Android Wear Demand

The Demand context is one of the core functions for Android Wear. A demand is displayed as a large icon, typically when you swipe a displayed suggestion (notification). You tap on an icon to perform the desired demand.

When new email arrives for example, you swipe to the left to scroll through the demand icons, such as open, reply, and archive. You can create custom icons for your app as well. This section explains how to code your own wearable demand that handles a voice reply.

First Android Wear Demand

If you have not already done so, Create a Project. The new project wizard in Android Studio creates a project with two main activities, one for the handheld device and another for the wearable. To create your first demand, add code in the handheld activity only, located in the “mobile” branch of the project hierarchy. The software preinstalled on a wearable device or emulator handles the task of displaying notifications and handling demands on the wearable side.

Add Build Dependencies

Add build dependencies for the wearable support package to the build.gradle (Module:mobile) file in Gradle Scripts folder, if necessary.

dependencies {
  compile fileTree(dir: 'libs', include: ['*.jar'])
  wearApp project(':wear')
  compile 'com.android.support:appcompat-v7:21.+'
  compile 'com.google.android.gms:play-services:6.5.+'
}

Modify the Handheld Activity

Your handheld activity initiates the process by creating a notification that includes an action (demand). When a user views the notification and invokes the demand, the wearable broadcasts the demand to the handheld for processing. You build the notification with a hierarchy of objects, intent -> pending intent -> notification action -> wearable extender, and finally the notification itself.

1. Create an Intent that defines the action that the handheld device should take in response to a wearable demand.
   The Intent has the following parameters:
   > The context of the activity, service, or broadcast receiver on the handheld that handles wearable demands.
   > The name of the class on the handheld that receives wearable demands.
   > A constant that specifies a demand action.
   > An extra with details about the requested action.
   The following example shows how to create an intent for a reply demand. The DemandIntentReceiver is defined later in Create a Demand Receiver.

public static final String ACTION_DEMAND = "com.androidweardocs.ACTION_DEMAND";
public static final String EXTRA_MESSAGE = "com.androidweardocs.EXTRA_MESSAGE";
    public static final String EXTRA_VOICE_REPLY = "com.androidweardocs.EXTRA_VOICE_REPLY";

Intent demandIntent = new Intent(this, DemandIntentReceiver.class)
  .putExtra(EXTRA_MESSAGE, “Reply selected.")
  .setAction(ACTION_DEMAND);

2. Create a PendingIntent to include in the notification.

A PendingIntent wraps the intent to grant the privileges it needs for to execute in your application. It contains the context of the activity, service, or broadcast receiver that will receive the demand, and the Intent object itself. This example creates a PendingIntent using the context of a broadcast receiver. Use getActivity instead of getBroadcast if your activity receives demands.

PendingIntent demandPendingIntent =
    PendingIntent.getBroadcast(this, 0, demandIntent, 0);

3. Create a RemoteInput object to hold a voice reply from the wearable device. A voice request or response is a common action for a wearable device because of the small size of the UI.

String replyLabel = getResources().getString(R.string.app_name);
RemoteInput remoteInput = new RemoteInput.Builder(EXTRA_VOICE_REPLY)
  .setLabel(replyLabel)
  .build();

4. Create a wearable action.

The following example creates an wearable action that uses a standard reply icon and label, adds the pending intent, and the RemoteInput object for voice.

NotificationCompat.Action replyAction =
  new NotificationCompat.Action.Builder(R.drawable.ic_reply_icon,
    getString(R.string.reply_label), demandPendingIntent)
    .addRemoteInput(remoteInput)
    .build();

5. Create a WearableExtender for the a notification and add the wearable action.

NotificationCompat.WearableExtender wearableExtender =
  new NotificationCompat.WearableExtender()
      .addAction(replyAction);

6. Create a notification and extended it with the wearable extender just created. The following example creates a notification that includes a reply action (demand).

Notification notification =
  new NotificationCompat.Builder(this)
    .setContentTitle("Hello Wearable!")
    .setContentText("First Wearable demand.")
    .setSmallIcon(R.drawable.ic_launcher)
    .extend(wearableExtender)
    .build();

7. Get an instance of the Notification Manager service.

NotificationManagerCompat notificationManager =
  NotificationManagerCompat.from(this);

8. Dispatch the extended notification.

int notificationId, notification;
notificationManager.notify(notificationId, notification);

Create a Demand Receiver

When a user makes a demand, the wearable broadcasts an intent that contains the details. The handheld receives the broadcast and takes an appropriate action. The following example defines a BroadcastReceiver for a voice demand that simply logs the results.

public class DemandIntentReceiver extends BroadcastReceiver{

  @Override
  public void onReceive(Context context, Intent intent) {

    if (intent.getAction().equals(Handheld.ACTION_DEMAND)) {String message =
              intent.getStringExtra(Handheld.EXTRA_MESSAGE);
      Log.v("MyTag","Extra message from intent = " + message);
      Bundle remoteInput = RemoteInput.getResultsFromIntent(intent);
      CharSequence reply = remoteInput.getCharSequence(Handheld.EXTRA_VOICE_REPLY);
      Log.v("MyTag", "User reply from wearable: " + reply);
      }
    }
  }

You also need to modify the manifest file to accept the broadcast. Add a receiver section within the application section.

<receiver android:name=".DemandIntentReceiver" android:exported="false">
  <intent-filter>
    <action android:name="com.androidweardocs.first_wearable.ACTION_DEMAND"/>
  </intent-filter>
    </receiver>

The sample code first displays the notification text, which is simply a title and body. Swiping to the left displays the reply icon with the reply label.