Play SLEEP transitions if they contain changes

Since queued transitions aren't always cleanly chunked
the way we'd imagine them to be, we may end up with
actual events in the transition info if we happen to
be turning screens on/off/foldingat the same time as doing
things with the device.

In this case, the SLEEP transition would have come first
and the actual changes second, so we should assume these
are changes that need to be played.

Test: atest ShellTransitionTests
Bug: 304713150
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ce1a438ce1fb20fbf031e37677013f93f32c2b5a)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:b121eda4ec93492a690458770155158705e7ffce)
Merged-In: I4bbaa8ad033aaadcb1c0b54889b7c81fb003b001
Change-Id: I4bbaa8ad033aaadcb1c0b54889b7c81fb003b001

3 files changed, 79 insertions, 16 deletions

diff --git a/core/java/android/window/TransitionInfo.java b/core/java/android/window/TransitionInfo.java
index d2a16a3a9212..61f340a856c4 100644
--- a/core/java/android/window/TransitionInfo.java
+++ b/core/java/android/window/TransitionInfo.java
@@ -29,6 +29,7 @@ import static android.view.Display.INVALID_DISPLAY;
 import static android.view.WindowManager.LayoutParams.ROTATION_ANIMATION_UNSPECIFIED;
 import static android.view.WindowManager.TRANSIT_CHANGE;
 import static android.view.WindowManager.TRANSIT_CLOSE;
+import static android.view.WindowManager.TRANSIT_FLAG_KEYGUARD_APPEARING;
 import static android.view.WindowManager.TRANSIT_FLAG_KEYGUARD_GOING_AWAY;
 import static android.view.WindowManager.TRANSIT_NONE;
 import static android.view.WindowManager.TRANSIT_OPEN;
@@ -361,6 +362,15 @@ public final class TransitionInfo implements Parcelable {
     }
 
     /**
+     * Whether this transition contains any changes to the window hierarchy,
+     * including keyguard visibility.
+     */
+    public boolean hasChangesOrSideEffects() {
+        return !mChanges.isEmpty() || isKeyguardGoingAway()
+                || (mFlags & TRANSIT_FLAG_KEYGUARD_APPEARING) != 0;
+    }
+
+    /**
      * Whether this transition includes keyguard going away.
      */
     public boolean isKeyguardGoingAway() {
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/SleepHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/SleepHandler.java
index 87c438a5b37d..ba0ef20c412e 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/SleepHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/SleepHandler.java
@@ -19,13 +19,12 @@ package com.android.wm.shell.transition;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.os.IBinder;
+import android.util.Slog;
 import android.view.SurfaceControl;
 import android.window.TransitionInfo;
 import android.window.TransitionRequestInfo;
 import android.window.WindowContainerTransaction;
 
-import java.util.ArrayList;
-
 /**
  * A Simple handler that tracks SLEEP transitions. We track them specially since we (ab)use these
  * as sentinels for fast-forwarding through animations when the screen is off.
@@ -34,30 +33,25 @@ import java.util.ArrayList;
  * don't register it like a normal handler.
  */
 class SleepHandler implements Transitions.TransitionHandler {
-    final ArrayList<IBinder> mSleepTransitions = new ArrayList<>();
-
     @Override
     public boolean startAnimation(@NonNull IBinder transition, @NonNull TransitionInfo info,
             @NonNull SurfaceControl.Transaction startTransaction,
             @NonNull SurfaceControl.Transaction finishTransaction,
             @NonNull Transitions.TransitionFinishCallback finishCallback) {
-        mSleepTransitions.remove(transition);
-        startTransaction.apply();
-        finishCallback.onTransitionFinished(null);
-        return true;
+        if (info.hasChangesOrSideEffects()) {
+            Slog.e(Transitions.TAG, "Real changes included in a SLEEP transition");
+            return false;
+        } else {
+            startTransaction.apply();
+            finishCallback.onTransitionFinished(null);
+            return true;
+        }
     }
 
