1 /* 2 * Copyright (C) 2011 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.gadget; 18 19 import android.graphics.Bitmap; 20 import android.net.Uri; 21 import android.os.Binder; 22 23 import com.android.gallery3d.common.Utils; 24 import com.android.gallery3d.data.ContentListener; 25 import com.android.gallery3d.data.MediaItem; 26 import com.android.gallery3d.data.MediaObject; 27 import com.android.gallery3d.data.MediaSet; 28 29 import java.util.ArrayList; 30 import java.util.Arrays; 31 32 public class MediaSetSource implements WidgetSource, ContentListener { 33 private static final int CACHE_SIZE = 32; 34 35 private static final String TAG = "MediaSetSource"; 36 37 private MediaSet mSource; 38 private MediaItem mCache[] = new MediaItem[CACHE_SIZE]; 39 private int mCacheStart; 40 private int mCacheEnd; 41 private long mSourceVersion = MediaObject.INVALID_DATA_VERSION; 42 43 private ContentListener mContentListener; 44 MediaSetSource(MediaSet source)45 public MediaSetSource(MediaSet source) { 46 mSource = Utils.checkNotNull(source); 47 mSource.addContentListener(this); 48 } 49 50 @Override close()51 public void close() { 52 mSource.removeContentListener(this); 53 } 54 ensureCacheRange(int index)55 private void ensureCacheRange(int index) { 56 if (index >= mCacheStart && index < mCacheEnd) return; 57 58 long token = Binder.clearCallingIdentity(); 59 try { 60 mCacheStart = index; 61 ArrayList<MediaItem> items = mSource.getMediaItem(mCacheStart, CACHE_SIZE); 62 mCacheEnd = mCacheStart + items.size(); 63 items.toArray(mCache); 64 } finally { 65 Binder.restoreCallingIdentity(token); 66 } 67 } 68 69 @Override getContentUri(int index)70 public synchronized Uri getContentUri(int index) { 71 ensureCacheRange(index); 72 if (index < mCacheStart || index >= mCacheEnd) return null; 73 return mCache[index - mCacheStart].getContentUri(); 74 } 75 76 @Override getImage(int index)77 public synchronized Bitmap getImage(int index) { 78 ensureCacheRange(index); 79 if (index < mCacheStart || index >= mCacheEnd) return null; 80 return WidgetUtils.createWidgetBitmap(mCache[index - mCacheStart]); 81 } 82 83 @Override reload()84 public void reload() { 85 long version = mSource.reload(); 86 if (mSourceVersion != version) { 87 mSourceVersion = version; 88 mCacheStart = 0; 89 mCacheEnd = 0; 90 Arrays.fill(mCache, null); 91 } 92 } 93 94 @Override setContentListener(ContentListener listener)95 public void setContentListener(ContentListener listener) { 96 mContentListener = listener; 97 } 98 99 @Override size()100 public int size() { 101 long token = Binder.clearCallingIdentity(); 102 try { 103 return mSource.getMediaItemCount(); 104 } finally { 105 Binder.restoreCallingIdentity(token); 106 } 107 } 108 109 @Override onContentDirty()110 public void onContentDirty() { 111 if (mContentListener != null) mContentListener.onContentDirty(); 112 } 113 } 114