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

4 files changed, 85 insertions, 37 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
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index 1ebe8fdfb..2ea198647 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -348,13 +348,14 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
         mFolderName.setHint(sHintText);
         // Convert to a string here to ensure that no other state associated with the text field
         // gets saved.
-        String newTitle = mFolderName.getText().toString();
-        mInfo.setTitle(newTitle);
+        mInfo.title = mFolderName.getText().toString();
+        mFolderIcon.onTitleChanged(mInfo.title);
+
         LauncherModel.updateItemInDatabase(mLauncher, mInfo);
 
         if (commit) {
             sendCustomAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED,
-                    getContext().getString(R.string.folder_renamed, newTitle));
+                    getContext().getString(R.string.folder_renamed, mInfo.title));
         }
 
         // This ensures that focus is gained every time the field is clicked, which selects all
@@ -448,7 +449,6 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
 
         mItemsInvalidated = true;
         updateTextViewFocus();
-        mInfo.addListener(this);
 
         if (!sDefaultFolderName.contentEquals(mInfo.title)) {
             mFolderName.setText(mInfo.title);
@@ -1349,6 +1349,7 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
                 mLauncher, item, mInfo.id, 0, item.cellX, item.cellY);
     }
 
+    @Override
     public void onRemove(ShortcutInfo item) {
         mItemsInvalidated = true;
         // If this item is being dragged from this open folder, we have already handled
@@ -1385,9 +1386,6 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
         updateTextViewFocus();
     }
 
-    public void onTitleChanged(CharSequence title) {
-    }
-
     public ArrayList<View> getItemsInReadingOrder() {
         if (mItemsInvalidated) {
             mItemsInReadingOrder.clear();
diff --git a/src/com/android/launcher3/folder/FolderIcon.java b/src/com/android/launcher3/folder/FolderIcon.java
index 1e4eb7f27..4a4f7cff5 100644
--- a/src/com/android/launcher3/folder/FolderIcon.java
+++ b/src/com/android/launcher3/folder/FolderIcon.java
@@ -183,10 +183,9 @@ public class FolderIcon extends FrameLayout implements FolderListener {
         folder.setFolderIcon(icon);
         folder.bind(folderInfo);
         icon.setFolder(folder);
-
-        folderInfo.addListener(icon);
-
         icon.setOnFocusChangeListener(launcher.mFocusHandler);
+
+        folderInfo.setListener(new MultiFolderListener(folder, icon));
         return icon;
     }
 
@@ -944,11 +943,13 @@ public class FolderIcon extends FrameLayout implements FolderListener {
         requestLayout();
     }
 
+    @Override
     public void onAdd(ShortcutInfo item) {
         invalidate();
         requestLayout();
     }
 
+    @Override
     public void onRemove(ShortcutInfo item) {
         invalidate();
         requestLayout();
diff --git a/src/com/android/launcher3/folder/MultiFolderListener.java b/src/com/android/launcher3/folder/MultiFolderListener.java
new file mode 100644
index 000000000..103011200
--- /dev/null
+++ b/src/com/android/launcher3/folder/MultiFolderListener.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.folder;
+
+import com.android.launcher3.FolderInfo.FolderListener;
+import com.android.launcher3.ShortcutInfo;
+
+/**
+ * An implementation of {@link FolderListener} which passes the events to 2 children.
+ */
+public class MultiFolderListener implements FolderListener {
+
+    private final FolderListener mListener1;
+    private final FolderListener mListener2;
+
+    public MultiFolderListener(FolderListener listener1, FolderListener listener2) {
+        mListener1 = listener1;
+        mListener2 = listener2;
+    }
+
+    @Override
+    public void onAdd(ShortcutInfo item) {
+        mListener1.onAdd(item);
+        mListener2.onAdd(item);
+    }
+
+    @Override
+    public void onRemove(ShortcutInfo item) {
+        mListener1.onRemove(item);
+        mListener2.onRemove(item);
+    }
+
+    @Override
+    public void onItemsChanged(boolean animate) {
+        mListener1.onItemsChanged(animate);
+        mListener2.onItemsChanged(animate);
+    }
+}