Clean up some more refs to thumbnail data

- Always return a copy of the task list to ensure that the model doesn't
  hold refs to the thumbnail data if it was loaded into the same task
- Always clear the task thumbnail data ref once the visibility of the
  task view changes to be invisible

Bug: 132309376
Test: Enter overview scroll to the end of the list, relaunch app and take
      heap dump

Change-Id: I4437fd30172a5fe2a78c111f780163a1e6bbbb54

2 files changed, 14 insertions, 4 deletions

diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
index e7e41893cf..b26fdce92f 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
@@ -368,6 +368,9 @@ public class TaskView extends FrameLayout implements PageCallbacks, Reusable {
         } else {
             mSnapshotView.setThumbnail(null, null);
             setIcon(null);
+            // Reset the task thumbnail reference as well (it will be fetched from the cache or
+            // reloaded next time we need it)
+            mTask.thumbnail = null;
         }
     }
 
@@ -488,9 +491,6 @@ public class TaskView extends FrameLayout implements PageCallbacks, Reusable {
         mSnapshotView.setThumbnail(mTask, null);
         setOverlayEnabled(false);
         onTaskListVisibilityChanged(false);
-        if (mTask != null) {
-            mTask.thumbnail = null;
-        }
     }
 
     @Override
diff --git a/quickstep/src/com/android/quickstep/RecentTasksList.java b/quickstep/src/com/android/quickstep/RecentTasksList.java
index 3538373122..f27ba85388 100644
--- a/quickstep/src/com/android/quickstep/RecentTasksList.java
+++ b/quickstep/src/com/android/quickstep/RecentTasksList.java
@@ -84,7 +84,7 @@ public class RecentTasksList extends TaskStackChangeListener {
         final int requestLoadId = mChangeId;
         Runnable resultCallback = callback == null
                 ? () -> { }
-                : () -> callback.accept(mTasks);
+                : () -> callback.accept(copyOf(mTasks));
 
         if (mLastLoadedId == mChangeId && (!mLastLoadHadKeysOnly || loadKeysOnly)) {
             // The list is up to date, callback with the same list
@@ -183,4 +183,14 @@ public class RecentTasksList extends TaskStackChangeListener {
 
         return allTasks;
     }
+
+    private ArrayList<Task> copyOf(ArrayList<Task> tasks) {
+        ArrayList<Task> newTasks = new ArrayList<>();
+        for (int i = 0; i < tasks.size(); i++) {
+            Task t = tasks.get(i);
+            newTasks.add(new Task(t.key, t.colorPrimary, t.colorBackground, t.isDockable,
+                    t.isLocked, t.taskDescription, t.topActivity));
+        }
+        return newTasks;
+    }
 }
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