state_machine.h

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/*
 * Copyright (c) 2012, Willow Garage, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the Willow Garage, Inc. 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.
 * 
 * Author: David Gossow
 */
/*
 * state_machine.h
 *
 *  Created on: Jul 17, 2012
 *      Author: gossow
 */

#ifndef INTERACTIVE_MARKERS_STATE_MACHINE_H_
#define INTERACTIVE_MARKERS_STATE_MACHINE_H_

#include <ros/ros.h>

namespace interactive_markers
{

// Helper class for state management
template<class StateT>
class StateMachine
{
public:
  StateMachine( std::string name, StateT init_state );
  StateMachine& operator=( StateT state );
  operator StateT();
  ros::Duration getDuration();
private:
  StateT state_;
  ros::Time chg_time_;
  std::string name_;
};

template<class StateT>
StateMachine<StateT>::StateMachine( std::string name, StateT init_state )
: name_(name)
{
  operator=(init_state);
};

template<class StateT>
StateMachine<StateT>& StateMachine<StateT>::operator=( StateT state )
{
  if ( state_ != state )
  {
    ROS_DEBUG( "Setting state of %s to %lu", name_.c_str(), (int64_t)state );
    state_ = state;
    chg_time_=ros::Time::now();
  }
  return *this;
}

template<class StateT>
ros::Duration StateMachine<StateT>::getDuration()
{
  return ros::Time::now()-chg_time_;
}

template<class StateT>
StateMachine<StateT>::operator StateT()
{
  return state_;
}

}

#endif /* STATE_MACHINE_H_ */