/************************************************************************
* description: 主题或者抽象通知者类，一般用一个抽象类或者一个接口实现。
它把所有对观察者对象的引用保存在一个聚集里，每个主题都
可以有任何数量的观察者。抽象主题提供一个接口，可以增加
或者删除观察者对象。
* remark:
************************************************************************/
#ifndef _SUBJECT_H_
#define _SUBJECT_H_

#include "Observer.h"
#include <list>
#include <string>
#include <iostream>
using namespace std;

class CSubject
{
public:
// 增加观察者
virtual void Attach(CObserver* pObserver) = 0;

// 移除观察者
virtual void Detach(CObserver* pObserver) = 0;

// 通知
virtual void Notify(void) = 0;
};

#endif //_SUBJECT_H_

/************************************************************************
* description: 抽象观察者类，为所有的具体观察者定义一个接口，在得到主题
的通知时更新自己
* remark:
************************************************************************/
#ifndef _OBSERVER_H_
#define _OBSERVER_H_

class CObserver
{
public:
virtual void Update() = 0;
};

#endif //_OBSERVER_H_

/************************************************************************
* description: 具体主题类或者具体通知者，将有关状态存入具体观察者对象；在
具体主题的内部状态改变时，给所有登记过的观察者发出通知。
* remark:
************************************************************************/
#ifndef _CONCRETE_SUBJECT_H_
#define _CONCRETE_SUBJECT_H_

#include "Subject.h"

class CConcreteSubject : public CSubject
{
public:

// 增加观察者
void Attach(CObserver* pObserver)
{
m_listObservers.push_back(pObserver);
}

// 移除观察者
void Detach(CObserver* pObserver)
{
m_listObservers.remove(pObserver);
}

// 通知
void Notify(void)
{
list<CObserver*>::iterator lIter;
for (lIter = m_listObservers.begin(); lIter != m_listObservers.end(); lIter++)
{
(*lIter)->Update();
}
}

void SetState(const string& strState)
{
m_strSubjectState = strState;
}

string GetState(void)
{
return m_strSubjectState;
}

private:
string m_strSubjectState;
list<CObserver*> m_listObservers;
};

#endif //_CONCRETE_SUBJECT_H_

/************************************************************************
* description: 具体观察者，实现抽象观察者角色所要求的更新接口，以便使本
身的状态与主题的状态相协调。具体观察者角色可以保存一个指
向具体主题对象的引用
* remark:
************************************************************************/
#ifndef _CONCRETE_OBSERVER_H_
#define _CONCRETE_OBSERVER_H_

#include "ConcreteSubject.h"

class CConcreteObserver : public CObserver
{
public:
CConcreteObserver(CConcreteSubject* pSubject, const string& strName)
{
m_pSubject = pSubject;
m_strName = strName;
}

void Update(void)
{
if (NULL != m_pSubject)
{
m_strObserverState = m_pSubject->GetState();
cout << "观察者【" << m_strName << "】的新通知：" << m_strObserverState << endl;
}
}

CConcreteSubject* GetSubject(void)
{
return m_pSubject;
}

void SetSubject(CConcreteSubject* pSubject)
{
m_pSubject = pSubject;
}

private:
string m_strName;
string m_strObserverState;
CConcreteSubject* m_pSubject;
};

#endif //_CONCRETE_OBSERVER_H_

// ObserverApp.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "ConcreteSubject.h"
#include "ConcreteObserver.h"

void FreeMemory(void* Pointer)
{
if (NULL != Pointer)
{
free(Pointer);
}
}

int _tmain(int argc, _TCHAR* argv[])
{
CConcreteSubject* pConcreteSubject = NULL;
pConcreteSubject = new CConcreteSubject();

CConcreteObserver* pConcreteObserver1 = NULL;
pConcreteObserver1 = new CConcreteObserver(pConcreteSubject, "Alice");

CConcreteObserver* pConcreteObserver2 = NULL;
pConcreteObserver2 = new CConcreteObserver(pConcreteSubject, "Bob");

