android_frameworks_base/docs/html/training/auto/start/index.jd

page.title=Getting Started with Auto
page.tags="auto", "car", "automotive"
page.article=true
page.image=auto/images/assets/icons/auto_app_in_simulator.png

@jd:body

<div id="tb-wrapper">
<div id="tb">
  <h2>Dependencies and Prerequisites</h2>
  <ul>
    <li>Android 5.0 (API level 21) or higher</li>
  </ul>

  <h2>This class teaches you how to</h2>
  <ol>
    <li><a href="#dev-project">Set Up an Auto Project</a></li>
    <li><a href="#build-it">Build Auto Apps</a></li>
    <li><a href="#test-it">Run and Test Auto Apps</a></li>
  </ol>

 <h2>You should also read</h2>
 <ul>
   <li><a href="{@docRoot}design/auto/index.html">Designing for Auto</a></li>
   <li><a href="{@docRoot}training/auto/audio/index.html">Providing Audio Playback with Auto</a></li>
   <li><a href="{@docRoot}training/auto/messaging/index.html">Providing Messaging for Auto</a></li>
 </ul>
</div>
</div>

<p>Android Auto extends the Android platform into the car. When users connect
their handheld devices running Android 5.0 or higher to a compatible vehicle,
the Auto user interface provides a car-optimized Android experience on the
vehicle's screen. Users interact with compatible apps and services through
voice actions and the vehicle's input controls (like a touchscreen or dashboard
buttons).</p>

<p>Auto currently supports two types of apps:</p>

<ul>
<li><em>Audio apps</em> that allow users to browse and play music and spoken
audio content in the car.</li>
<li><em>Messaging apps</em> that receive incoming notifications, read messages
  aloud via text-to-speech, and send replies via voice input in the car.</li>
</ul>

<p>You can enable your existing audio and messaging apps developed for
phones and tablets to work in the car, without having to worry about
vehicle-specific hardware differences. To enable your app for Auto, your
app must target Android 5.0 (API level 21) or higher. Your app’s manifest must
also declare the car capabilities that it uses, such as audio playback or
messaging services. </p>

<p>This lesson describes how to start building apps for Auto, including
setting up your development environment and meeting the the minimum requirements
to enable an app to communicate with Auto.</p>

<h2 id="dev-project">Set Up an Auto Project</h2>
<p>This section describes how to create a new app or modify an existing app to
communicate with Auto.</p>

<h3 id="prerequisites">Prerequisites</h3>
<p>Before you begin building apps for Auto, you must:</p>

<ul>
<li><strong><a href="{@docRoot}sdk/installing/create-project.html">Create or
update your app project</a></strong> - Android 5.0 (API level 21) provides new
APIs for implementing audio playback and messaging that is compatible with Auto.
To access the new APIs, create a project or modify an existing project to target
Android 5.0 (API level 21) or higher. This means you must set the manifest
<a href="{@docRoot}topics/manifest/uses-sdk-element.html">{@code targetSdkVersion}</a>
to 21 or higher.
</li>
<li><strong><a href="{@docRoot}tools/support-library/setup.html">Install the
support library</a></strong> - If you are building messaging apps for Auto, you
need the {@link android.support.v4.app.NotificationCompat.CarExtender} class
contained in the
<a href="{@docRoot}tools/support-library/features.html#v4">v4 support library</a>.
This class allows you to create notifications that are compatible with Auto
devices.</li>
</ul>

<h3 id="auto-metadata">Declare Auto capabilities</h3>
<p>The Auto features that your app can access are controlled
by the settings in your app manifest and a separate XML configuration file.
Before adding Auto features to your app, you must first define the Auto
XML configuration file and add a manifest entry referencing your XML file.</p>

<h4 id="auto_xml">Define the Auto XML configuration file</h4>
<p>Specify the car capabilities that your app uses in an XML file that you
place in your project’s resources directory ({@code res/xml/}). For example, to
extend an audio application for Auto, create a file called
{@code automotive_app_desc.xml} and store it under your projects’s
{@code res/xml/} folder. The {@code automotive_app_desc.xml} file contains the
following metadata:</p>
<pre>
&lt;automotiveApp&gt;
   &lt;uses name="media" /&gt;
&lt;/automotiveApp&gt;
</pre>
<p>The {@code &lt;uses&gt;} element declares the Auto capability your app
intends to use. Multiple {@code &lt;uses&gt;} tags can be added if your
application uses multiple car capabilities. The {@code name} attribute indicates
the specific capability your app uses. The values supported are:</p>
<ul>
<li>{@code media} - The app uses the Android framework APIs to play music in
a vehicle. Set this value if you are enabling an audio app for Auto.</li>
<li>{@code notification} - The app displays message notifications in the car’s
Overview screen, allows users select a message to be read aloud, and lets them
respond through voice input. Set this value if you are enabling a messaging
app for Auto.
</ul>

