1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.gallery3d.data;
18 
19 import android.net.Uri;
20 
21 import com.android.gallery3d.app.GalleryApp;
22 
23 import java.util.concurrent.atomic.AtomicBoolean;
24 
25 // This handles change notification for media sets.
26 public class ChangeNotifier {
27 
28     private MediaSet mMediaSet;
29     private AtomicBoolean mContentDirty = new AtomicBoolean(true);
30 
ChangeNotifier(MediaSet set, Uri uri, GalleryApp application)31     public ChangeNotifier(MediaSet set, Uri uri, GalleryApp application) {
32         mMediaSet = set;
33         application.getDataManager().registerChangeNotifier(uri, this);
34     }
35 
ChangeNotifier(MediaSet set, Uri[] uris, GalleryApp application)36     public ChangeNotifier(MediaSet set, Uri[] uris, GalleryApp application) {
37         mMediaSet = set;
38         for (int i = 0; i < uris.length; i++) {
39             application.getDataManager().registerChangeNotifier(uris[i], this);
40         }
41     }
42 
43     // Returns the dirty flag and clear it.
isDirty()44     public boolean isDirty() {
45         return mContentDirty.compareAndSet(true, false);
46     }
47 
fakeChange()48     public void fakeChange() {
49         onChange(false);
50     }
51 
onChange(boolean selfChange)52     protected void onChange(boolean selfChange) {
53         if (mContentDirty.compareAndSet(false, true)) {
54             mMediaSet.notifyContentChanged();
55         }
56     }
57 }