From a96dcb0cc78257adf2ae75eabb8a00be61408784 Mon Sep 17 00:00:00 2001
From: Luca Zuccarini <acul@google.com>
Date: Tue, 23 May 2023 14:50:14 +0000
Subject: [PATCH] Remove redundant instances of depth controller.

During each app launch, a new `MyDepthController` is instantiated, which
registers two of its methods as listeners for cross window blur and
opaqueness. This controller's usefulness spans that specific animation
only, but the listeners are never unregistered. This creates conflicts
when an opaqueness signal happens, which cause the background to flicker
(see videos).

Bug: 283335820
Test: manual, see videos in the bug
Flag: not needed, bug fix
Change-Id: I3dcb0b8ff0aa77bf3183a926889d0131b17bcaa4
---
 .../launcher3/QuickstepTransitionManager.java |  3 +++
 .../statehandlers/DepthController.java        | 24 +++++++++++++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java b/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
index 977163b8b0..b1faf88664 100644
--- a/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
+++ b/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
@@ -1065,6 +1065,9 @@ public class QuickstepTransitionManager implements OnDeviceProfileChangeListener
                     new SurfaceControl.Transaction().remove(dimLayer).apply()));
         }
 
+        backgroundRadiusAnim.addListener(
+                AnimatorListeners.forEndCallback(depthController::dispose));
+
         return backgroundRadiusAnim;
     }
 
diff --git a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
index d8458c9991..7c62763943 100644
--- a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
+++ b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
@@ -84,8 +84,7 @@ public class DepthController extends BaseDepthController implements StateHandler
 
                 @Override
                 public void onViewDetachedFromWindow(View view) {
-                    CrossWindowBlurListeners.getInstance().removeListener(mCrossWindowBlurListener);
-                    mLauncher.getScrimView().removeOpaquenessListener(mOpaquenessListener);
+                    removeSecondaryListeners();
                 }
             };
             rootView.addOnAttachStateChangeListener(mOnAttachListener);
@@ -95,6 +94,27 @@ public class DepthController extends BaseDepthController implements StateHandler
         }
     }
 
+    /**
+     * Cleans up after this controller so it can be garbage collected without leaving traces.
+     */
+    public void dispose() {
+        removeSecondaryListeners();
+
+        if (mLauncher.getRootView() != null && mOnAttachListener != null) {
+            mLauncher.getRootView().removeOnAttachStateChangeListener(mOnAttachListener);
+            mOnAttachListener = null;
+        }
+    }
+
+    private void removeSecondaryListeners() {
+        if (mCrossWindowBlurListener != null) {
+            CrossWindowBlurListeners.getInstance().removeListener(mCrossWindowBlurListener);
+        }
+        if (mOpaquenessListener != null) {
+            mLauncher.getScrimView().removeOpaquenessListener(mOpaquenessListener);
+        }
+    }
+
     /**
      * Sets if the underlying activity is started or not
      */