android - Need to know when my app send a notification -

i have app, have mainactivity(mr.obvious), service , broadcastreceiver. in mainactivity have alarmmanager this:

intent myintent = new intent(mainactivity.this, broadreceiver.class);     pendingintent pendingintent = pendingintent.getbroadcast(mainactivity.this, 0, myintent,0);      alarmmanager alarmmanager = (alarmmanager)getsystemservice(alarm_service);     alarmmanager.setrepeating(alarmmanager.elapsed_realtime_wakeup,             calendar.gettimeinmillis(),             alarmmanager.interval_half_day, pendingintent); 

in broadcastreceiver have this:

public void onreceive(context context, intent intent) {     intent service1 = new intent(context, notifyservice.class);     context.startservice(service1); } 

and in service, have this:

 public int onstartcommand(intent intent, int flags, int startid) {       notificationmanager notificationmanager = (notificationmanager) this.getapplicationcontext().getsystemservice(context.notification_service);     intent intent1 = new intent(this.getapplicationcontext(),mainactivity.class);     notification notification = new notificationcompat.builder(this)             .setticker(gettext(r.string.notification_ticker))             .setsmallicon(r.drawable.green)             .setcontenttitle(frase())             .setcontenttext(gettext(r.string.notification_text))             .setautocancel(true)             .build();     intent1.addflags(intent.flag_activity_single_top| intent.flag_activity_clear_top);     notificationmanager.notify(0, notification);} 

i want app enable button in mainactivity when user receives notification, possible?

• if in background start activity newly

intent in = new intent(this, mainactivity.class); in.putextra("state", "background"); startactivity(in); 

• get string compare , control button

• if in foreground make button object public control it

• use global variable identify mainactivity in foreground or not(using activity life cycle)

  ondistroy()     onstart()