Boost based event system framework (2012)

Powrót do: Fragmenty kodów

System ten umożliwia w elastyczny sposób wykorzystać elementy programowania zdarzeniowego w dowolnej aplikacji, jest on swoją drogą częścią opracowywanego przeze mnie w wolnych chwilach frameworku.

Jego implementacja sprowadza się do jednego pliku nagłówkowego

cBaseEvent.h

#pragma once #include "stdafx.h" #include <boost/signal.hpp> #include <boost/bind.hpp> #include <boost/function.hpp> namespace Events { namespace Base { class _DLLExportCore cEventArgs { public: cEventArgs() { m_isValid = true; } virtual ~cEventArgs() { }; bool IsValid() const { return m_isValid; } private: bool m_isValid; }; class cEvent { typedef boost::signal<void (cEventArgs&)> TSignal; public: int GetNumSlots() const { return m_event.num_slots(); } void Invoke( cEventArgs& args = cEventArgs() ) { m_event( args ); } template<typename Class> void RegisterHandler (Class *t, void (Class::*FNMETHOD) ( cEventArgs& ) ) { m_event.connect(boost::bind( FNMETHOD, t,_1)); } template<typename Class> void UnregisterHandler (Class *t, void (Class::*FNMETHOD) ( cEventArgs& ) ) { m_event.disconnect(boost::bind( FNMETHOD, t,_1)); } void UnregisterAllHandlers() { m_event.disconnect_all_slots(); } private: TSignal m_event; }; } };

Przykład zastosowania:

class cArgs : public Events::Base::cEventArgs
{
public:
	cArgs( int a, int b ) { m_a = a; m_b = b; }
	void Print() { std::cout << "a="<<m_a<<" and b="<<m_b<<std::endl; }

protected:
	int m_a;
	int m_b;
};

Events::Base::cEvent myEvent1;

class cA
{
public:

	void StartListeningForEvents()
	{
		myEvent1.RegisterHandler<cA>( this, &cA::OnMyEvent1);
	}

	void StopListeningForEvents()
	{
		myEvent1.UnregisterHandler<cA>( this, &cA::OnMyEvent1);
	}

	void OnMyEvent1( Events::Base::cEventArgs& a )
	{
		cArgs& args = (cArgs&)a;
		a.Print();
	}
};

void main()
{
	cA aa;
	aa.StartListeningForEvents();
	cArgs args(4, 6);
	myEvent.Invoke(args); // will call OnMyEvent1, thus outputing 'a=4 and b=6'
	aa.StopListeningForEvents();
	myEvent.Invoke(args); // event handler for this class was previously unregistered, this invoke will have no outcome
}

#pragma once
#include „stdafx.h”
#include <boost/signal.hpp>
#include <boost/bind.hpp>
#include <boost/function.hpp>
#include <iostream>

namespace Events
{
namespace Base
{
class _DLLExportCore cEventArgs
{
public:
cEventArgs() { m_isValid = true; }
virtual ~cEventArgs() { };
bool IsValid() const { return m_isValid; }

private:
bool m_isValid;
};

class cEvent
{
typedef boost::signal<void (cEventArgs&)> TSignal;
public:
int GetNumSlots() const
{
return m_event.num_slots();
}

void Invoke( cEventArgs& args = cEventArgs() )
{
std::cout<<”invoke”<<std::endl;
size_t ns = m_event.num_slots();
m_event( args );
}

template<typename Class>
void RegisterHandler (Class *t, void (Class::*FNMETHOD) ( cEventArgs& ) )
{
std::cout<<”connect”<<std::endl;

m_event.connect(
boost::bind( FNMETHOD, t,_1));
}

template<typename Class>
void UnregisterHandler (Class *t, void (Class::*FNMETHOD) ( cEventArgs& ) )
{
std::cout<<”dissconnect”<<std::endl;

m_event.disconnect(
boost::bind( FNMETHOD, t,_1));
}

void UnregisterAllHandlers()
{
std::cout<<”disconnect_all_slots”<<std::endl;
m_event.disconnect_all_slots();
}

private:
TSignal m_event;
};
}
};#pragma once
#include „stdafx.h”
#include <boost/signal.hpp>
#include <boost/bind.hpp>
#include <boost/function.hpp>
#include <iostream>