1 /* 2 * Copyright (C) 2017 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 androidx.leanback.widget; 18 19 import android.graphics.Bitmap; 20 21 /** 22 * Class to be implemented by app to provide seeking data and thumbnails to UI. 23 */ 24 public class PlaybackSeekDataProvider { 25 26 /** 27 * Client to receive result for {@link PlaybackSeekDataProvider#getThumbnail(int, 28 * ResultCallback)}. 29 */ 30 public static class ResultCallback { 31 32 /** 33 * Client of thumbnail bitmap being loaded. PlaybackSeekDataProvider must invoke this method 34 * in UI thread such as in {@link android.os.AsyncTask#onPostExecute(Object)}. 35 * 36 * @param bitmap Result of bitmap. 37 * @param index Index of {@link #getSeekPositions()}. 38 */ 39 public void onThumbnailLoaded(Bitmap bitmap, int index) { 40 } 41 } 42 43 /** 44 * Get a list of sorted seek positions. The positions should not change after user starts 45 * seeking. 46 * 47 * @return A list of sorted seek positions. 48 */ 49 public long[] getSeekPositions() { 50 return null; 51 } 52 53 /** 54 * Called to get thumbnail bitmap. This method is called on UI thread. When provider finds 55 * cache bitmap, it may invoke {@link ResultCallback#onThumbnailLoaded(Bitmap, int)} 56 * immediately. Provider may start background thread and invoke 57 * {@link ResultCallback#onThumbnailLoaded(Bitmap, int)} later in UI thread. The method might 58 * be called multiple times for the same position, PlaybackSeekDataProvider must guarantee 59 * to replace pending {@link ResultCallback} with the new one. When seeking right, 60 * getThumbnail() will be called with increasing index; when seeking left, getThumbnail() will 61 * be called with decreasing index. The increment of index can be used by subclass to determine 62 * prefetch direction. 63 * 64 * @param index Index of position in {@link #getSeekPositions()}. 65 * @param callback The callback to receive the result on UI thread. It may be called within 66 * getThumbnail() if hit cache directly. 67 */ 68 public void getThumbnail(int index, ResultCallback callback) { 69 } 70 71 /** 72 * Called when seek stops, Provider should cancel pending requests for the thumbnails. 73 */ 74 public void reset() { 75 } 76 } 77
