Local notifications are similar to push notifications, except that they are initiated locally by the app, rather than remotely. They are useful for communicating information to the user while the app is running in the background, since they manifest themselves as pop-up notifications on supported devices.
The process for sending a notification is:
Notifications can either be set up as one-time only or as repeating.
{@code LocalNotification n = new LocalNotification(); n.setId("demo-notification"); n.setAlertBody("It's time to take a break and look at me"); n.setAlertTitle("Break Time!"); n.setAlertSound("/notification_sound_bells.mp3"); //file name must begin with notification_sound Display.getInstance().scheduleLocalNotification( n, System.currentTimeMillis() + 10 * 1000, // fire date/time LocalNotification.REPEAT_MINUTE // Whether to repeat and what frequency ); }
The resulting notification will look like
The above screenshot was taken on the iOS simulator.
The API for receiving/handling local notifications is also similar to push. Your application's main lifecycle class needs to implement the {@link com.codename1.notifications.LocalNotificationCallback} interface which includes a single method: {@link com.codename1.notifications.LocalNotificationCallback#notificationReceived(String)}
The {@literal notificationId } parameter will match the {@literal id} value of the notification as set using {@link com.codename1.notifications.LocalNotification#setId(String)}.
{@code public class BackgroundLocationDemo implements LocalNotificationCallback { //... public void init(Object context) { //... } public void start() { //... } public void stop() { //... } public void destroy() { //... } public void localNotificationReceived(String notificationId) { System.out.println("Received local notification "+notificationId); } } }
NOTE: {@link com.codename1.notifications.LocalNotificationCallback#localNotificationReceived(String)} is only called when the user responds to the notification by tapping on the alert. If the user doesn't opt to click on the notification, then this event handler will never be fired.
Repeating notifications will continue until they are canceled by the app. You can cancel a single notification by calling {@link com.codename1.ui.Display#cancelLocalNotification(String)}
Where {@literal notificationId} is the string id that was set for the notification using {@link com.codename1.notifications.LocalNotification#setId(String)}.
You can see a full sample that uses the new local notifications API here.