Wrapping folderLisners with weak reference, and storing it as an array

Storing as an array allows the listeners to be overriten on next bind.
These changes remove the need to unbind the item

Bug: 28740269
Change-Id: Ibbe4b760d64784fbe3075d18e2b946b366d631c5

1 files changed, 24 insertions, 27 deletions

diff --git a/src/com/android/launcher3/FolderInfo.java b/src/com/android/launcher3/FolderInfo.java
index 6c9d969a3..0dfe525b7 100644
--- a/src/com/android/launcher3/FolderInfo.java
+++ b/src/com/android/launcher3/FolderInfo.java
@@ -21,6 +21,7 @@ import android.content.Context;
 
 import com.android.launcher3.compat.UserHandleCompat;
 
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 
 /**
@@ -57,7 +58,11 @@ public class FolderInfo extends ItemInfo {
      */
     public ArrayList<ShortcutInfo> contents = new ArrayList<ShortcutInfo>();
 
-    ArrayList<FolderListener> listeners = new ArrayList<FolderListener>();
+    /**
+     * A collection of listeners for folder info changes. Since this listeners are implemented by
+     * the UI objects, using a WeakReference prevents context leaks.
+     */
+    private  WeakReference<FolderListener> mListener;
 
     public FolderInfo() {
         itemType = LauncherSettings.Favorites.ITEM_TYPE_FOLDER;
@@ -71,8 +76,9 @@ public class FolderInfo extends ItemInfo {
      */
     public void add(ShortcutInfo item, boolean animate) {
         contents.add(item);
-        for (int i = 0; i < listeners.size(); i++) {
-            listeners.get(i).onAdd(item);
+        FolderListener listener = mListener == null ? null : mListener.get();
+        if (listener != null) {
+            listener.onAdd(item);
         }
         itemsChanged(animate);
     }
@@ -84,19 +90,13 @@ public class FolderInfo extends ItemInfo {
      */
     public void remove(ShortcutInfo item, boolean animate) {
         contents.remove(item);
-        for (int i = 0; i < listeners.size(); i++) {
-            listeners.get(i).onRemove(item);
+        FolderListener listener = mListener == null ? null : mListener.get();
+        if (listener != null) {
+            listener.onRemove(item);
         }
         itemsChanged(animate);
     }
 
-    public void setTitle(CharSequence title) {
-        this.title = title;
-        for (int i = 0; i < listeners.size(); i++) {
-            listeners.get(i).onTitleChanged(title);
-        }
-    }
-
     @Override
     void onAddToDatabase(Context context, ContentValues values) {
         super.onAddToDatabase(context, values);
@@ -105,33 +105,30 @@ public class FolderInfo extends ItemInfo {
 
     }
 
-    public void addListener(FolderListener listener) {
-        listeners.add(listener);
-    }
-
-    void removeListener(FolderListener listener) {
-        if (listeners.contains(listener)) {
-            listeners.remove(listener);
-        }
+    /**
+     * Registers a listener for info change events.
+     */
+    public void setListener(FolderListener listener) {
+        mListener = new WeakReference<>(listener);
     }
 
     public void itemsChanged(boolean animate) {
-        for (int i = 0; i < listeners.size(); i++) {
-            listeners.get(i).onItemsChanged(animate);
+        FolderListener listener = mListener == null ? null : mListener.get();
+        if (listener != null) {
+            listener.onItemsChanged(animate);
         }
     }
 
     @Override
     void unbind() {
         super.unbind();
-        listeners.clear();
+        mListener = null;
     }
 
     public interface FolderListener {
-        public void onAdd(ShortcutInfo item);
-        public void onRemove(ShortcutInfo item);
-        public void onTitleChanged(CharSequence title);
-        public void onItemsChanged(boolean animate);
+        void onAdd(ShortcutInfo item);
+        void onRemove(ShortcutInfo item);
+        void onItemsChanged(boolean animate);
     }
 
     @Override