<h4 id="auto_xml">Add a manifest entry</h4>
<p>In your app’s manifest ({@code AndroidManifest.xml}), provide a reference to
the Auto XML configuration file you created in the previous section. Add a
{@code "com.google.android.gms.car.application"} metadata entry under the
<a href="{@docRoot}guide/topics/manifest/application-element.html">{@code &lt;application&gt;}</a>
element that references your Auto XML configuration file. Omit the {@code .xml}
file extension when specifying the configuration filename.</p>
<p>The following code snippet shows how to include this reference in your
manifest.</p>
<pre>
&lt;application&gt;

    ...
    &lt;meta-data android:name="com.google.android.gms.car.application"
     android:resource="@xml/automotive_app_desc"/&gt;

&lt;/application&gt;
</pre>

<h2 id="build-it">Add Auto Features to Your Apps</h2>
<p>After you have completed the steps described above, you're ready to add Auto
features to your apps. See these additional topics to help you build apps for
Auto:</p>

<ul>
<li><a href="{@docRoot}training/auto/audio/index.html">Providing Audio Playback for Auto</a>
- Create apps that let users browse and play music in the car.</li>
<li><a href="{@docRoot}training/auto/messaging/index.html">Providing Messaging for Auto</a>
- Enable users to receive and reply to messages in the car.</li>
</ul>

<p class="caution"><strong>Important:</strong> Google takes driver distraction
very seriously. There are specific design requirements your app must meet to
qualify as an Auto app on Google Play. By adhering to these
requirements, you can reduce the effort for building and testing your app. For
more information, see
<a href="{@docRoot}distribute/essentials/quality/auto.html">Auto App Quality</a>.</p>

<h2 id="test-it">Run and Test Auto Apps</h2>

<p>As you prepare to publish your app, make sure that your app looks correct
when projected on the Auto user interface. Use the Android Media Browser
simulator and Android Messaging simulators to view and test your audio or
messaging apps in a screen that looks similar to what is projected on Auto.</p>

<p>To get the simulators, open the
<a href="{@docRoot}tools/help/sdk-manager.html">SDK Manager</a> and download
them from <strong>Extras &gt; Android Auto API Simulators</strong>.</p>

<p>Before you begin testing, compile your app in your development environment.
Install your app and the Android simulator for the features you want to test
(that is, audio or messaging) on a physical or virtual device running Android
5.0 (API level 21) or higher. To check the version of Android on the device, go
to <strong>Settings &gt; About &gt; Android Version</strong>.</p>

<h3 id="testing-audio-apps">Testing audio apps</h3>
<p>To run and test audio apps:</p>

<ol>
<li>Install the Android Media Browser simulator
({@code &lt;sdk&gt;/extras/google/simulators/media-browser-simulator.apk}) on
the test device. You can do this using
the <a href="{@docRoot}tools/help/adb.html#move">adb</a> command line tool.</li>
<li>Enable <a href="{@docRoot}tools/device.html#device-developer-options">
developer options</a> on the test device.</li>
<li>Install your app on the test device.</li>
<li>Launch the Android Media Browser simulator to see how your audio app
appears in Auto. If your app does not appear, stop the simulator from
<strong>Settings &gt; Apps</strong> then restart it.</li>
</ol>

<h3 id="testing-messaging-apps">Testing messaging apps</h3>
<p>To run and test messaging apps:</p>

<ol>
<li>Install the Android Messaging simulator
  ({@code &lt;sdk&gt;/extras/google/simulators/messaging-simulator.apk})
on the test device. You can do this using the
<a href="{@docRoot}tools/help/adb.html#move">adb</a> command line tool.</li>
<li>Enable the simulator to read notifications posted on the system:
<ol type="a">
	<li>Enable <a href="{@docRoot}tools/device.html#device-developer-options">
developer options</a> on the test device.</li>
	<li>Click <strong>Settings &gt; Sounds &amp; Notifications &gt; Notification
	Access</strong> and check the box labeled
	<strong>Messaging Simulator</strong>.</li>
</ol>
<li>Install your app on the test device.</li>
<li>Launch the Android Messaging Simulator to see how your messaging app appears
in Auto. If your app does not appear, stop the simulator from
<strong>Settings &gt; Apps</strong> then restart it.</li>
</ol>