From 3426ed5637e078298cf732376735a7699e180ba3 Mon Sep 17 00:00:00 2001
From: Tony Huang <tonyychuang@google.com>
Date: Thu, 8 Dec 2022 08:12:47 +0000
Subject: [PATCH] Fix null surface crash when switch split

This crash is caused by doble tap sometimes trigger onResizing at
same time. This might be gesture limitation. We should avoid doing
screenshot fade-out animation at such situation because its bounds
didn't change.

Fix: 261809537
Test: manual
Test: pass existing tests
Change-Id: Ida6b6e5f9a19cc2a403bb97d8bc1744c24ad90f7
---
 .../wm/shell/common/split/DividerView.java    |  5 +++++
 .../shell/common/split/SplitDecorManager.java | 22 ++++++++++++-------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/DividerView.java b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/DividerView.java
index 214b304df07c9..c63419851f7f7 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/DividerView.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/DividerView.java
@@ -403,5 +403,10 @@ public class DividerView extends FrameLayout implements View.OnTouchListener {
             }
             return true;
         }
+
+        @Override
+        public boolean onDoubleTapEvent(@NonNull MotionEvent e) {
+            return true;
+        }
     }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitDecorManager.java b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitDecorManager.java
index c836b95ffab8c..a9d3c9f154cde 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitDecorManager.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitDecorManager.java
@@ -74,7 +74,8 @@ public class SplitDecorManager extends WindowlessWindowManager {
 
     private boolean mShown;
     private boolean mIsResizing;
-    private final Rect mBounds = new Rect();
+    private final Rect mOldBounds = new Rect();
+    private final Rect mResizingBounds = new Rect();
     private final Rect mTempRect = new Rect();
     private ValueAnimator mFadeAnimator;
 
@@ -158,6 +159,8 @@ public class SplitDecorManager extends WindowlessWindowManager {
         mResizingIconView = null;
         mIsResizing = false;
         mShown = false;
+        mOldBounds.setEmpty();
+        mResizingBounds.setEmpty();
     }
 
     /** Showing resizing hint. */
@@ -170,13 +173,14 @@ public class SplitDecorManager extends WindowlessWindowManager {
 
         if (!mIsResizing) {
             mIsResizing = true;
-            mBounds.set(newBounds);
+            mOldBounds.set(newBounds);
         }
+        mResizingBounds.set(newBounds);
         mOffsetX = offsetX;
         mOffsetY = offsetY;
 
         final boolean show =
-                newBounds.width() > mBounds.width() || newBounds.height() > mBounds.height();
+                newBounds.width() > mOldBounds.width() || newBounds.height() > mOldBounds.height();
         final boolean update = show != mShown;
         if (update && mFadeAnimator != null && mFadeAnimator.isRunning()) {
             // If we need to animate and animator still running, cancel it before we ensure both
@@ -193,8 +197,8 @@ public class SplitDecorManager extends WindowlessWindowManager {
 
         if (mGapBackgroundLeash == null && !immediately) {
             final boolean isLandscape = newBounds.height() == sideBounds.height();
-            final int left = isLandscape ? mBounds.width() : 0;
-            final int top = isLandscape ? 0 : mBounds.height();
+            final int left = isLandscape ? mOldBounds.width() : 0;
+            final int top = isLandscape ? 0 : mOldBounds.height();
             mGapBackgroundLeash = SurfaceUtils.makeColorLayer(mHostLeash,
                     GAP_BACKGROUND_SURFACE_NAME, mSurfaceSession);
             // Fill up another side bounds area.
@@ -272,6 +276,8 @@ public class SplitDecorManager extends WindowlessWindowManager {
         mIsResizing = false;
         mOffsetX = 0;
         mOffsetY = 0;
+        mOldBounds.setEmpty();
+        mResizingBounds.setEmpty();
         if (mFadeAnimator != null && mFadeAnimator.isRunning()) {
             if (!mShown) {
                 // If fade-out animation is running, just add release callback to it.
@@ -303,8 +309,8 @@ public class SplitDecorManager extends WindowlessWindowManager {
 
     /** Screenshot host leash and attach on it if meet some conditions */
     public void screenshotIfNeeded(SurfaceControl.Transaction t) {
-        if (!mShown && mIsResizing) {
-            mTempRect.set(mBounds);
+        if (!mShown && mIsResizing && !mOldBounds.equals(mResizingBounds)) {
+            mTempRect.set(mOldBounds);
             mTempRect.offsetTo(0, 0);
             mScreenshot = ScreenshotUtils.takeScreenshot(t, mHostLeash, mTempRect,
                     Integer.MAX_VALUE - 1);
@@ -315,7 +321,7 @@ public class SplitDecorManager extends WindowlessWindowManager {
     public void setScreenshotIfNeeded(SurfaceControl screenshot, SurfaceControl.Transaction t) {
         if (screenshot == null || !screenshot.isValid()) return;
 
-        if (!mShown && mIsResizing) {
+        if (!mShown && mIsResizing && !mOldBounds.equals(mResizingBounds)) {
             mScreenshot = screenshot;
             t.reparent(screenshot, mHostLeash);
             t.setLayer(screenshot, Integer.MAX_VALUE - 1);