Calculate the correct surface layers for finishTransaction
We normally prevent assignLayers from touching surface z-order
during transition animations. However, this causes a problem
when multiple transitions happen in quick succession (eg. during
CTS tests) because final surface z-order may not be updated.
To fix this, allow assignLayers to set layers into the
finishTransaction. This is applied by shell and is expected
to represent the "z-order at the end of animation", so we
obviously should allow it to get the fully calculated layers.
Bug: 237545923
Test: atest PinnedStackTests
Change-Id: Ifb8c339fcd9fce7d3457dae806b6d3b186ea5d5c
diff --git a/services/core/java/com/android/server/wm/Transition.java b/services/core/java/com/android/server/wm/Transition.java
index 09f6110..c455ac1 100644
--- a/services/core/java/com/android/server/wm/Transition.java
+++ b/services/core/java/com/android/server/wm/Transition.java
@@ -533,9 +533,14 @@
}
// Need to update layers on involved displays since they were all paused while
// the animation played. This puts the layers back into the correct order.
- for (int i = displays.size() - 1; i >= 0; --i) {
- if (displays.valueAt(i) == null) continue;
- displays.valueAt(i).assignChildLayers(t);
+ mController.mBuildingFinishLayers = true;
+ try {
+ for (int i = displays.size() - 1; i >= 0; --i) {
+ if (displays.valueAt(i) == null) continue;
+ displays.valueAt(i).assignChildLayers(t);
+ }
+ } finally {
+ mController.mBuildingFinishLayers = false;
}
if (rootLeash.isValid()) {
t.reparent(rootLeash, null);
diff --git a/services/core/java/com/android/server/wm/TransitionController.java b/services/core/java/com/android/server/wm/TransitionController.java
index dbc2c5f..88572a9 100644
--- a/services/core/java/com/android/server/wm/TransitionController.java
+++ b/services/core/java/com/android/server/wm/TransitionController.java
@@ -100,6 +100,14 @@
// TODO(b/188595497): remove when not needed.
final StatusBarManagerInternal mStatusBar;
+ /**
+ * `true` when building surface layer order for the finish transaction. We want to prevent
+ * wm from touching z-order of surfaces during transitions, but we still need to be able to
+ * calculate the layers for the finishTransaction. So, when assigning layers into the finish
+ * transaction, set this to true so that the {@link canAssignLayers} will allow it.
+ */
+ boolean mBuildingFinishLayers = false;
+
TransitionController(ActivityTaskManagerService atm,
TaskSnapshotController taskSnapshotController,
TransitionTracer transitionTracer) {
@@ -309,6 +317,15 @@
return false;
}
+ /**
+ * Whether WM can assign layers to window surfaces at this time. This is usually false while
+ * playing, but can be "opened-up" for certain transition operations like calculating layers
+ * for finishTransaction.
+ */
+ boolean canAssignLayers() {
+ return mBuildingFinishLayers || !isPlaying();
+ }
+
@WindowConfiguration.WindowingMode
int getWindowingModeAtStart(@NonNull WindowContainer wc) {
if (mCollectingTransition == null) return wc.getWindowingMode();
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index 19b3384..8a32df6 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -2473,7 +2473,7 @@
void assignLayer(Transaction t, int layer) {
// Don't assign layers while a transition animation is playing
// TODO(b/173528115): establish robust best-practices around z-order fighting.
- if (mTransitionController.isPlaying()) return;
+ if (!mTransitionController.canAssignLayers()) return;
final boolean changed = layer != mLastLayer || mLastRelativeToLayer != null;
if (mSurfaceControl != null && changed) {
setLayer(t, layer);
