1
2Android MediaBrowserService Sample
3===================================
4
5This sample shows how to implement a media app that allows
6background playback of audio, and provide a media library
7that is exposed to other apps.
81. It allows other apps control media playback externally
9using MediaSession. This allows playback to be controlled by
10the Google Assistant, for example.
112. It exposes a simple music library through MediaBrowserService.
12And it provides MediaSession callbacks. This allows it to be used
13by Android Auto, for example.
14When not connected to a car, the app has a very simple UI that
15allows for playback as well as skip to previous and next tracks.
16To learn more about MediaSession and MediaBrowserService, read
17this [article on Medium](https://medium.com/google-developers/understanding-mediasession-part-4-4-dcc77c535f99)
18that goes into the architectural details of these APIs.
19
20<img src="screenshots/architecture.png" height="400" alt="Architecture Diagram"/>
21
22Introduction
23------------
24
25To 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
47To 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 &lt;uses name="media"/&gt; 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
78Pre-requisites
79--------------
80
81- Android SDK 27
82- Android Build Tools v27.0.2
83- Android Support Repository
84
85Screenshots
86-------------
87
88<img src="screenshots/1-main.png" height="400" alt="Screenshot"/> <img src="screenshots/2-notification.png" height="400" alt="Screenshot"/>
89
90Getting Started
91---------------
92
93This sample uses the Gradle build system. To build this project, use the
94"gradlew build" command or use "Import Project" in Android Studio.
95
96Support
97-------
98
99- Google+ Community: https://plus.google.com/communities/105153134372062985968
100- Stack Overflow: http://stackoverflow.com/questions/tagged/android
101
102If you've found an error in this sample, please file an issue:
103https://github.com/googlesamples/android-MediaBrowserService
104
105Patches are encouraged, and may be submitted by forking this project and
106submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
107
108License
109-------
110
111Copyright 2017 The Android Open Source Project, Inc.
112
113Licensed to the Apache Software Foundation (ASF) under one or more contributor
114license agreements.  See the NOTICE file distributed with this work for
115additional information regarding copyright ownership.  The ASF licenses this
116file to you under the Apache License, Version 2.0 (the "License"); you may not
117use this file except in compliance with the License.  You may obtain a copy of
118the License at
119
120http://www.apache.org/licenses/LICENSE-2.0
121
122Unless required by applicable law or agreed to in writing, software
123distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
124WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
125License for the specific language governing permissions and limitations under
126the License.
127