DesignPattern/20.ObserverPattern/2.Code/Demo.h

#define __DEMO_H__
#ifdef __DEMO_H__

using namespace std;
#include <list>

// <20><><EFBFBD><EFBFBD><EFBFBD>۲<EFBFBD><DBB2><EFBFBD>
class Observer
{
public:
	virtual ~Observer() {}
	// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6><EFBFBD>·<EFBFBD><C2B7><EFBFBD>
	virtual void update() = 0;
};

// <20><><EFBFBD><EFBFBD><EFBFBD>۲<EFBFBD><DBB2><EFBFBD>
class ConcreteObserver:public Observer
{
public:
	// ʵ<><CAB5><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6><EFBFBD>·<EFBFBD><C2B7><EFBFBD>
	void update(){
		// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
	}
};

// <20><><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF>
class Subject
{
public:
	virtual ~Subject() {}
	// <20><><EFBFBD>ӹ۲<D3B9><DBB2><EFBFBD>
	void attach(Observer* obs){
		obsList.push_back(obs);
	}
	// <20>Ƴ<EFBFBD><C6B3>۲<EFBFBD><DBB2><EFBFBD>
	void detach(Observer* obs){
		obsList.remove(obs);
	}
	// <20><><EFBFBD><EFBFBD>֪ͨ<CDA8><D6AA><EFBFBD><EFBFBD>
	virtual void notify() = 0;
protected:
	// <20>۲<EFBFBD><DBB2><EFBFBD><EFBFBD>б<EFBFBD>
	list<Observer*>obsList;
};

// <20><><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF>
class ConcreteSubject :public Subject
{
public:
	// ʵ<><CAB5>֪ͨ<CDA8><D6AA><EFBFBD><EFBFBD>
	void notify(){
		// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
		// <20><><EFBFBD><EFBFBD>֪ͨ<CDA8>۲<EFBFBD><DBB2>߶<EFBFBD><DFB6><EFBFBD>
		for (int i = 0; i < obsList.size(); i++){
			obsList[i]->update();
		}
	}
};

// <20>ͻ<EFBFBD><CDBB>˴<EFBFBD><CBB4><EFBFBD>ʾ<EFBFBD><CABE>
int main()
{
	Subject  *sub = new ConcreteSubject();
	Observer *obs = new ConcreteObserver();
	sub->attach(obs);
	sub->notify();
	return 0;
}
#endif