If your notification includes an action to respond with text, such as to reply to an email, it should normally launch an activity on the handheld device. However, when your notification appears on an Android Wear device, you can allow users to dictate a reply with voice input. You can also provide pre-defined text replies for the user to select.

When the user replies with voice or selects one of the available responses, the system delivers your app on the handheld the message as a string extra in the Intent you specified to be used for the action.

Define the Remote Input

To create an action that supports voice input, first create an instance of RemoteInput using the RemoteInput.Builder APIs. The RemoteInput.Builder constructor takes a string that the system will use as a key for the Intent extra that caries the reply message to your app on the handheld.

For example, here's a new RemoteInput object that provides a custom label for the voice input prompt:

// Key for the string that's delivered in the action's intent
private static final String EXTRA_VOICE_REPLY = "extra_voice_reply";

String replyLabel = getResources().getString(R.string.reply_label);

RemoteInput remoteInput = new RemoteInput.Builder(EXTRA_VOICE_REPLY)
        .setLabel(replyLabel)
        .build();

Add Pre-defined Text Responses

In addition to allowing voice input, you can provide up to five text responses the user can select for quick replies. Call setChoices() and pass it a string array.

For example, you may define some responses in a resource array:

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="reply_choices">
        <item>Yes</item>
        <item>No</item>
        <item>Maybe</item>
    </string-array>
</resources>

Then, inflate the string array and add it to the RemoteInput:

String replyLabel = getResources().getString(R.string.reply_label);
String[] replyChoices = getResources().getStringArray(R.array.reply_choices);

RemoteInput remoteInput = new RemoteInput.Builder(EXTRA_VOICE_REPLY)
        .setLabel(replyLabel)
        .setChoices(replyChoices)
        .build();

Receive Voice Input for the Primary Action

If "Reply" is your notification's primary action (defined by the setContentIntent() method), then you should attach the RemoteInput to the main action using addRemoteInputForContentIntent(). For example:

// Create intent for reply action
Intent replyIntent = new Intent(this, ReplyService.class);
PendingIntent replyPendingIntent =
        PendingIntent.getService(this, 0, replyIntent, 0);

// Build the notification
NotificationCompat.Builder replyNotificationBuilder =
        new NotificationCompat.Builder(this)
        .setSmallIcon(R.drawable.ic_new_message)
        .setContentTitle("Message from Travis")
        .setContentText("I love key lime pie!")
        .setContentIntent(replyPendingIntent);

// Create the remote input
RemoteInput remoteInput = new RemoteInput.Builder(EXTRA_VOICE_REPLY)
        .setLabel(replyLabel)
        .build();

// Create wearable notification and add remote input
Notification replyNotification =
        new WearableNotifications.Builder(replyNotificationBuilder)
        .addRemoteInputForContentIntent(replyAction)
        .build();

By using addRemoteInputForContentIntent() to add the RemoteInput object to the notification's primary action, the button that normally appears as an "Open" action becomes the "Reply" action and starts the voice input UI when users select it on Android Wear.

Receive Voice Input for a Secondary Action

If the "Reply" action is not your notification's primary action and you want to enable voice input for a secondary action, add the RemoteInput to a new action button defined by an Action object.

You should instantiate the Action with the Action.Builder() constructor, which takes an icon and text label for the action button, plus the PendingIntent the system should use to invoke your app when the user selects the action. For example:

// Create the pending intent to fire when the user selects the action
Intent replyIntent = new Intent(this, ReplyActivity.class);
PendingIntent pendingReplyIntent =
        PendingIntent.getActivity(this, 0, replyIntent, 0);

// Create the remote input
RemoteInput remoteInput = new RemoteInput.Builder(EXTRA_VOICE_REPLY)
        .setLabel(replyLabel)
        .build();

// Create the notification action
Action replyAction = new Action.Builder(R.drawable.ic_message,
        "Reply", pendingIntent)
        .addRemoteInput(remoteInput)
        .build();

After you add the RemoteInput to the Action, add the Action to the WearableNotifications.Builder using addAction(). For example:

// Create basic notification builder
NotificationCompat.Builder replyNotificationBuilder =
        new NotificationCompat.Builder(this)
        .setContentTitle("New message");

// Create the notification action and add remote input
Action replyAction = new Action.Builder(R.drawable.ic_message,
        "Reply", pendingIntent)
        .addRemoteInput(remoteInput)
        .build();

// Create wearable notification and add action
Notification replyNotification =
        new WearableNotifications.Builder(replyNotificationBuilder)
        .addAction(replyAction)
        .build();

Now, when the user selects "Reply" from an Android wearable, the system prompts for voice input (and provides the list of pre-defined replies, if provided). Once the user completes a response, the system invokes the Intent attached to the action and adds the EXTRA_VOICE_REPLY extra (the string you passed to the RemoteInput.Builder constructor) with the user's message as the string value.