1 2 Android MediaBrowserService Sample 3 =================================== 4 5 This sample shows how to implement a media app that allows 6 background playback of audio, and provide a media library 7 that is exposed to other apps. 8 1. It allows other apps control media playback externally 9 using MediaSession. This allows playback to be controlled by 10 the Google Assistant, for example. 11 2. It exposes a simple music library through MediaBrowserService. 12 And it provides MediaSession callbacks. This allows it to be used 13 by Android Auto, for example. 14 When not connected to a car, the app has a very simple UI that 15 allows for playback as well as skip to previous and next tracks. 16 To learn more about MediaSession and MediaBrowserService, read 17 this [article on Medium](https://medium.com/google-developers/understanding-mediasession-part-4-4-dcc77c535f99) 18 that goes into the architectural details of these APIs. 19 20 <img src="screenshots/architecture.png" height="400" alt="Architecture Diagram"/> 21 22 Introduction 23 ------------ 24 25 To implement a MediaBrowserService, you need to: 26 27 - Extend MediaBrowserServiceCompat, implementing the media 28 browsing related methods onGetRoot and onLoadChildren; 29 30 - In onCreate, start a new MediaSession and call super.setSessionToken() with 31 this MediaSession's token; 32 33 - Set a MediaSession.Callback class on the MediaSession. The callback class 34 will receive all the user's actions, like play, pause, etc; 35 36 - Handle all the actual music playing using any method your app prefers 37 (for example, the Android MediaPlayer class) 38 39 - Whenever it changes, update info about the playing item and the playing 40 queue using MediaSession corresponding methods (setMetadata, 41 setPlaybackState, setQueue, setQueueTitle, etc) 42 43 - Handle AudioManager focus change events and react appropriately 44 (e.g. pause when audio focus is lost) 45 46 47 To make it compatible with Android Auto, you also need to: 48 49 - Declare a meta-data tag in AndroidManifest.xml linking to a xml resource 50 with a automotiveApp root element. For a media app, this must include 51 an <uses name="media"/> element as a child. 52 53 For example, in AndroidManifest.xml: 54 ``` 55 <meta-data android:name="com.google.android.gms.car.application" 56 android:resource="@xml/automotive_app_desc"/> 57 ``` 58 59 And in res/xml/automotive\_app\_desc.xml: 60 ``` 61 <?xml version="1.0" encoding="utf-8"?> 62 <automotiveApp> 63 <uses name="media"/> 64 </automotiveApp> 65 ``` 66 67 - Declare and export the service in AndroidManifest.xml: 68 ``` 69 <service 70 android:name=".service.MusicService" 71 android:exported="true"> 72 <intent-filter> 73 <action android:name="android.media.browse.MediaBrowserService" /> 74 </intent-filter> 75 </service> 76 ``` 77 78 Pre-requisites 79 -------------- 80 81 - Android SDK 26 82 - Android Build Tools v26.0.1 83 - Android Support Repository 84 85 Screenshots 86 ------------- 87 88 <img src="screenshots/1-main.png" height="400" alt="Screenshot"/> <img src="screenshots/2-notification.png" height="400" alt="Screenshot"/> 89 90 Getting Started 91 --------------- 92 93 This sample uses the Gradle build system. To build this project, use the 94 "gradlew build" command or use "Import Project" in Android Studio. 95 96 Support 97 ------- 98 99 - Google+ Community: https://plus.google.com/communities/105153134372062985968 100 - Stack Overflow: http://stackoverflow.com/questions/tagged/android 101 102 If you've found an error in this sample, please file an issue: 103 https://github.com/googlesamples/android-MediaBrowserService 104 105 Patches are encouraged, and may be submitted by forking this project and 106 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details. 107 108 License 109 ------- 110 111 Copyright 2017 The Android Open Source Project, Inc. 112 113 Licensed to the Apache Software Foundation (ASF) under one or more contributor 114 license agreements. See the NOTICE file distributed with this work for 115 additional information regarding copyright ownership. The ASF licenses this 116 file to you under the Apache License, Version 2.0 (the "License"); you may not 117 use this file except in compliance with the License. You may obtain a copy of 118 the License at 119 120 http://www.apache.org/licenses/LICENSE-2.0 121 122 Unless required by applicable law or agreed to in writing, software 123 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 124 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 125 License for the specific language governing permissions and limitations under 126 the License. 127
