包装模式（Decorate）

#include <iostream>
#include <sstream>
using namespace std;
template <class T>
string MyConvertToStr(T obj) {
    stringstream ss;
    ss << obj;
    return ss.str();
}

class Beverage {
public:
    virtual string getDescription() = 0;
    virtual double cost() = 0;
protected:
    string m_Description;
};

class CondimentDecorate :public Beverage {
public:
    virtual string getDescription() = 0;
protected:
    CondimentDecorate(){}
};

//装饰类1：Soy
class Soy :public CondimentDecorate {
public:
    Soy(Beverage *pBeverage):m_pBeverage(pBeverage){}
    string getDescription() {
        return m_pBeverage->getDescription() + ",加了酱油了";

    }
    double cost() {
        return 0.1 + m_pBeverage->cost();
    }
private:
    //持有被装饰的对象
    Beverage *m_pBeverage;
};

//装饰类2：Milk
class Milk :public CondimentDecorate {
public:
    Milk(Beverage *pBeverage) :m_pBeverage(pBeverage) {}
    string getDescription() {
        return m_pBeverage->getDescription() + ",加了酱油了";

    }
    double cost() {
        return 5+ m_pBeverage->cost();
    }
private:
    //持有被装饰的对象
    Beverage *m_pBeverage;
};

class Lattee :public Beverage {
public:
    Lattee() {
        m_Description = "拿铁";
    }
    string getDescription() {
        return m_Description;
    }
    double cost() {
        return 13;
    }
};


class Expresso :public Beverage {
public:
    Expresso() {
        m_Description = "浓缩咖啡";
    }
    string getDescription() {
        return m_Description;
    }
    double cost() {
        return 13;
    }
};

class Mocha :public Beverage {
public:
    Mocha() {
        m_Description = "摩卡";
    }
    string getDescription() {
        return m_Description;
    }
    double cost() {
        return 13;
    }
};

int main(void) {
    Beverage* pBeverage = new Expresso();
    cout << pBeverage->getDescription() << "价格是" << MyConvertToStr(pBeverage->cost()) << endl;

    Beverage* pBeverage2 = new Mocha();
    pBeverage2 = new Soy(pBeverage2);
    pBeverage2 = new Soy(pBeverage2);
    cout << pBeverage2->getDescription() << "价格是" << MyConvertToStr(pBeverage2->cost()) << endl;
    system("pause");
    return 0;
}

#include <iostream>
#include <windows.h>
using namespace std;

class CView {
public:
    virtual void Draw(void){}
};

//抽象装饰类
class CDecorate :public CView {
public:
    CDecorate(CView *pView):m_pView(pView){}
    virtual void Draw(void) {
        m_pView->Draw();
    }

private:
    CView* m_pView;
};

class CScrollBars :public CDecorate {
public:
    CScrollBars(CView *pView):CDecorate(pView){}
protected:
    //绘制滚动条
    void DrawScrollBars() {
        cout << ">绘制了一个滚动条" << endl;
    }
public:
    virtual void Draw() {
        CDecorate::Draw();
        DrawScrollBars();
    }
};

class CBorder :public CDecorate {
public:
    CBorder(CView *pView) :CDecorate(pView) {}
protected:
    //绘制滚动条
    void DrawBorder() {
        cout << ">绘制了一个边框" << endl;
    }
public:
    virtual void Draw() {
        CDecorate::Draw();
        DrawBorder();
    }
};

//context->主要的被装饰对象
class CTextView :public CView {
public:
    CTextView(char* s) {
        SetWindowText(s);
    }
protected:
    virtual void DrawTextView() {
        cout << ">绘制了一个文本视图,文本的内容为" << m_Text;
    }
protected:
    char m_Text[MAX_PATH];

public:
    virtual void Draw() {
        CView::Draw();
        DrawTextView();
    }

    void SetWindowText(char* s) {
        strcpy_s(m_Text, _countof(m_Text), s);
    }

    char* GetWindowText() {
        return m_Text;
    }
};

class CWindows {
public:
    CWindows() {
        ZeroMemory(m_arrWindow, sizeof(CView*) * 10);
    }
    void Draw(){
        for (int i = 0;i < 10;i++) {
            if (m_arrWindow[i] != NULL)
                m_arrWindow[i]->Draw();
        }
    }

    void AddControl(CView* pView) {
        for (int i = 0;i < 10;i++) {
            if (m_arrWindow[i] == NULL){
                m_arrWindow[i] = pView;
                break;
            }
        }
    }

    void RemoveControl(CView* pView) {
        for (int i = 0;i < 10;i++) {
            if (m_arrWindow[i] == pView) {
                m_arrWindow[i] = NULL;
                break;
            }
        }
    }
protected:
    CView* m_arrWindow[10];

};

int main(void) {
    //定义一个窗口对象
    CWindows windowsObj;
    //定义一个普通的文本视图
    CTextView TextView("我是一个文本视图");

    windowsObj.AddControl(&TextView);
    windowsObj.Draw();
    cout << "*****************" << endl;
    windowsObj.RemoveControl(&TextView);
    CScrollBars* pScroll = new CScrollBars(&TextView);
    windowsObj.AddControl(pScroll);
    windowsObj.Draw();
    cout << "*****************" << endl;
    windowsObj.RemoveControl(pScroll);
    CBorder *pBorder = new CBorder(&TextView);
    windowsObj.AddControl(pBorder);
    windowsObj.Draw();
    system("pause");
    return 0;
}