From b1a7a586015ff7789e53797a4a91bf8d4bc33958 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Wed, 17 Aug 2022 21:48:19 +0800
Subject: [PATCH] Crop windowing layer for shell rotation animation

This aligns the behavior as legacy rotation animation in commit db7097e.
Note that the crop will be cleared in finishTransaction set from core's
Transition#buildFinishTransaction.

Also clean some fields a bit.

Bug: 242664636
Test: Enable launcher rotation. Set animation scale to 10x.
      Rotate display and observe that the wallpaper does not exceed
      the area of previous display size.
Change-Id: Ie2144f7c19663b573167de819dde01cc9eca7ad4
---
 .../transition/ScreenRotationAnimation.java   | 27 ++++++-------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
index 45b69f17a861d..6388ca13090e7 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
@@ -86,8 +86,6 @@ class ScreenRotationAnimation {
     private final float[] mTmpFloats = new float[9];
     /** The leash of the changing window container. */
     private final SurfaceControl mSurfaceControl;
-    private final Rect mStartBounds = new Rect();
-    private final Rect mEndBounds = new Rect();
 
     private final int mAnimHint;
     private final int mStartWidth;
@@ -105,8 +103,7 @@ class ScreenRotationAnimation {
      */
     private SurfaceControl mBackColorSurface;
     /** The leash using to animate screenshot layer. */
-    private SurfaceControl mAnimLeash;
-    private Transaction mTransaction;
+    private final SurfaceControl mAnimLeash;
 
     // The current active animation to move from the old to the new rotated
     // state.  Which animation is run here will depend on the old and new
@@ -134,9 +131,6 @@ class ScreenRotationAnimation {
         mStartRotation = change.getStartRotation();
         mEndRotation = change.getEndRotation();
 
-        mStartBounds.set(change.getStartAbsBounds());
-        mEndBounds.set(change.getEndAbsBounds());
-
         mAnimLeash = new SurfaceControl.Builder(session)
                 .setParent(rootLeash)
                 .setEffectLayer()
@@ -169,6 +163,8 @@ class ScreenRotationAnimation {
 
             t.setLayer(mAnimLeash, SCREEN_FREEZE_LAYER_BASE);
             t.show(mAnimLeash);
+            // Crop the real content in case it contains a larger child layer, e.g. wallpaper.
+            t.setCrop(mSurfaceControl, new Rect(0, 0, mEndWidth, mEndHeight));
 
             final ColorSpace colorSpace = screenshotBuffer.getColorSpace();
             final HardwareBuffer hardwareBuffer = screenshotBuffer.getHardwareBuffer();
@@ -306,7 +302,6 @@ class ScreenRotationAnimation {
         mRotateEnterAnimation.restrictDuration(MAX_ANIMATION_DURATION);
         mRotateEnterAnimation.scaleCurrentDuration(animationScale);
 
-        mTransaction = mTransactionPool.acquire();
         if (customRotate) {
             mRotateAlphaAnimation.initialize(mEndWidth, mEndHeight, mStartWidth, mStartHeight);
             mRotateAlphaAnimation.restrictDuration(MAX_ANIMATION_DURATION);
@@ -386,22 +381,16 @@ class ScreenRotationAnimation {
     }
 
     public void kill() {
-        Transaction t = mTransaction != null ? mTransaction : mTransactionPool.acquire();
+        final Transaction t = mTransactionPool.acquire();
         if (mAnimLeash.isValid()) {
             t.remove(mAnimLeash);
         }
 
-        if (mScreenshotLayer != null) {
-            if (mScreenshotLayer.isValid()) {
-                t.remove(mScreenshotLayer);
-            }
-            mScreenshotLayer = null;
+        if (mScreenshotLayer != null && mScreenshotLayer.isValid()) {
+            t.remove(mScreenshotLayer);
         }
-        if (mBackColorSurface != null) {
-            if (mBackColorSurface.isValid()) {
-                t.remove(mBackColorSurface);
-            }
-            mBackColorSurface = null;
+        if (mBackColorSurface != null && mBackColorSurface.isValid()) {
+            t.remove(mBackColorSurface);
         }
         t.apply();
         mTransactionPool.release(t);