RefreshService.java

public class RefreshService extends Service {
    public void refreshTimeline() {
	//build the intent with new messages
	this.sendOrderedBroadcast(intent, null);
    }
}

TimelineActivity.java

public class TimelineActivity {
    private RefreshTimelineReceiver refreshReceiver;
    private RefreshTimelineAndNotifyReceiver refreshAndNotifyReceiver;
	
    protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	IntentFilter filter = new IntentFilter(RefreshService.REFRESH_TIMELINE);
        filter.setPriority(FILTER_LOW_PRIORITY);
        refreshAndNotifyReceiver = new RefreshTimelineAndNotifyReceiver();
        registerReceiver(refreshAndNotifyReceiver, filter);
    }
	
    public void onResume() {
        super.onResume();
        IntentFilter filter = new IntentFilter(RefreshService.REFRESH_TIMELINE);
        filter.setPriority(FILTER_HIGH_PRIORITY);
        refreshReceiver = new RefreshTimelineReceiver();
        registerReceiver(refreshReceiver, filter);
    }
    
    public void onPause() {
        super.onPause();
        unregisterReceiver(refreshReceiver);
    }
    
    public void onDestroy() {
        super.onDestroy();
        unregisterReceiver(refreshAndNotifyReceiver);
    }
    
    public class RefreshTimelineReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            showNewMessages();
            this.abortBroadcast();
        }
    }
    
    public class RefreshTimelineAndNotifyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            showNewMessages();
            showNotification();           
        }
    }
}