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.data.MediaSet.ItemConsumer; 22 23 import java.util.ArrayList; 24 25 public abstract class MediaSource { 26 private static final String TAG = "MediaSource"; 27 private String mPrefix; 28 MediaSource(String prefix)29 protected MediaSource(String prefix) { 30 mPrefix = prefix; 31 } 32 getPrefix()33 public String getPrefix() { 34 return mPrefix; 35 } 36 findPathByUri(Uri uri, String type)37 public Path findPathByUri(Uri uri, String type) { 38 return null; 39 } 40 createMediaObject(Path path)41 public abstract MediaObject createMediaObject(Path path); 42 pause()43 public void pause() { 44 } 45 resume()46 public void resume() { 47 } 48 getDefaultSetOf(Path item)49 public Path getDefaultSetOf(Path item) { 50 return null; 51 } 52 getTotalUsedCacheSize()53 public long getTotalUsedCacheSize() { 54 return 0; 55 } 56 getTotalTargetCacheSize()57 public long getTotalTargetCacheSize() { 58 return 0; 59 } 60 61 public static class PathId { PathId(Path path, int id)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). mapMediaItems(ArrayList<PathId> list, ItemConsumer consumer)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