From 3ae8aab87f8646908173b12de2eadc2dc6e266b1 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Tue, 16 Jun 2020 18:56:17 +0800
Subject: [PATCH] Finish fixed rotation while the task has done transition

Assume an activity A is started in portrait and it starts another
landscape activity B immediately in the same task. If fixed rotation
applies for this case, the starting window will transfer across
different orientations that may look flickering. And because the
transformed activity is the B, the transition finished event of A
cannot match B that causes the display stays in old orientation.

This change makes the case use normal rotation animation to avoid the
flickering, and still handles the case that the transition is done
but the notified record is the first activity to avoid other similar
cases to miss the orientation update.

Fixes: 158112625
Test: DisplayContentTests#testFinishFixedRotationNoAppTransitioningTask

Change-Id: I559b0881463e379c17e35b7cfd96948feb36bf4b
---
 .../com/android/server/wm/DisplayContent.java | 39 ++++++++++++++-----
 .../server/wm/DisplayContentTests.java        | 25 +++++++++++-
 2 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index fb602573e31b2..ea574d5908ff4 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1463,9 +1463,10 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
             return true;
         }
         if (checkOpening) {
-            if (!mAppTransition.isTransitionSet() && !mOpeningApps.contains(r)) {
+            if (!mAppTransition.isTransitionSet() || !mOpeningApps.contains(r)) {
                 // Apply normal rotation animation in case of the activity set different requested
-                // orientation without activity switch.
+                // orientation without activity switch, or the transition is unset due to starting
+                // window was transferred ({@link #mSkipAppTransitionAnimation}).
                 return false;
             }
         } else if (r != topRunningActivity()) {
@@ -5673,16 +5674,36 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
             if (r == null || r == mAnimatingRecents) {
                 return;
             }
-            if (mFixedRotationLaunchingApp != null
-                    && mFixedRotationLaunchingApp.hasFixedRotationTransform(r)) {
-                // Waiting until all of the associated activities have done animation, or the
-                // orientation would be updated too early and cause flickers.
-                if (!mFixedRotationLaunchingApp.hasAnimatingFixedRotationTransition()) {
-                    continueUpdateOrientationForDiffOrienLaunchingApp();
+            if (mFixedRotationLaunchingApp == null) {
+                // In most cases this is a no-op if the activity doesn't have fixed rotation.
+                // Otherwise it could be from finishing recents animation while the display has
+                // different orientation.
+                r.finishFixedRotationTransform();
+                return;
+            }
+            if (mFixedRotationLaunchingApp.hasFixedRotationTransform(r)) {
+                if (mFixedRotationLaunchingApp.hasAnimatingFixedRotationTransition()) {
+                    // Waiting until all of the associated activities have done animation, or the
+                    // orientation would be updated too early and cause flickering.
+                    return;
                 }
             } else {
-                r.finishFixedRotationTransform();
+                // Handle a corner case that the task of {@link #mFixedRotationLaunchingApp} is no
+                // longer animating but the corresponding transition finished event won't notify.
+                // E.g. activity A transferred starting window to B, only A will receive transition
+                // finished event. A doesn't have fixed rotation but B is the rotated launching app.
+                final Task task = r.getTask();
+                if (task == null || task != mFixedRotationLaunchingApp.getTask()) {
+                    // Different tasks won't be in one activity transition animation.
+                    return;
+                }
+                if (task.isAppTransitioning()) {
+                    return;
+                    // Continue to update orientation because the transition of the top rotated
+                    // launching activity is done.
+                }
             }
+            continueUpdateOrientationForDiffOrienLaunchingApp();
         }
 
         @Override
diff --git a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
index d3f677ced3294..bf1ff7b175891 100644
--- a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
@@ -1134,8 +1134,6 @@ public class DisplayContentTests extends WindowTestsBase {
         // Launch another activity before the transition is finished.
         final ActivityRecord app2 = new ActivityTestsBase.StackBuilder(mWm.mRoot)
                 .setDisplay(mDisplayContent).build().getTopMostActivity();
-        mDisplayContent.prepareAppTransition(WindowManager.TRANSIT_ACTIVITY_OPEN,
-                false /* alwaysKeepCurrent */);
         mDisplayContent.mOpeningApps.add(app2);
         app2.setRequestedOrientation(newOrientation);
 
@@ -1161,6 +1159,29 @@ public class DisplayContentTests extends WindowTestsBase {
         assertNull(mDisplayContent.getFixedRotationAnimationController());
     }
 
+    @Test
+    public void testFinishFixedRotationNoAppTransitioningTask() {
+        final ActivityRecord app = mAppWindow.mActivityRecord;
+        final Task task = app.getTask();
+        final ActivityRecord app2 = new ActivityTestsBase.ActivityBuilder(mWm.mAtmService)
+                .setTask(task).build();
+        mDisplayContent.setFixedRotationLaunchingApp(app2, (mDisplayContent.getRotation() + 1) % 4);
+        doReturn(true).when(task).isAppTransitioning();
+        // If the task is animating transition, this should be no-op.
+        mDisplayContent.mFixedRotationTransitionListener.onAppTransitionFinishedLocked(app.token);
+
+        assertTrue(app2.hasFixedRotationTransform());
+        assertTrue(mDisplayContent.hasTopFixedRotationLaunchingApp());
+
+        doReturn(false).when(task).isAppTransitioning();
+        // Although this notifies app instead of app2 that uses the fixed rotation, app2 should
+        // still finish the transform because there is no more transition event.
+        mDisplayContent.mFixedRotationTransitionListener.onAppTransitionFinishedLocked(app.token);
+
+        assertFalse(app2.hasFixedRotationTransform());
+        assertFalse(mDisplayContent.hasTopFixedRotationLaunchingApp());
+    }
+
     @Test
     public void testRotateSeamlesslyWithFixedRotation() {
         final DisplayRotation displayRotation = mDisplayContent.getDisplayRotation();