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//////////////////////////////////////////////////////////////////////////////
// Copyright 2002-2006 Andreas Huber Doenni
// Distributed under the Boost Software License, Version 1.0. (See accompany-
// ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
// The following code implements the state-machine (this version details an
// alternative way of retrieving the elapsed time from the main program):
//
// --------------------------------
// | |
// | O Active |
// | | |<----
// | v | | EvReset
// | ---------------------------- | |
// | | | |-----
// | | Stopped | |
// | ---------------------------- |
// | | ^ |
// | | EvStartStop | EvStartStop |<-----O
// | v | |
// | ---------------------------- |
// | | | |
// | | Running | |
// | ---------------------------- |
// --------------------------------
#include <boost/statechart/event.hpp>
#include <boost/statechart/state_machine.hpp>
#include <boost/statechart/simple_state.hpp>
#include <boost/statechart/transition.hpp>
#include <boost/statechart/custom_reaction.hpp>
#include <boost/mpl/list.hpp>
#include <boost/config.hpp>
#include <ctime>
#include <iostream>
#ifdef BOOST_NO_STDC_NAMESPACE
namespace std
{
using ::time;
using ::difftime;
using ::time_t;
}
#endif
#ifdef BOOST_INTEL
# pragma warning( disable: 304 ) // access control not specified
# pragma warning( disable: 444 ) // destructor for base is not virtual
# pragma warning( disable: 981 ) // operands are evaluated in unspecified order
#endif
namespace sc = boost::statechart;
namespace mpl = boost::mpl;
struct EvStartStop : sc::event< EvStartStop > {};
struct EvReset : sc::event< EvReset > {};
struct EvGetElapsedTime : sc::event< EvGetElapsedTime >
{
public:
EvGetElapsedTime( double & time ) : time_( time ) {}
void Assign( double time ) const
{
time_ = time;
}
private:
double & time_;
};
struct Active;
struct StopWatch : sc::state_machine< StopWatch, Active > {};
struct Stopped;
struct Active : sc::simple_state< Active, StopWatch, Stopped >
{
public:
typedef sc::transition< EvReset, Active > reactions;
Active() : elapsedTime_( 0.0 ) {}
double & ElapsedTime()
{
return elapsedTime_;
}
double ElapsedTime() const
{
return elapsedTime_;
}
private:
double elapsedTime_;
};
struct Running : sc::simple_state< Running, Active >
{
public:
typedef mpl::list<
sc::custom_reaction< EvGetElapsedTime >,
sc::transition< EvStartStop, Stopped >
> reactions;
Running() : startTime_( std::time( 0 ) ) {}
~Running()
{
context< Active >().ElapsedTime() = ElapsedTime();
}
sc::result react( const EvGetElapsedTime & evt )
{
evt.Assign( ElapsedTime() );
return discard_event();
}
private:
double ElapsedTime() const
{
return context< Active >().ElapsedTime() +
std::difftime( std::time( 0 ), startTime_ );
}
std::time_t startTime_;
};
struct Stopped : sc::simple_state< Stopped, Active >
{
typedef mpl::list<
sc::custom_reaction< EvGetElapsedTime >,
sc::transition< EvStartStop, Running >
> reactions;
sc::result react( const EvGetElapsedTime & evt )
{
evt.Assign( context< Active >().ElapsedTime() );
return discard_event();
}
};
namespace
{
char GetKey()
{
char key;
std::cin >> key;
return key;
}
}
int main()
{
std::cout << "Boost.Statechart StopWatch example\n\n";
std::cout << "s<CR>: Starts/Stops stop watch\n";
std::cout << "r<CR>: Resets stop watch\n";
std::cout << "d<CR>: Displays the elapsed time in seconds\n";
std::cout << "e<CR>: Exits the program\n\n";
std::cout << "You may chain commands, e.g. rs<CR> resets and starts stop watch\n\n";
StopWatch stopWatch;
stopWatch.initiate();
char key = GetKey();
while ( key != 'e' )
{
switch( key )
{
case 'r':
{
stopWatch.process_event( EvReset() );
}
break;
case 's':
{
stopWatch.process_event( EvStartStop() );
}
break;
case 'd':
{
double elapsedTime = 0.0;
stopWatch.process_event( EvGetElapsedTime( elapsedTime ) );
std::cout << "Elapsed time: " << elapsedTime << "\n";
}
break;
default:
{
std::cout << "Invalid key!\n";
}
break;
}
key = GetKey();
}
return 0;
}
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