From 389beec68d09883112ee5ef88f0b2fa2aa369824 Mon Sep 17 00:00:00 2001
From: Adrian Roos <roosa@google.com>
Date: Tue, 12 May 2015 13:33:25 -0700
Subject: [PATCH] Only dispatch systemUiVisibility when it actually changes

Bug: 19000727
Change-Id: I9302746281188186d18256d45fee681bd2ab50d5
---
 .../android/systemui/statusbar/phone/PhoneStatusBar.java  | 8 +++++++-
 .../java/com/android/server/wm/WindowManagerService.java  | 7 +++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
index 8ccd222b50c45..df0a95915b6c1 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
@@ -312,6 +312,9 @@ public class PhoneStatusBar extends BaseStatusBar implements DemoMode,
     // tracking calls to View.setSystemUiVisibility()
     int mSystemUiVisibility = View.SYSTEM_UI_FLAG_VISIBLE;
 
+    // last value sent to window manager
+    private int mLastDispatchedSystemUiVisibility = ~View.SYSTEM_UI_FLAG_VISIBLE;
+
     DisplayMetrics mDisplayMetrics = new DisplayMetrics();
 
     // XXX: gesture research
@@ -2481,7 +2484,10 @@ public class PhoneStatusBar extends BaseStatusBar implements DemoMode,
 
     private void notifyUiVisibilityChanged(int vis) {
         try {
-            mWindowManagerService.statusBarVisibilityChanged(vis);
+            if (mLastDispatchedSystemUiVisibility != vis) {
+                mWindowManagerService.statusBarVisibilityChanged(vis);
+                mLastDispatchedSystemUiVisibility = vis;
+            }
         } catch (RemoteException ex) {
         }
     }
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 06d3b223fd975..57bad514da4a6 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -512,7 +512,10 @@ public class WindowManagerService extends IWindowManager.Stub
 
     int mLayoutSeq = 0;
 
+    // Last systemUiVisibility we received from status bar.
     int mLastStatusBarVisibility = 0;
+    // Last systemUiVisibility we dispatched to windows.
+    int mLastDispatchedSystemUiVisibility = 0;
 
     // State while inside of layoutAndPlaceSurfacesLocked().
     boolean mFocusMayChange;
@@ -10955,6 +10958,10 @@ public class WindowManagerService extends IWindowManager.Stub
 
     // TOOD(multidisplay): StatusBar on multiple screens?
     void updateStatusBarVisibilityLocked(int visibility) {
+        if (mLastDispatchedSystemUiVisibility == visibility) {
+            return;
+        }
+        mLastDispatchedSystemUiVisibility = visibility;
         mInputManager.setSystemUiVisibility(visibility);
         final WindowList windows = getDefaultWindowListLocked();
         final int N = windows.size();