|
| 1 | +/* |
| 2 | + * Copyright 2025 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 | + * https://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.media3.docsamples |
| 18 | + |
| 19 | +import android.os.Bundle |
| 20 | +import androidx.annotation.OptIn |
| 21 | +import androidx.appcompat.app.AppCompatActivity |
| 22 | +import androidx.media3.common.C |
| 23 | +import androidx.media3.common.MediaItem |
| 24 | +import androidx.media3.common.util.UnstableApi |
| 25 | +import androidx.media3.exoplayer.ExoPlayer |
| 26 | +import androidx.media3.exoplayer.source.preload.DefaultPreloadManager |
| 27 | +import androidx.media3.exoplayer.source.preload.TargetPreloadStatusControl |
| 28 | +import java.lang.Math.abs |
| 29 | + |
| 30 | +// constants to make the code snippets work |
| 31 | +const val currentPlayingIndex = 10 |
| 32 | + |
| 33 | +@UnstableApi |
| 34 | +// [START android_defaultpreloadmanager_MyTargetPreloadStatusControl] |
| 35 | +class MyTargetPreloadStatusControl(currentPlayingIndex: Int = C.INDEX_UNSET) : |
| 36 | + TargetPreloadStatusControl<Int, DefaultPreloadManager.PreloadStatus> { |
| 37 | + |
| 38 | + override fun getTargetPreloadStatus(index: Int): DefaultPreloadManager.PreloadStatus { |
| 39 | + if (index - currentPlayingIndex == 1) { // next track |
| 40 | + // return a PreloadStatus that is labelled by STAGE_SPECIFIED_RANGE_LOADED and |
| 41 | + // suggest loading 3000ms from the default start position |
| 42 | + return DefaultPreloadManager.PreloadStatus.specifiedRangeLoaded(3000L) |
| 43 | + } else if (index - currentPlayingIndex == -1) { // previous track |
| 44 | + // return a PreloadStatus that is labelled by STAGE_SPECIFIED_RANGE_LOADED and |
| 45 | + // suggest loading 3000ms from the default start position |
| 46 | + return DefaultPreloadManager.PreloadStatus.specifiedRangeLoaded(3000L) |
| 47 | + } else if (abs(index - currentPlayingIndex) == 2) { |
| 48 | + // return a PreloadStatus that is labelled by STAGE_TRACKS_SELECTED |
| 49 | + return DefaultPreloadManager.PreloadStatus.PRELOAD_STATUS_TRACKS_SELECTED |
| 50 | + } else if (abs(index - currentPlayingIndex) <= 4) { |
| 51 | + // return a PreloadStatus that is labelled by STAGE_SOURCE_PREPARED |
| 52 | + return DefaultPreloadManager.PreloadStatus.PRELOAD_STATUS_SOURCE_PREPARED |
| 53 | + } |
| 54 | + return DefaultPreloadManager.PreloadStatus.PRELOAD_STATUS_NOT_PRELOADED |
| 55 | + } |
| 56 | +} |
| 57 | + |
| 58 | +// [END android_defaultpreloadmanager_MyTargetPreloadStatusControl] |
| 59 | + |
| 60 | +class PreloadManagerSnippetsKotlin { |
| 61 | + |
| 62 | + class PreloadSnippetsActivity : AppCompatActivity() { |
| 63 | + private val context = this |
| 64 | + |
| 65 | + @OptIn(UnstableApi::class) |
| 66 | + override fun onCreate(savedInstanceState: Bundle?) { |
| 67 | + super.onCreate(savedInstanceState) |
| 68 | + |
| 69 | + // [START android_defaultpreloadmanager_createPLM] |
| 70 | + val targetPreloadStatusControl = MyTargetPreloadStatusControl() |
| 71 | + val preloadManagerBuilder = DefaultPreloadManager.Builder(context, targetPreloadStatusControl) |
| 72 | + val preloadManager = preloadManagerBuilder.build() |
| 73 | + // [END android_defaultpreloadmanager_createPLM] |
| 74 | + |
| 75 | + val player = preloadManagerBuilder.buildExoPlayer() |
| 76 | + |
| 77 | + // [START android_defaultpreloadmanager_addMedia] |
| 78 | + val initialMediaItems = pullMediaItemsFromService(count = 20) |
| 79 | + for (index in 0 until initialMediaItems.size) { |
| 80 | + preloadManager.add(initialMediaItems.get(index), /* rankingData= */ index) |
| 81 | + } |
| 82 | + // items aren't actually loaded yet! need to call invalidate() after this |
| 83 | + // [END android_defaultpreloadmanager_addMedia] |
| 84 | + |
| 85 | + // [START android_defaultpreloadmanager_invalidate] |
| 86 | + preloadManager.invalidate() |
| 87 | + // [END android_defaultpreloadmanager_invalidate] |
| 88 | + } |
| 89 | + |
| 90 | + @OptIn(UnstableApi::class) |
| 91 | + private fun fetchMedia( |
| 92 | + preloadManager: DefaultPreloadManager, |
| 93 | + mediaItem: MediaItem, |
| 94 | + player: ExoPlayer, |
| 95 | + currentIndex: Int, |
| 96 | + ) { |
| 97 | + // [START android_defaultpreloadmanager_getAndPlayMedia] |
| 98 | + // When a media item is about to display on the screen |
| 99 | + val mediaSource = preloadManager.getMediaSource(mediaItem) |
| 100 | + if (mediaSource != null) { |
| 101 | + player.setMediaSource(mediaSource) |
| 102 | + } else { |
| 103 | + // If mediaSource is null, that mediaItem hasn't been added to the preload manager |
| 104 | + // yet. So, send it directly to the player when it's about to play |
| 105 | + player.setMediaItem(mediaItem) |
| 106 | + } |
| 107 | + player.prepare() |
| 108 | + |
| 109 | + // When the media item is displaying at the center of the screen |
| 110 | + player.play() |
| 111 | + preloadManager.setCurrentPlayingIndex(currentIndex) |
| 112 | + |
| 113 | + // Need to call invalidate() to update the priorities |
| 114 | + preloadManager.invalidate() |
| 115 | + // [END android_defaultpreloadmanager_getAndPlayMedia] |
| 116 | + } |
| 117 | + |
| 118 | + @OptIn(UnstableApi::class) |
| 119 | + private fun removeMedia(mediaItem: MediaItem, preloadManager: DefaultPreloadManager) { |
| 120 | + // [START android_defaultpreloadmanager_removeItem] |
| 121 | + preloadManager.remove(mediaItem) |
| 122 | + // [END android_defaultpreloadmanager_removeItem] |
| 123 | + } |
| 124 | + |
| 125 | + @OptIn(UnstableApi::class) |
| 126 | + private fun releasePLM(preloadManager: DefaultPreloadManager) { |
| 127 | + // [START android_defaultpreloadmanager_releasePLM] |
| 128 | + preloadManager.release() |
| 129 | + // [END android_defaultpreloadmanager_releasePLM] |
| 130 | + } |
| 131 | + |
| 132 | + // no-op methods to support the code snippets |
| 133 | + private fun pullMediaItemsFromService(count: Int): List<MediaItem> { |
| 134 | + return listOf() |
| 135 | + } |
| 136 | + } |
| 137 | +} |
0 commit comments