From c2bae89e368945aa89cec484bc45cc297699ba29 Mon Sep 17 00:00:00 2001
From: Evan Laird <evanlaird@google.com>
Date: Wed, 1 Jul 2020 20:33:27 -0400
Subject: [PATCH] Cache Display.Mode so we can ignore refresh rate changes

DisplayCutoutView calls #update() when `onDisplayChanged` is called, but
if that were to be called _only_ because the refresh rate changes, then
we redraw the displaycutoutview (with no meaningful changes) and this
causes the display to change refresh rate again, starting the loop over.

Fixes: 155155363
Test: manual
Change-Id: Ic885cf24a9f4cc45970a3388653789abb3f592bb
---
 .../android/systemui/ScreenDecorations.java   | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/packages/SystemUI/src/com/android/systemui/ScreenDecorations.java b/packages/SystemUI/src/com/android/systemui/ScreenDecorations.java
index 6c06553a84a6c..ad11d71eb132a 100644
--- a/packages/SystemUI/src/com/android/systemui/ScreenDecorations.java
+++ b/packages/SystemUI/src/com/android/systemui/ScreenDecorations.java
@@ -62,6 +62,7 @@ import android.os.UserHandle;
 import android.provider.Settings.Secure;
 import android.util.DisplayMetrics;
 import android.util.Log;
+import android.view.Display;
 import android.view.DisplayCutout;
 import android.view.DisplayCutout.BoundsPosition;
 import android.view.DisplayInfo;
@@ -820,6 +821,7 @@ public class ScreenDecorations extends SystemUI implements Tunable {
 
         private static final float HIDDEN_CAMERA_PROTECTION_SCALE = 0.5f;
 
+        private Display.Mode mDisplayMode = null;
         private final DisplayInfo mInfo = new DisplayInfo();
         private final Paint mPaint = new Paint();
         private final List<Rect> mBounds = new ArrayList();
@@ -904,11 +906,33 @@ public class ScreenDecorations extends SystemUI implements Tunable {
 
         @Override
         public void onDisplayChanged(int displayId) {
+            Display.Mode oldMode = mDisplayMode;
+            mDisplayMode = getDisplay().getMode();
+
+            // Display mode hasn't meaningfully changed, we can ignore it
+            if (!modeChanged(oldMode, mDisplayMode)) {
+                return;
+            }
+
             if (displayId == getDisplay().getDisplayId()) {
                 update();
             }
         }
 
+        private boolean modeChanged(Display.Mode oldMode, Display.Mode newMode) {
+            if (oldMode == null) {
+                return true;
+            }
+
+            boolean changed = false;
+            changed |= oldMode.getPhysicalHeight() != newMode.getPhysicalHeight();
+            changed |= oldMode.getPhysicalWidth() != newMode.getPhysicalWidth();
+            // We purposely ignore refresh rate and id changes here, because we don't need to
+            // invalidate for those, and they can trigger the refresh rate to increase
+
+            return changed;
+        }
+
         public void setRotation(int rotation) {
             mRotation = rotation;
             update();