return;
+        }
+        ViewGroup parentView = (ViewGroup) containerView.getParent();
+        if (parentView == null) {
+            return;
+        }
+        Log.w(TAG, "Removing dream overlay container view parent!");
+        parentView.removeView(containerView);
+    }
 }

packages/SystemUI/tests/src/com/android/systemui/dreams/DreamOverlayServiceTest.java

@@ -28,6 +28,7 @@ import android.service.dreams.DreamService;
 import android.service.dreams.IDreamOverlay;
 import android.service.dreams.IDreamOverlayCallback;
 import android.testing.AndroidTestingRunner;
+import android.view.ViewGroup;
 import android.view.WindowManager;
 import android.view.WindowManagerImpl;
 
@@ -99,6 +100,9 @@ public class DreamOverlayServiceTest extends SysuiTestCase {
     @Mock
     DreamPreviewComplication mPreviewComplication;
 
+    @Mock
+    ViewGroup mDreamOverlayContainerViewParent;
+
     DreamOverlayService mService;
 
     @Before
@@ -151,6 +155,23 @@ public class DreamOverlayServiceTest extends SysuiTestCase {
         verify(mDreamOverlayContainerViewController).init();
     }
 
+    @Test
+    public void testDreamOverlayContainerViewRemovedFromOldParentWhenInitialized()
+            throws Exception {
+        when(mDreamOverlayContainerView.getParent())
+                .thenReturn(mDreamOverlayContainerViewParent)
+                .thenReturn(null);
+
+        final IBinder proxy = mService.onBind(new Intent());
+        final IDreamOverlay overlay = IDreamOverlay.Stub.asInterface(proxy);
+
+        // Inform the overlay service of dream starting.
+        overlay.startDream(mWindowParams, mDreamOverlayCallback);
+        mMainExecutor.runAllReady();
+
+        verify(mDreamOverlayContainerViewParent).removeView(mDreamOverlayContainerView);
+    }
+
     @Test
     public void testShouldShowComplicationsFalseByDefault() {
         mService.onBind(new Intent());