text: /****************************************************************************
   *
   *   Copyright (c) 2018 PX4 Development Team. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name PX4 nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /**
   * @file listener.hpp
   *
   */
  
  #pragma once
  
  #include <px4_defines.h>
  #include <drivers/drv_hrt.h>
  #include <px4_app.h>
  #include <px4_config.h>
  #include <px4_log.h>
  #include <uORB/uORB.h>
  #include <string.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <inttypes.h>
  
  typedef int(*listener_print_topic_cb)(const orb_id_t &orb_id, int subscription);
  
  template <typename T>
  int listener_print_topic(const orb_id_t &orb_id, int subscription)
  {
  	T container;
  
  	int ret = orb_copy(orb_id, subscription, &container);
  
  	if (ret == PX4_OK) {
  		print_message(container);
  	}
  
  	return ret;
  }
  
  void listener(listener_print_topic_cb cb, const orb_id_t &id, unsigned num_msgs, int topic_instance,
  	      unsigned topic_interval);
  