CConcreteObserver* pConcreteObserver3 = NULL;
pConcreteObserver3 = new CConcreteObserver(pConcreteSubject, "Carey");

pConcreteSubject->Attach(pConcreteObserver1);
pConcreteSubject->Attach(pConcreteObserver2);
pConcreteSubject->Attach(pConcreteObserver3);
pConcreteSubject->Detach(pConcreteObserver3);
pConcreteSubject->SetState("快休息~");
pConcreteSubject->Notify();

system("pause");
FreeMemory(pConcreteObserver1);
FreeMemory(pConcreteObserver2);
FreeMemory(pConcreteObserver3);
FreeMemory(pConcreteSubject);

return 0;
}

/************************************************************************
* description: 具体主题类或者具体通知者，将有关状态存入具体观察者对象；在
具体主题的内部状态改变时，给所有登记过的观察者发出通知。
* remark:
************************************************************************/
#ifndef _CONCRETE_SUBJECT_H_
#define _CONCRETE_SUBJECT_H_

#include <map>
using namespace std;

class Observer;
class CSubject
{
public:
void AddObserver(Observer* pOb, void (Observer::*pMemFunc)())
{
m_MapOb.insert(pair<Observer*, void (Observer::*)()>(pOb, pMemFunc));
}

void Notify(void)
{
ObIter Iter = m_MapOb.begin();
for (; Iter != m_MapOb.end(); Iter++)
{
void (Observer::*pMemFunc)() = Iter->second;
(Iter->first->*pMemFunc)();
}
}

string GetSubject(void)
{
return m_strSubject;
}

void SetSubject(const string& strSubject)
{
m_strSubject = strSubject;
}

private:
map<Observer*, void (Observer::*)()> m_MapOb;
typedef map<Observer*, void (Observer::*)()>::iterator ObIter;

string m_strSubject;
};

#endif //_CONCRETE_SUBJECT_H_

/************************************************************************
* description:
* remark:
************************************************************************/
#ifndef _CONCRETE_OBSERVER_H_
#define _CONCRETE_OBSERVER_H_

#include <string>
#include <iostream>
using namespace std;

class Observer
{
// do nothing
};

class CSubject;
class CObserverA : public Observer
{
public:
CObserverA(const string& strName, CSubject* pSubject)
{
m_strName = strName;
m_pSubject = pSubject;
}

void UpdateOfObserverA(void)
{
if (NULL != m_pSubject)
{
cout << m_pSubject->GetSubject() << m_strName << "别打魔兽争霸了" << endl;
}
}

private:
string m_strName;
CSubject* m_pSubject;
};

class CObserverB : public Observer
{
public:
CObserverB(const string& strName, CSubject* pSubject)
{
m_strName = strName;
m_pSubject = pSubject;
}

void UpdateOfObserverB(void)
{
if (NULL != m_pSubject)
{
cout << m_pSubject->GetSubject() << m_strName << "别打魔兽世界了" << endl;
}
}

private:
string m_strName;
CSubject* m_pSubject;
};

#endif //_CONCRETE_OBSERVER_H_

// EventHandlerApp.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "Subject.h"
#include "ConcreteObserver.h"

void FreeMemory(void* Pointer)
{
if (NULL != Pointer)
{
free(Pointer);
}
}

int _tmain(int argc, _TCHAR* argv[])
{
CSubject ObjBoss;
CObserverA* pObA = NULL;
pObA = new CObserverA("Alice", &ObjBoss);
CObserverB* pObB = NULL;
pObB = new CObserverB("Bob", &ObjBoss);

ObjBoss.AddObserver(pObA, (void (Observer::*)())&CObserverA::UpdateOfObserverA);
ObjBoss.AddObserver(pObB, (void (Observer::*)())&CObserverB::UpdateOfObserverB);
ObjBoss.SetSubject("你妈喊你回家吃饭！");
ObjBoss.Notify();

system("pause");
FreeMemory(pObB);
FreeMemory(pObA);

return 0;
}