From 4f3deb875f42f9c196ff183446bbfa7f6ef56c8e Mon Sep 17 00:00:00 2001
From: Chris Li <lihongyu@google.com>
Date: Thu, 9 Feb 2023 17:09:34 +0800
Subject: [PATCH] Set starting frame to startTransaction for ActivityEmbedding
 transition

Before, the first frame is set later when the animation starts, which
can have a flicker between the startTransaction.apply().

Fix: 268309880
Test: deflaky the OpenActivityEmbeddingSecondaryToSplitTest
Change-Id: Iedeb91295ec365e9a82f5b06539d07745ff6d699
---
 .../ActivityEmbeddingAnimationAdapter.java    | 21 +++++++++----------
 .../ActivityEmbeddingAnimationRunner.java     | 12 +++++++++++
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationAdapter.java b/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationAdapter.java
index 00b9fcede4cad..579f7aae9321a 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationAdapter.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationAdapter.java
@@ -22,7 +22,6 @@ import static android.graphics.Matrix.MTRANS_Y;
 import android.annotation.CallSuper;
 import android.graphics.Point;
 import android.graphics.Rect;
-import android.view.Choreographer;
 import android.view.SurfaceControl;
 import android.view.animation.Animation;
 import android.view.animation.Transformation;
@@ -71,7 +70,6 @@ class ActivityEmbeddingAnimationAdapter {
     final float[] mVecs = new float[4];
     @NonNull
     final Rect mRect = new Rect();
-    private boolean mIsFirstFrame = true;
     private int mOverrideLayer = LAYER_NO_OVERRIDE;
 
     ActivityEmbeddingAnimationAdapter(@NonNull Animation animation,
@@ -117,20 +115,21 @@ class ActivityEmbeddingAnimationAdapter {
         mOverrideLayer = layer;
     }
 
+    /** Called to prepare for the starting state. */
+    final void prepareForFirstFrame(@NonNull SurfaceControl.Transaction startTransaction) {
+        startTransaction.show(mLeash);
+        if (mOverrideLayer != LAYER_NO_OVERRIDE) {
+            startTransaction.setLayer(mLeash, mOverrideLayer);
+        }
+        mAnimation.getTransformationAt(0, mTransformation);
+        onAnimationUpdateInner(startTransaction);
+    }
+
     /** Called on frame update. */
     final void onAnimationUpdate(@NonNull SurfaceControl.Transaction t, long currentPlayTime) {
-        if (mIsFirstFrame) {
-            t.show(mLeash);
-            if (mOverrideLayer != LAYER_NO_OVERRIDE) {
-                t.setLayer(mLeash, mOverrideLayer);
-            }
-            mIsFirstFrame = false;
-        }
-
         // Extract the transformation to the current time.
         mAnimation.getTransformation(Math.min(currentPlayTime, mAnimation.getDuration()),
                 mTransformation);
-        t.setFrameTimelineVsync(Choreographer.getInstance().getVsyncId());
         onAnimationUpdateInner(t);
     }
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationRunner.java b/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationRunner.java
index 164d2f149931f..fe3c4ea3fee9f 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationRunner.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/activityembedding/ActivityEmbeddingAnimationRunner.java
@@ -32,6 +32,7 @@ import android.graphics.Rect;
 import android.os.IBinder;
 import android.util.ArraySet;
 import android.util.Log;
+import android.view.Choreographer;
 import android.view.SurfaceControl;
 import android.view.animation.Animation;
 import android.window.TransitionInfo;
@@ -130,11 +131,13 @@ class ActivityEmbeddingAnimationRunner {
             animator.addUpdateListener((anim) -> {
                 // Update all adapters in the same transaction.
                 final SurfaceControl.Transaction t = new SurfaceControl.Transaction();
+                t.setFrameTimelineVsync(Choreographer.getInstance().getVsyncId());
                 for (ActivityEmbeddingAnimationAdapter adapter : adapters) {
                     adapter.onAnimationUpdate(t, animator.getCurrentPlayTime());
                 }
                 t.apply();
             });
+            prepareForFirstFrame(startTransaction, adapters);
         }
         animator.setDuration(duration);
         animator.addListener(new Animator.AnimatorListener() {
@@ -248,6 +251,15 @@ class ActivityEmbeddingAnimationRunner {
         return adapters;
     }
 
+    /** Sets the first frame to the {@code startTransaction} to avoid any flicker on start. */
+    private void prepareForFirstFrame(@NonNull SurfaceControl.Transaction startTransaction,
+            @NonNull List<ActivityEmbeddingAnimationAdapter> adapters) {
+        startTransaction.setFrameTimelineVsync(Choreographer.getInstance().getVsyncId());
+        for (ActivityEmbeddingAnimationAdapter adapter : adapters) {
+            adapter.prepareForFirstFrame(startTransaction);
+        }
+    }
+
     /** Adds edge extension to the surfaces that have such an animation property. */
     private void addEdgeExtensionIfNeeded(@NonNull SurfaceControl.Transaction startTransaction,
             @NonNull SurfaceControl.Transaction finishTransaction,