After geofence transition how do i do something on main Activity?

Question

When someone enters one of my geofences I want to make a layout visible over my map and start playing some audio. I have been following some tutorials and I know how to do push

Answer 1

Use LocalBroadcastManager to send a broadcast to any Context that has to listen to the events. Here's an example of what you should do in your Activity:

public class MyActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceBundle);
        //Your code here

        LocalBroadcastManager lbc = LocalBroadcastManager.getInstance(this);
        GoogleReceiver googleReceiver = new GoogleReceiver(this);
        lbc.registerReceiver(googleReceiver, new IntentFilter("googlegeofence"));
        //Anything with this intent will be sent to this receiver
    
    }

    static class GoogleReceiver extends BroadcastReceiver{

        MyActivity mActivity;

        public GoogleReceiver(Activity activity){
            mActivity = (MyActivity)activity;
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            //Handle the intent here
        }
    }
}

And here is what you should put down for your intentservice:

public class GeofenceTransitionsIntentService extends IntentService {

//Any stuff you need to do here    

@Override
protected void onHandleIntent(Intent intent) {
    GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);

    //Collect all the stuff you want to send to activity here


    Intent lbcIntent = new Intent("googlegeofence"); //Send to any reciever listening for this

    lbcIntent.putExtra("Key", Value);  //Put whatever it is you want the activity to handle

    LocalBroadcastManager.getInstance(this).sendBroadcast(lbcIntent);  //Send the intent
}