观察者模式

来源：互联网发布：剑三唐门成女捏脸数据编辑：程序博客网时间：2024/06/07 05:47
#include "stdafx.h"#include <set>class Observer;class Subject{public:virtual void attachObserver(Observer* o) = 0;virtual void detachObserver(Observer* o) = 0;virtual void notify() = 0;};class Observer{public:virtual void update(Subject* s) = 0;};class Window : public Subject{public:void attachObserver(Observer* o){mObservers.insert(o);}void detachObserver(Observer* o){mObservers.erase(o);}void notify(){for (std::set<Observer*>::const_iterator it = mObservers.begin();it!=mObservers.end();++it){(*it)->update(this);}}void OnSize(int w, int h){mWidth = w;mHeight = h;notify();}void GetSize(int &w, int &h){w = mWidth;h = mHeight;}protected:std::set<Observer*> mObservers;int mWidth, mHeight;};class Client : public Observer{public:void update(Subject* s){int w, h;Window* pWnd = (Window*)s;pWnd->GetSize(w, h);mWidth = w / 2;mHeight = h / 2;}private:int mWidth, mHeight;};class Button : public Observer{public:void update(Subject* s){int w, h;Window* pWnd = (Window*)s;pWnd->GetSize(w, h);mWidth = w / 8;mHeight = h / 8;}private:int mWidth, mHeight;};int _tmain(int argc, _TCHAR* argv[]){Window w;Client c;w.attachObserver(&c);Button btn;w.attachObserver(&btn);w.OnSize(50, 20);return 0;}
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