From 749de2e17a16ba881b21924b847ce4b441ee34f5 Mon Sep 17 00:00:00 2001
From: Yurii Zubrytskyi <zyy@google.com>
Date: Tue, 11 Oct 2022 15:47:02 -0700
Subject: [PATCH] [sysui] Use weak reference for the listener in
 NavigationBarTransitions

The listener is the only thing keeping objects alive after
switching dark theme, bringing the number of Resources.Theme
objects to thousands.

Bug: 242005877
Test: manual, 10k theme switches to verify there's fewer active
      theme objects
Change-Id: I59ff27dacd4bcad933341886c249074cf7df6dc9
(cherry picked from commit 0776b3b410c86dd8f739097d3c53bc3ec7d5679a)
---
 .../NavigationBarTransitions.java             | 27 ++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/navigationbar/NavigationBarTransitions.java b/packages/SystemUI/src/com/android/systemui/navigationbar/NavigationBarTransitions.java
index a4de9ffbfa514..20b50325f65f2 100644
--- a/packages/SystemUI/src/com/android/systemui/navigationbar/NavigationBarTransitions.java
+++ b/packages/SystemUI/src/com/android/systemui/navigationbar/NavigationBarTransitions.java
@@ -36,6 +36,7 @@ import com.android.systemui.statusbar.phone.BarTransitions;
 import com.android.systemui.statusbar.phone.LightBarTransitionsController;
 
 import java.io.PrintWriter;
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -76,15 +77,27 @@ public final class NavigationBarTransitions extends BarTransitions implements
     private List<DarkIntensityListener> mDarkIntensityListeners;
 
     private final Handler mHandler = Handler.getMain();
-    private final IWallpaperVisibilityListener mWallpaperVisibilityListener =
-            new IWallpaperVisibilityListener.Stub() {
+
+    static final class WallpaperVisibilityListener extends IWallpaperVisibilityListener.Stub {
+        private final WeakReference<NavigationBarTransitions> mSelf;
+
+        WallpaperVisibilityListener(NavigationBarTransitions self) {
+            mSelf = new WeakReference<>(self);
+        }
+
         @Override
         public void onWallpaperVisibilityChanged(boolean newVisibility,
-        int displayId) throws RemoteException {
-            mWallpaperVisible = newVisibility;
-            mHandler.post(() -> applyLightsOut(true, false));
+                int displayId) throws RemoteException {
+            NavigationBarTransitions self = mSelf.get();
+            if (self == null) {
+                return;
+            }
+            self.mWallpaperVisible = newVisibility;
+            self.mHandler.post(() -> self.applyLightsOut(true, false));
         }
-    };
+    }
+
+    private final IWallpaperVisibilityListener mWallpaperVisibilityListener;
 
     @Inject
     public NavigationBarTransitions(
@@ -93,6 +106,7 @@ public final class NavigationBarTransitions extends BarTransitions implements
             LightBarTransitionsController.Factory lightBarTransitionsControllerFactory,
             DisplayTracker displayTracker) {
         super(view, R.drawable.nav_background);
+
         mView = view;
         mWindowManagerService = windowManagerService;
         mLightTransitionsController = lightBarTransitionsControllerFactory.create(this);
@@ -101,6 +115,7 @@ public final class NavigationBarTransitions extends BarTransitions implements
                 .getBoolean(R.bool.config_navigation_bar_enable_auto_dim_no_visible_wallpaper);
         mDarkIntensityListeners = new ArrayList();
 
+        mWallpaperVisibilityListener = new WallpaperVisibilityListener(this);
         try {
             mWallpaperVisible = mWindowManagerService.registerWallpaperVisibilityListener(
                     mWallpaperVisibilityListener, mDisplayTracker.getDefaultDisplayId());