Display time-sensitive notifications

In specific situations, your app might need to get the user's attention urgently, such as an ongoing alarm or incoming call. You might have previously configured your app for this purpose by launching an activity while your app was in the background.

To provide similar behavior on a device running Android 10 (API level 29) or higher, complete the steps described in this guide.

Create a high-priority notification

When creating the notification, make sure that you include a descriptive title and message. Optionally, you can also provide a full-screen intent.

An example notification appears in the following code snippet:

val fullScreenIntent = Intent(this, CallActivity::class.java)
val fullScreenPendingIntent = PendingIntent.getActivity(this, 0,
    fullScreenIntent, PendingIntent.FLAG_UPDATE_CURRENT)

val notificationBuilder =
        NotificationCompat.Builder(this, CHANNEL_ID)
    .setSmallIcon(R.drawable.notification_icon)
    .setContentTitle("Incoming call")
    .setContentText("(919) 555-1234")
    .setPriority(NotificationCompat.PRIORITY_HIGH)
    .setCategory(NotificationCompat.CATEGORY_CALL)

    // Use a full-screen intent only for the highest-priority alerts where you
    // have an associated activity that you would like to launch after the user
    // interacts with the notification. Also, if your app targets Android 10
    // or higher, you need to request the USE_FULL_SCREEN_INTENT permission in
    // order for the platform to invoke this notification.
    .setFullScreenIntent(fullScreenPendingIntent, true)

val incomingCallNotification = notificationBuilder.build()

Intent fullScreenIntent = new Intent(this, CallActivity.class);
PendingIntent fullScreenPendingIntent = PendingIntent.getActivity(this, 0,
        fullScreenIntent, PendingIntent.FLAG_UPDATE_CURRENT);

NotificationCompat.Builder notificationBuilder =
        new NotificationCompat.Builder(this, CHANNEL_ID)
    .setSmallIcon(R.drawable.notification_icon)
    .setContentTitle("Incoming call")
    .setContentText("(919) 555-1234")
    .setPriority(NotificationCompat.PRIORITY_HIGH)
    .setCategory(NotificationCompat.CATEGORY_CALL)

    // Use a full-screen intent only for the highest-priority alerts where you
    // have an associated activity that you would like to launch after the user
    // interacts with the notification. Also, if your app targets Android 10
    // or higher, you need to request the USE_FULL_SCREEN_INTENT permission in
    // order for the platform to invoke this notification.
    .setFullScreenIntent(fullScreenPendingIntent, true);

Notification incomingCallNotification = notificationBuilder.build();

Display the notification to the user

When displaying your notification to the user, they can then choose to acknowledge or dismiss your app's alert or reminder. For example, the user can choose whether to accept or reject an incoming phone call.

If your notification is an ongoing one, such as an incoming phone call, associate the notification with a foreground service. The following code snippet shows how to display a notification that's associated with a foreground service:

// Provide a unique integer for the "notificationId" of each notification.
startForeground(notificationId, notification)

// Provide a unique integer for the "notificationId" of each notification.
startForeground(notificationId, notification);