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.data.MediaSet.ItemConsumer;
22
23import java.util.ArrayList;
24
25public abstract class MediaSource {
26    private static final String TAG = "MediaSource";
27    private String mPrefix;
28
29    protected MediaSource(String prefix) {
30        mPrefix = prefix;
31    }
32
33    public String getPrefix() {
34        return mPrefix;
35    }
36
37    public Path findPathByUri(Uri uri, String type) {
38        return null;
39    }
40
41    public abstract MediaObject createMediaObject(Path path);
42
43    public void pause() {
44    }
45
46    public void resume() {
47    }
48
49    public Path getDefaultSetOf(Path item) {
50        return null;
51    }
52
53    public long getTotalUsedCacheSize() {
54        return 0;
55    }
56
57    public long getTotalTargetCacheSize() {
58        return 0;
59    }
60
61    public static class PathId {
62        public PathId(Path path, int id) {
63            this.path = path;
64            this.id = id;
65        }
66        public Path path;
67        public int id;
68    }
69
70    // Maps a list of Paths (all belong to this MediaSource) to MediaItems,
71    // and invoke consumer.consume() for each MediaItem with the given id.
72    //
73    // This default implementation uses getMediaObject for each Path. Subclasses
74    // may override this and provide more efficient implementation (like
75    // batching the database query).
76    public void mapMediaItems(ArrayList<PathId> list, ItemConsumer consumer) {
77        int n = list.size();
78        for (int i = 0; i < n; i++) {
79            PathId pid = list.get(i);
80            MediaObject obj;
81            synchronized (DataManager.LOCK) {
82                obj = pid.path.getObject();
83                if (obj == null) {
84                    try {
85                        obj = createMediaObject(pid.path);
86                    } catch (Throwable th) {
87                        Log.w(TAG, "cannot create media object: " + pid.path, th);
88                    }
89                }
90            }
91            if (obj != null) {
92                consumer.consume(pid.id, (MediaItem) obj);
93            }
94        }
95    }
96}
97