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
17package com.android.gallery3d.data;
18
19import android.net.Uri;
20
21import com.android.gallery3d.app.GalleryApp;
22
23import java.util.concurrent.atomic.AtomicBoolean;
24
25// This handles change notification for media sets.
26public class ChangeNotifier {
27
28    private MediaSet mMediaSet;
29    private AtomicBoolean mContentDirty = new AtomicBoolean(true);
30
31    public ChangeNotifier(MediaSet set, Uri uri, GalleryApp application) {
32        mMediaSet = set;
33        application.getDataManager().registerChangeNotifier(uri, this);
34    }
35
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.
44    public boolean isDirty() {
45        return mContentDirty.compareAndSet(true, false);
46    }
47
48    public void fakeChange() {
49        onChange(false);
50    }
51
52    protected void onChange(boolean selfChange) {
53        if (mContentDirty.compareAndSet(false, true)) {
54            mMediaSet.notifyContentChanged();
55        }
56    }
57}