用标准C++实现信号与槽机制 笔记
用标准C++实现信号与槽机制
信号对象保存参数,以及槽对象列表.
对信号而言槽的类型只与函数指针的参数类型相关.
槽保存被绑定的对象,以及需要转发调用的函数指针.
只有绑定时才知道被绑定对象的类型.
绑定时,根据被绑定的对象由模板动态生成槽对象.
构建一个槽时,被绑定的对象的类型的信息,作为模板参数生成槽对象.
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
template<class T1>
class SlotBase
{
public:
virtual void Exec(T1 param1) = 0; virtual ~SlotBase();
};
template<class T, class T1>
class SlotImpl : public SlotBase<T1>
{
public:
SlotImpl(T* pObj, void (T::*func)(T1) )
{
m_pObj = pObj;
m_Func = func;
}
void Exec( T1 param1)
{
(m_pObj->*m_Func)(param1);
}
private:
T* m_pObj;
void (T::*m_Func)(T1);
};
template<class T1>
class Signal
{
public:
template<class T>
void Bind(T* pObj, void (T::*func)(T1))
{
m_pSlotSet.push_back( new SlotImpl<T,T1>(pObj,func) );
}
~Signal()
{
for(int i=0;i<(int)m_pSlotSet.size();i++)
{
delete m_pSlotSet[i];
}
}
void operator()(T1 param1)
{
for(int i=0;i<(int)m_pSlotSet.size();i++)
{
m_pSlotSet[i]->Exec(param1);
}
}
private:
vector< SlotBase<T1>* > m_pSlotSet;
};
#define Connect( sender, signal, receiver, method) ( (sender)->signal.Bind(receiver, method) )
class A
{
public:
void FuncOfA(int param)
{
printf("A::FuncOfA(%d)\n", param);
}
};
class B
{
public:
void FuncOfB(int param)
{
printf("B::FuncOfB(%d)\n", param);
}
};
class C
{
public:
C()
{
m_Value = 0;
}
void SetValue(int value)
{
if(m_Value != value)
{
m_Value = value;
ValueChanged(m_Value);
}
}
public:
Signal<int> ValueChanged;
private:
int m_Value;
};
int testsignal()
{
A* pA = new A;
B* pB = new B;
C* pC = new C;
Connect(pC, ValueChanged, pA, &A::FuncOfA);
Connect(pC, ValueChanged, pB, &B::FuncOfB);
pC->SetValue(10);
pC->SetValue(5);
pC->SetValue(5);
delete pC;
delete pB;
delete pA;
scanf("%*s");
}
下面是原文
以前一直以为用标准C++无法实现类似委托或者信号与槽的机制。
还写过一篇BLOG http://www.cnitblog.com/luckydmz/archive/2009/11/23/62785.html看来我还是“太年轻”，无知啊。
#include < algorithm >
#include < iostream >
#include < vector >
using namespace std;
template < class T1 >
class SlotBase
{
public :
virtual void Exec(T1 param1) = 0 ;
};
template < class T, class T1 >
class SlotImpl : public SlotBase < T1 >
{
public :
SlotImpl(T * pObj, void (T:: * func)(T1) )
{
m_pObj = pObj;
m_Func = func;
}
void Exec( T1 param1)
{
(m_pObj ->* m_Func)(param1);
}
private :
T * m_pObj;
void (T:: * m_Func)(T1);
};
template < class T1 >
class Slot
{
public :
template < class T >
Slot(T * pObj, void (T:: * func)(T1))
{
m_pSlotBase = new SlotImpl < T,T1 > (pObj, func);
}
~ Slot()
{
delete m_pSlotBase;
}
void Exec(T1 param1)
{
m_pSlotBase -> Exec(param1);
}
private :
SlotBase < T1 >* m_pSlotBase;
};
template < class T1 >
class Signal
{
public :
template < class T >
void Bind(T * pObj, void (T:: * func)(T1))
{
m_pSlotSet.push_back( new Slot < T1 > (pObj,func) );
}
~ Signal()
{
for ( int i = 0 ;i < ( int )m_pSlotSet.size();i ++ )
{
delete m_pSlotSet[i];
}
}
void operator ()(T1 param1)
{
for ( int i = 0 ;i < ( int )m_pSlotSet.size();i ++ )
{
m_pSlotSet[i] -> Exec(param1);
}
}
private :
vector < Slot < T1 >* > m_pSlotSet;
};
#define Connect( sender, signal, receiver, method) ( (sender)->signal.Bind(receiver, method) )
class A
{
public :
void FuncOfA( int param)
{
printf( " A::FuncOfA(%d)\n " , param);
}
};
class B
{
public :
void FuncOfB( int param)
{
printf( " B::FuncOfB(%d)\n " , param);
}
};
class C
{
public :
C()
{
m_Value = 0 ;
}
void SetValue( int value)
{
if (m_Value != value)
{
m_Value = value;
ValueChanged(m_Value);
}
}
public :
Signal < int > ValueChanged;
private :
int m_Value;
};
int main()
{
A * pA = new A;
B * pB = new B;
C * pC = new C;
Connect(pC, ValueChanged, pA, & A::FuncOfA);
Connect(pC, ValueChanged, pB, & B::FuncOfB);
pC -> SetValue( 10 );
pC -> SetValue( 5 );
pC -> SetValue( 5 );
delete pC;
delete pB;
delete pA;
scanf( " %*s " );
}