android_frameworks_base/docs/html/training/wearables/watch-faces/configuration.jd

page.title=Providing Configuration Activities

@jd:body

<div id="tb-wrapper">
<div id="tb">
<h2>This lesson teaches you to</h2>
<ol>
  <li><a href="#Intent">Specify an Intent for Configuration Activities</a></li>
  <li><a href="#WearableActivity">Create a Wearable Configuration Activity</a></li>
  <li><a href="#CompanionActivity">Create a Companion Configuration Activity</a></li>
</ol>
<h2>You should also read</h2>
<ul>
  <li><a href="{@docRoot}design/wear/watchfaces.html">Watch Faces for Android Wear</a></li>
</ul>
</div>
</div>

<p>When users install a handheld app that contains a <a
href="{@docRoot}training/wearables/apps/index.html">wearable app</a> with watch faces, these
watch faces become available in the Android Wear companion app on the companion device and in
the watch face picker on the wearable. Users can choose the active watch face for their wearable
device by selecting it on the companion app or using the watch face picker on the wearable
device.</p>

<p>Some watch faces support configuration parameters to let users customize how the watch face
looks and behaves. For example, some watch faces let users pick a custom background color, and
watch faces that tell time for two different time zones can let users select which time zones
they are interested in.</p>

<p>Watch faces that support configuration parameters can let users customize a watch face using
an activity in the wearable app, an activity on the handheld app, or both. Users can start the
wearable configuration activity on the wearable device, and they can start the companion
configuration activity from the Android Wear companion app.</p>

<p>The digital watch face from the <em>WatchFace</em> sample in the Android SDK demonstrates how to
implement handheld and wearable configuration activities and how to update a watch face in
response to configuration changes. This sample is located in the
<code>android-sdk/samples/android-21/wearable/WatchFace</code> directory.</p>



<h2 id="Intent">Specify an Intent for Configuration Activities</h2>

<p>If your watch face includes configuration activities, add the following metadata entries to
the service declaration in the manifest file of the wearable app:</p>

<pre>
&lt;service
    android:name=".DigitalWatchFaceService" ... />
    &lt;!-- companion configuration activity -->
    &lt;meta-data
        android:name=
           "com.google.android.wearable.watchface.companionConfigurationAction"
        android:value=
           "com.example.android.wearable.watchface.CONFIG_DIGITAL" />
    &lt;!-- wearable configuration activity -->
    &lt;meta-data
        android:name=
           "com.google.android.wearable.watchface.wearableConfigurationAction"
        android:value=
           "com.example.android.wearable.watchface.CONFIG_DIGITAL" />
    ...
&lt;/service>
</pre>

<p>Provide values for these entries that are preceded by the package name of your app.
Configuration activities register intent filters for this intent, and the system fires this
intent when users want to configure your watch face.</p>

<p>If your watch face only includes a companion or a wearable configuration activity, you only
need to include the corresponding metadata entry from the example above.</p>



<h2 id="WearableActivity">Create a Wearable Configuration Activity</h2>

<p>Wearable configuration activities provide a limited set of customization choices for a
watch face, because complex menus are hard to navigate on smaller screens. Your wearable
configuration activity should provide binary choices and just a few selections to customize
the main aspects of your watch face.</p>

<p>To create a wearable configuration activity, add a new activity to your wearable app module
and declare the following intent filter in the manifest file of the wearable app:</p>

<pre>
&lt;activity
    android:name=".DigitalWatchFaceWearableConfigActivity"
    android:label="@string/digital_config_name">
    &lt;intent-filter>
        &lt;action android:name=
            "com.example.android.wearable.watchface.CONFIG_DIGITAL" />
        &lt;category android:name=
        <strong>"com.google.android.wearable.watchface.category.WEARABLE_CONFIGURATION"</strong> />
        &lt;category android:name="android.intent.category.DEFAULT" />
    &lt;/intent-filter>
&lt;/activity>
</pre>

<p>The name of the action in this intent filter must match the intent name you defined in
<a href="#Intent">Specify an Intent for Configuration Activities</a>.</p>

<p>In your configuration activity, build a simple UI that provides selections for users to
customize your watch face. When users make a selection, use the <a
href="{@docRoot}training/wearables/data-layer/index.html">Wearable Data Layer API</a> to
communicate the configuration change to the watch face activity.</p>

<p>For more details, see the <code>DigitalWatchFaceWearableConfigActivity</code> and
<code>DigitalWatchFaceUtil</code> classes in the <em>WatchFace</em> sample.</p>



<h2 id="CompanionActivity">Create a Companion Configuration Activity</h2>

<p>Companion configuration activities give users access to the full set of configuration choices
for a watch face, because it is easier to interact with complex menus on the larger screen of
a handheld device. For example, a configuration activity on a handheld device enables you to
present users with elaborate color pickers to select the background color of a watch face.</p>

<p>To create a companion configuration activity, add a new activity to your handheld app module and
declare the following intent filter in the manifest file of the handheld app:</p>

<pre>
&lt;activity
    android:name=".DigitalWatchFaceCompanionConfigActivity"
    android:label="@string/app_name">
    &lt;intent-filter>
        &lt;action android:name=
            "com.example.android.wearable.watchface.CONFIG_DIGITAL" />
        &lt;category android:name=
        <strong>"com.google.android.wearable.watchface.category.COMPANION_CONFIGURATION"</strong> />
        &lt;category android:name="android.intent.category.DEFAULT" />
    &lt;/intent-filter>
&lt;/activity>
</pre>

<p>In your configuration activity, build a UI that provides options to customize all the
configurable elements of your watch face. When users make a selection, use the <a
href="{@docRoot}training/wearables/data-layer/index.html">Wearable Data Layer API</a> to
communicate the configuration change to the watch face activity.</p>

<p>For more details, see the <code>DigitalWatchFaceCompanionConfigActivity</code> class in the
<em>WatchFace</em> sample.</p>



<h2 id="Listener">Create a Listener Service in the Wearable App</h2>

<p>To receive updated configuration parameters from the configuration activities, create a
service that implements the <code>WearableListenerService</code> interface from the <a
href="{@docRoot}training/wearables/data-layer/index.html">Wearable Data Layer API</a> in your
wearable app. Your watch face implementation can redraw the watch face when the configuration
parameters change.</p>

<p>For more details, see the <code>DigitalWatchFaceConfigListenerService</code> and
<code>DigitalWatchFaceService</code> classes in the <em>WatchFace</em> sample.</p>