observer.cpp

来自「设计模式全部演示代码,都可以编译通过,通过这些例子,在研究c++下的设计模式,特」· C++ 代码 · 共 80 行

//Observer.cpp
#include "Observer.h" 
#include "Subject.h"
#include <iostream> 
#include <string> 

using namespace std;

Observer::Observer() 
{ 
	_st = '\0';
}

Observer::~Observer() 
{
}

ConcreteObserverA::ConcreteObserverA(Subject* sub) 
{ 
	_sub = sub;
	_sub->Attach(this); 
}

ConcreteObserverA::~ConcreteObserverA() 
{
	_sub->Detach(this);
	if (_sub != 0) 
	{ delete _sub; }
}

Subject* ConcreteObserverA::GetSubject() 
{ 
	return _sub; 
}

void ConcreteObserverA::PrintInfo() 
{ 
	cout<<"ConcreteObserverA observer.... "
		<<_sub->GetState()
		<<endl; 
}

void ConcreteObserverA::Update(Subject* sub) 
{ 
	_st = sub->GetState();
	PrintInfo(); 
}

ConcreteObserverB::ConcreteObserverB(Subject* sub) 
{ 
	_sub = sub;
	_sub->Attach(this); 
}

ConcreteObserverB::~ConcreteObserverB() 
{ 
	_sub->Detach(this);
	if (_sub != 0) 
	{ 
		delete _sub; 
	} 
}

Subject* ConcreteObserverB::GetSubject() 
{
	return _sub; 
}

void ConcreteObserverB::PrintInfo() 
{ 
	cout<<"ConcreteObserverB observer.... "
		<<_sub->GetState()
		<<endl; 
}

void ConcreteObserverB::Update(Subject* sub) 
{ 
	_st = sub->GetState();
	PrintInfo(); 
}