Explicitly release references to the controller

- This is a workaround for lingering phantom references to binder
  stubs

Flag: EXEMPT bugfix
Bug: 332339792
Test: Presubmit
Change-Id: I3e790f627d434760e87be1dc6c8643d03fceb400

quickstep/src/com/android/launcher3/statehandlers/DesktopVisibilityController.java

@@ -26,6 +26,7 @@ import android.os.SystemProperties;
 import android.util.Log;
 import android.view.View;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import com.android.launcher3.Launcher;
@@ -39,6 +40,7 @@ import com.android.wm.shell.desktopmode.IDesktopTaskListener;
 
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.Executor;
 
 /**
  * Controls the visibility of the workspace and the resumed / paused state when desktop mode
@@ -57,7 +59,7 @@ public class DesktopVisibilityController {
     private boolean mGestureInProgress;
 
     @Nullable
-    private IDesktopTaskListener mDesktopTaskListener;
+    private DesktopTaskListenerImpl mDesktopTaskListener;
 
     public DesktopVisibilityController(Launcher launcher) {
         mLauncher = launcher;
@@ -67,24 +69,7 @@ public class DesktopVisibilityController {
      * Register a listener with System UI to receive updates about desktop tasks state
      */
     public void registerSystemUiListener() {
-        mDesktopTaskListener = new IDesktopTaskListener.Stub() {
-            @Override
-            public void onTasksVisibilityChanged(int displayId, int visibleTasksCount) {
-                MAIN_EXECUTOR.execute(() -> {
-                    if (displayId == mLauncher.getDisplayId()) {
-                        if (DEBUG) {
-                            Log.d(TAG, "desktop visible tasks count changed=" + visibleTasksCount);
-                        }
-                        setVisibleDesktopTasksCount(visibleTasksCount);
-                    }
-                });
-            }
-
-            @Override
-            public void onStashedChanged(int displayId, boolean stashed) {
-              Log.w(TAG, "IDesktopTaskListener: onStashedChanged is deprecated");
-            }
-        };
+        mDesktopTaskListener = new DesktopTaskListenerImpl(this, mLauncher.getDisplayId());
         SystemUiProxy.INSTANCE.get(mLauncher).setDesktopTaskListener(mDesktopTaskListener);
     }
 
@@ -93,6 +78,7 @@ public class DesktopVisibilityController {
      */
     public void unregisterSystemUiListener() {
         SystemUiProxy.INSTANCE.get(mLauncher).setDesktopTaskListener(null);
+        mDesktopTaskListener.release();
         mDesktopTaskListener = null;
     }
 
@@ -356,4 +342,43 @@ public class DesktopVisibilityController {
          */
         void onDesktopVisibilityChanged(boolean visible);
     }
+
+    /**
+     * Wrapper for the IDesktopTaskListener stub to prevent lingering references to the launcher
+     * activity via the controller.
+     */
+    private static class DesktopTaskListenerImpl extends IDesktopTaskListener.Stub {
+
+        private DesktopVisibilityController mController;
+        private final int mDisplayId;
+
+        DesktopTaskListenerImpl(@NonNull DesktopVisibilityController controller, int displayId) {
+            mController = controller;
+            mDisplayId = displayId;
+        }
+
+        /**
+         * Clears any references to the controller.
+         */
+        void release() {
+            mController = null;
+        }
+
+        @Override
+        public void onTasksVisibilityChanged(int displayId, int visibleTasksCount) {
+            MAIN_EXECUTOR.execute(() -> {
+                if (mController != null && displayId == mDisplayId) {
+                    if (DEBUG) {
+                        Log.d(TAG, "desktop visible tasks count changed=" + visibleTasksCount);
+                    }
+                    mController.setVisibleDesktopTasksCount(visibleTasksCount);
+                }
+            });
+        }
+
+        @Override
+        public void onStashedChanged(int displayId, boolean stashed) {
+            Log.w(TAG, "IDesktopTaskListener: onStashedChanged is deprecated");
+        }
+    }
 }

quickstep/src/com/android/quickstep/util/SplitSelectStateController.java

@@ -961,7 +961,7 @@ public class SplitSelectStateController {
         private final int mSplitPlaceholderSize;
         private final int mSplitPlaceholderInset;
         private ActivityManager.RunningTaskInfo mTaskInfo;
-        private ISplitSelectListener mSplitSelectListener;
+        private DesktopSplitSelectListenerImpl mSplitSelectListener;
         private Drawable mAppIcon;
 
         public SplitFromDesktopController(QuickstepLauncher launcher,
@@ -972,21 +972,14 @@ public class SplitSelectStateController {
                     R.dimen.split_placeholder_size);
             mSplitPlaceholderInset = mLauncher.getResources().getDimensionPixelSize(
                     R.dimen.split_placeholder_inset);
-            mSplitSelectListener = new ISplitSelectListener.Stub() {
-                @Override
-                public boolean onRequestSplitSelect(ActivityManager.RunningTaskInfo taskInfo,
-                        int splitPosition, Rect taskBounds) {
-                    MAIN_EXECUTOR.execute(() -> enterSplitSelect(taskInfo, splitPosition,
-                            taskBounds));
-                    return true;
-                }
-            };
+            mSplitSelectListener = new DesktopSplitSelectListenerImpl(this);
             SystemUiProxy.INSTANCE.get(mLauncher).registerSplitSelectListener(mSplitSelectListener);
         }
 
         void onDestroy() {
             SystemUiProxy.INSTANCE.get(mLauncher).unregisterSplitSelectListener(
                     mSplitSelectListener);
+            mSplitSelectListener.release();
             mSplitSelectListener = null;
         }
 
@@ -1079,4 +1072,35 @@ public class SplitSelectStateController {
             }
         }
     }
+
+    /**
+     * Wrapper for the ISplitSelectListener stub to prevent lingering references to the launcher
+     * activity via the controller.
+     */
+    private static class DesktopSplitSelectListenerImpl extends ISplitSelectListener.Stub {
+
+        private SplitFromDesktopController mController;
+
+        DesktopSplitSelectListenerImpl(@NonNull SplitFromDesktopController controller) {
+            mController = controller;
+        }
+
+        /**
+         * Clears any references to the controller.
+         */
+        void release() {
+            mController = null;
+        }
+
+        @Override
+        public boolean onRequestSplitSelect(ActivityManager.RunningTaskInfo taskInfo,
+                int splitPosition, Rect taskBounds) {
+            MAIN_EXECUTOR.execute(() -> {
+                if (mController != null) {
+                    mController.enterSplitSelect(taskInfo, splitPosition, taskBounds);
+                }
+            });
+            return true;
+        }
+    }
 }