How to execute a method by clicking a notification

Question

I have an application with two buttons. One button that "closes" the application and one that begins the algorithm. When I click "begin" it "hides" the application and displays a notification in the notification bar. I need to be able to execute/call a method when the notification is clicked/pressed. There are a few answers for this sort of question, but they are incredibly vague and one only points to a link to the doc on BroadcastReceiver.

If you are going to leave a url to the BroadcastReceiver doc and say "read this page," please don't reply to this question. If you are going to explain how I could use BroadcastReceiver to execute a method (from within the same class that displayed the notification), please show me some code for how this could be done.

My algorithm: press a button, display notification, click notification, call a method (don't display activity). That's it.

If it's not possible, just let me know. If it is, please show me what you would do to make it possible. Something this simple shouldn't have been overlooked by the developers of the android sdk.

Answer 1

After several iterations of trial and error, I finally found a fairly straightforward and clean way to run an arbitrary method when a notification's action is clicked. In my solution, there is one class (I'll call it NotificationUtils) that creates the notification and also contains an IntentService static inner class that will run when actions on the notification are clicked. Here is my NotificationUtils class, followed by the necessary changes to AndroidManifest.xml:

public class NotificationUtils {
    public static final int NOTIFICATION_ID = 1;

    public static final String ACTION_1 = "action_1";

    public static void displayNotification(Context context) {

        Intent action1Intent = new Intent(context, NotificationActionService.class)
            .setAction(ACTION_1);

        PendingIntent action1PendingIntent = PendingIntent.getService(context, 0,
                action1Intent, PendingIntent.FLAG_ONE_SHOT);

        NotificationCompat.Builder notificationBuilder =
                new NotificationCompat.Builder(context)
                        .setSmallIcon(R.drawable.ic_launcher)
                        .setContentTitle("Sample Notification")
                        .setContentText("Notification text goes here")
                        .addAction(new NotificationCompat.Action(R.drawable.ic_launcher,
                                "Action 1", action1PendingIntent));

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
        notificationManager.notify(NOTIFICATION_ID, notificationBuilder.build());
    }

    public static class NotificationActionService extends IntentService {
        public NotificationActionService() {
            super(NotificationActionService.class.getSimpleName());
        }

        @Override
        protected void onHandleIntent(Intent intent) {
            String action = intent.getAction();
            DebugUtils.log("Received notification action: " + action);
            if (ACTION_1.equals(action)) {
                // TODO: handle action 1.
                // If you want to cancel the notification: NotificationManagerCompat.from(this).cancel(NOTIFICATION_ID);
            }
        }
}

Now just implement your actions in onHandleIntent and add the NotificationActionService to your manifest within the <application> tags:

<service android:name=".NotificationUtils$NotificationActionService" />

Summary:

• Create a class that will create the notification.
• Inside that class, add a IntentService inner classes (make sure it is static or you will get a cryptic error!) that can run any method based on the action that was clicked.
• Declare the IntentService class in your manifest.

Answer 2

On Notification click we can't get any fire event or any click listener. When we add notification in notification bar, we can set a pending intent, which fires an intent (activity/service/broadcast) upon notification click.

I have a workound solution for you, if you really don't want to display your activity then the activity which is going to start with pending intent send a broad cast from there to your parent activity and just finish the pending activity and then once broadcast receiver receives in parent activity call whatever method you want inside the receiver. For your reference..

// This is what you are going to set a pending intent which will start once
// notification is clicked. Hopes you know how to add notification bar. 
Intent notificationIntent = new Intent(this, dummy_activity.class);
notificationIntent.setAction("android.intent.action.MAIN");
notificationIntent.addCategory("android.intent.category.LAUNCHER");
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
                                notificationIntent,
                                PendingIntent.FLAG_UPDATE_CURRENT | 
                                Notification.FLAG_AUTO_CANCEL);

// Now, once this dummy activity starts send a broad cast to your parent activity and finish the pending activity
//(remember you need to register your broadcast action here to receive).
    BroadcastReceiver call_method = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                String action_name = intent.getAction();
                if (action_name.equals("call_method")) {
                    // call your method here and do what ever you want.
                }
            };
        };
        registerReceiver(call_method, new IntentFilter("call_method"));
    }
}