Home | History | Annotate | Download | only in data 
      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 
     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