From f4372d914e5960ded577e9a3e8194294d708bf35 Mon Sep 17 00:00:00 2001
From: gaochong <gaochong@xiaomi.com>
Date: Wed, 14 Jun 2017 21:51:11 +0800
Subject: [PATCH] Fix Screen Magnification recursive draw

When invoke the method View#setLayoutParams(), ViewRootImpl
will run method ViewRootImpl#performTraversals(). And
OnGlobalLayoutListener#onGlobalLayout() will be invoked.
When the method View#setLayoutParams() is invoked in
OnGlobalLayoutListener#onGlobalLayout(), there will be recursive
call. The view will be draw on and on. This situation happen in
Screen Magnification. It should remove the listener after
work completion.

Bug: https://issuetracker.google.com/issues/62613000

Test: use systrace when enter Screen Magnification,and view the
"traversal" times.

Change-Id: I01b1fcccb8b915ec436fb95f1d30c8ec0c0de0a9
Signed-off-by: gaochong <gaochong@xiaomi.com>
---
 .../ToggleScreenMagnificationPreferenceFragment.java            | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java b/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
index e6a8c1e829c..669d51eaa07 100644
--- a/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
+++ b/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
@@ -98,6 +98,8 @@ public class ToggleScreenMagnificationPreferenceFragment extends ToggleFeaturePr
                     videoView.setLayoutParams(videoLp);
                     videoView.invalidate();
                     videoView.start();
+                    mVideoBackgroundView.getViewTreeObserver()
+                            .removeOnGlobalLayoutListener(mLayoutListener);
                 }
             };