     @Override
     @Nullable
     public WindowContainerTransaction handleRequest(@NonNull IBinder transition,
             @NonNull TransitionRequestInfo request) {
-        mSleepTransitions.add(transition);
         return new WindowContainerTransaction();
     }
-
-    @Override
-    public void onTransitionConsumed(@NonNull IBinder transition, boolean aborted,
-            @Nullable SurfaceControl.Transaction finishTransaction) {
-        mSleepTransitions.remove(transition);
-    }
 }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/transition/ShellTransitionTests.java b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/transition/ShellTransitionTests.java
index 99a1ac663286..b32e0d6b4b39 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/transition/ShellTransitionTests.java
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/transition/ShellTransitionTests.java
@@ -1152,7 +1152,7 @@ public class ShellTransitionTests extends ShellTestCase {
     }
 
     @Test
-    public void testEmptyTransitionStillReportsKeyguardGoingAway() {
+    public void testEmptyTransition_withKeyguardGoingAway_plays() {
         Transitions transitions = createTestTransitions();
         transitions.replaceDefaultHandlerForTest(mDefaultHandler);
 
@@ -1171,6 +1171,65 @@ public class ShellTransitionTests extends ShellTestCase {
     }
 
     @Test
+    public void testSleepTransition_withKeyguardGoingAway_plays(){
+        Transitions transitions = createTestTransitions();
+        transitions.replaceDefaultHandlerForTest(mDefaultHandler);
+
+        IBinder transitToken = new Binder();
+        transitions.requestStartTransition(transitToken,
+                new TransitionRequestInfo(TRANSIT_SLEEP, null /* trigger */, null /* remote */));
+
+        // Make a no-op transition
+        TransitionInfo info = new TransitionInfoBuilder(
+                TRANSIT_SLEEP, TRANSIT_FLAG_KEYGUARD_GOING_AWAY, true /* noOp */).build();
+        transitions.onTransitionReady(transitToken, info, new StubTransaction(),
+                new StubTransaction());
+
+        // If keyguard-going-away flag set, then it shouldn't be aborted.
+        assertEquals(1, mDefaultHandler.activeCount());
+    }
+
+    @Test
+    public void testSleepTransition_withChanges_plays(){
+        Transitions transitions = createTestTransitions();
+        transitions.replaceDefaultHandlerForTest(mDefaultHandler);
+
+        IBinder transitToken = new Binder();
+        transitions.requestStartTransition(transitToken,
+                new TransitionRequestInfo(TRANSIT_SLEEP, null /* trigger */, null /* remote */));
+
+        // Make a transition with some changes
+        TransitionInfo info = new TransitionInfoBuilder(TRANSIT_SLEEP)
+                .addChange(TRANSIT_OPEN).build();
+        info.setTrack(0);
+        transitions.onTransitionReady(transitToken, info, new StubTransaction(),
+                new StubTransaction());
+
+        // If there is an actual change, then it shouldn't be aborted.
+        assertEquals(1, mDefaultHandler.activeCount());
+    }
+
+
+    @Test
+    public void testSleepTransition_empty_SyncBySleepHandler() {
+        Transitions transitions = createTestTransitions();
+        transitions.replaceDefaultHandlerForTest(mDefaultHandler);
+
+        IBinder transitToken = new Binder();
+        transitions.requestStartTransition(transitToken,
+                new TransitionRequestInfo(TRANSIT_SLEEP, null /* trigger */, null /* remote */));
+
+        // Make a no-op transition
+        TransitionInfo info = new TransitionInfoBuilder(
+                TRANSIT_SLEEP, 0x0, true /* noOp */).build();
+        transitions.onTransitionReady(transitToken, info, new StubTransaction(),
+                new StubTransaction());
+
+        // If there is nothing to actually play, it should not be offered to handlers.
+        assertEquals(0, mDefaultHandler.activeCount());
+    }
+
+    @Test
     public void testMultipleTracks() {
         Transitions transitions = createTestTransitions();
         transitions.replaceDefaultHandlerForTest(mDefaultHandler);