Wait with reparenting back until all app animations are done

An activity A that has a shorter animation that is above another
activity B with a longer animation in the same task, the animation
layer would put the B on top of A, but from the hierarchy, A needs
to be on top of B. Thus, we defer reparenting A to the original
hierarchy such that it stays on top of B until B finishes
animating.

Test: Above scenario
Test: AnimatingAppWindowTokenRegistryTest
Fixes: 75246892
Change-Id: I73796376c1cbeb8327262a304911ce2abfbbb0b6
diff --git a/services/tests/servicestests/src/com/android/server/wm/AnimatingAppWindowTokenRegistryTest.java b/services/tests/servicestests/src/com/android/server/wm/AnimatingAppWindowTokenRegistryTest.java
new file mode 100644
index 0000000..8b78f10
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/wm/AnimatingAppWindowTokenRegistryTest.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.wm;
+
+import static android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD;
+import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
+import static junit.framework.Assert.assertFalse;
+import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+import android.platform.test.annotations.Presubmit;
+import android.support.test.filters.FlakyTest;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import com.android.server.wm.SurfaceAnimator.OnAnimationFinishedCallback;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/**
+ * Tests for the {@link TaskStack} class.
+ *
+ * Build/Install/Run:
+ *  atest FrameworksServicesTests:com.android.server.wm.AnimatingAppWindowTokenRegistryTest
+ */
+@SmallTest
+@Presubmit
+@FlakyTest(detail = "Promote once confirmed non-flaky")
+@RunWith(AndroidJUnit4.class)
+public class AnimatingAppWindowTokenRegistryTest extends WindowTestsBase {
+
+    @Mock
+    AnimationAdapter mAdapter;
+
+    @Mock
+    Runnable mMockEndDeferFinishCallback1;
+    @Mock
+    Runnable mMockEndDeferFinishCallback2;
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Test
+    public void testDeferring() throws Exception {
+        final AppWindowToken window1 = createAppWindowToken(mDisplayContent,
+                WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD);
+        final AppWindowToken window2 = createAppWindow(window1.getTask(), ACTIVITY_TYPE_STANDARD,
+                "window2").mAppToken;
+        final AnimatingAppWindowTokenRegistry registry =
+                window1.getStack().getAnimatingAppWindowTokenRegistry();
+
+        window1.startAnimation(window1.getPendingTransaction(), mAdapter, false /* hidden */);
+        window2.startAnimation(window1.getPendingTransaction(), mAdapter, false /* hidden */);
+        assertTrue(window1.isSelfAnimating());
+        assertTrue(window2.isSelfAnimating());
+
+        // Make sure that first animation finish is deferred, second one is not deferred, and first
+        // one gets cancelled.
+        assertTrue(registry.notifyAboutToFinish(window1, mMockEndDeferFinishCallback1));
+        assertFalse(registry.notifyAboutToFinish(window2, mMockEndDeferFinishCallback2));
+        verify(mMockEndDeferFinishCallback1).run();
+        verifyZeroInteractions(mMockEndDeferFinishCallback2);
+    }
+}