add subscriber handler and status displays

src/modules/events/send_event.cpp

@@ -64,6 +64,7 @@ int SendEvent::task_spawn(int argc, char *argv[])
 }
 
 SendEvent::SendEvent()
+	: _status_display(_subscriber_handler)
 {
 }
 
@@ -73,7 +74,8 @@ int SendEvent::start()
 		return 0;
 	}
 
-	_vehicle_command_sub = orb_subscribe(ORB_ID(vehicle_command));
+	// subscribe to the topics
+	_subscriber_handler.subscribe();
 
 	// Kick off the cycling. We can call it directly because we're already in the work queue context
 	cycle();
@@ -105,33 +107,30 @@ SendEvent::cycle_trampoline(void *arg)
 void SendEvent::cycle()
 {
 	if (should_exit()) {
-		if (_vehicle_command_sub >= 0) {
-			orb_unsubscribe(_vehicle_command_sub);
-			_vehicle_command_sub = -1;
-		}
-
+		_subscriber_handler.unsubscribe();
 		exit_and_cleanup();
 		return;
 	}
 
+	_subscriber_handler.check_for_updates();
+
 	process_commands();
 
+	_status_display.process();
+
 	work_queue(LPWORK, &_work, (worker_t)&SendEvent::cycle_trampoline, this,
 		   USEC2TICK(SEND_EVENT_INTERVAL_US));
 }
 
 void SendEvent::process_commands()
 {
-	bool updated;
-	orb_check(_vehicle_command_sub, &updated);
-
-	if (!updated) {
+	if (!_subscriber_handler.vehicle_command_updated()) {
 		return;
 	}
 
 	struct vehicle_command_s cmd;
 
-	orb_copy(ORB_ID(vehicle_command), _vehicle_command_sub, &cmd);
+	orb_copy(ORB_ID(vehicle_command), _subscriber_handler.get_vehicle_command_sub(), &cmd);
 
 	bool got_temperature_calibration_command = false, accel = false, baro = false, gyro = false;