Updates visibility before trying to notify task stack changes

The previous activity would be immediately paused while starting
a resume-while-pausing activity, but we did not notify the
task stack changes to the listeners because the activity visibilities
weren't updated yet.

Bug: 154447447
Test: atest TaskStackChangedListenerTest

Change-Id: Id5da1c8f0fdf755341381bf49d8f48f396eebb55

3 files changed, 29 insertions, 2 deletions

diff --git a/services/core/java/com/android/server/wm/ActivityStack.java b/services/core/java/com/android/server/wm/ActivityStack.java
index db5e97250cd2..4860a8ee3ea1 100644
--- a/services/core/java/com/android/server/wm/ActivityStack.java
+++ b/services/core/java/com/android/server/wm/ActivityStack.java
@@ -1334,6 +1334,8 @@ class ActivityStack extends Task {
             prev.cpuTimeAtResume = 0; // reset it
         }
 
+        mRootWindowContainer.ensureActivitiesVisible(resuming, 0, !PRESERVE_WINDOWS);
+
         // Notify when the task stack has changed, but only if visibilities changed (not just
         // focus). Also if there is an active pinned stack - we always want to notify it about
         // task stack changes, because its positioning may depend on it.
@@ -1342,8 +1344,6 @@ class ActivityStack extends Task {
             mAtmService.getTaskChangeNotificationController().notifyTaskStackChanged();
             mStackSupervisor.mAppVisibilitiesChangedSinceLastPause = false;
         }
-
-        mRootWindowContainer.ensureActivitiesVisible(resuming, 0, !PRESERVE_WINDOWS);
     }
 
     boolean isTopStackInDisplayArea() {
diff --git a/services/tests/wmtests/AndroidManifest.xml b/services/tests/wmtests/AndroidManifest.xml
index fdc9401a66b0..f382fbae9280 100644
--- a/services/tests/wmtests/AndroidManifest.xml
+++ b/services/tests/wmtests/AndroidManifest.xml
@@ -58,6 +58,8 @@
                   android:screenOrientation="sensorLandscape"
                   android:showWhenLocked="true"
                   android:turnScreenOn="true" />
+        <activity android:name="com.android.server.wm.TaskStackChangedListenerTest$ResumeWhilePausingActivity"
+                  android:resumeWhilePausing="true"/>
         <activity android:name="com.android.server.wm.ScreenDecorWindowTests$TestActivity"
                   android:showWhenLocked="true" android:allowEmbedded="true"/>
     </application>
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskStackChangedListenerTest.java b/services/tests/wmtests/src/com/android/server/wm/TaskStackChangedListenerTest.java
index 4e92ea0f82e6..965edd4f8b11 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskStackChangedListenerTest.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskStackChangedListenerTest.java
@@ -81,6 +81,7 @@ public class TaskStackChangedListenerTest {
     @Before
     public void setUp() throws Exception {
         mService = ActivityManager.getService();
+        sTaskStackChangedCalled = false;
     }
 
     @After
@@ -114,6 +115,28 @@ public class TaskStackChangedListenerTest {
 
     @Test
     @Presubmit
+    public void testTaskStackChanged_resumeWhilePausing() throws Exception {
+        registerTaskStackChangedListener(new TaskStackListener() {
+            @Override
+            public void onTaskStackChanged() throws RemoteException {
+                synchronized (sLock) {
+                    sTaskStackChangedCalled = true;
+                }
+            }
+        });
+
+        final Context context = getInstrumentation().getContext();
+        context.startActivity(new Intent(context, ResumeWhilePausingActivity.class).addFlags(
+                Intent.FLAG_ACTIVITY_NEW_TASK));
+        UiDevice.getInstance(getInstrumentation()).waitForIdle();
+
+        synchronized (sLock) {
+            assertTrue(sTaskStackChangedCalled);
+        }
+    }
+
+    @Test
+    @Presubmit
     public void testTaskDescriptionChanged() throws Exception {
         final Object[] params = new Object[2];
         final CountDownLatch latch = new CountDownLatch(1);
@@ -617,5 +640,7 @@ public class TaskStackChangedListenerTest {
     // Activity that has {@link android.R.attr#resizeableActivity} attribute set to {@code true}
     public static class ActivityInActivityView extends TestActivity {}
 
+    public static class ResumeWhilePausingActivity extends TestActivity {}
+
     public static class LandscapeActivity extends TestActivity {}
 }