我的Design Pattern之旅[6]：Adapter Pattern(OO)(11)

Object Adapter

ISO C++

/**//*
(C) OOMusou 2007 http://oomusou.cnblogs.com

Filename　　: DP_AdpaterPattern_Strategy_Object.cpp
Compiler　　: Visual C++ 8.0 / BCB 6.0 / gcc 3.4.2 / ISO C++
Description : Demo how to use Strategy Pattern with Adapter Pattern (Object)
Release　　 : 07/11/2007 1.0
*/
#include <iOStream>
using namespace std;

class IDrawStrategy {
public:
　virtual void draw() const = 0;
};

class Grapher {
public:
　Grapher(IDrawStrategy* drawStrategy = 0) : _drawStrategy(drawStrategy) {}

public:
　void drawShape() const;
　void setShape(IDrawStrategy* drawStrategy);

protected:
　IDrawStrategy* _drawStrategy;
};

void Grapher::drawShape() const {
　if (_drawStrategy)
　　　_drawStrategy->draw();
}

void Grapher::setShape(IDrawStrategy* drawStrategy) {
　_drawStrategy = drawStrategy;
}

class IPaint {
public:
　virtual void paint() const = 0;
};

class Triangle : public IPaint {
public:
　void paint() const;
};

void Triangle::paint() const {
　cout << "Draw Triangle" << endl;
}

class Circle : public IPaint {
public:
　void paint() const;
};

void Circle::paint() const {
　cout << "Draw Circle" << endl;
}

class Square : public IPaint {
public:
　void paint() const;
};

void Square::paint() const {
　cout << "Draw Square" << endl;
}

class DrawAdapter : public IDrawStrategy {
public:
　DrawAdapter(IPaint* adaptee = 0) : _adaptee(adaptee) {}
　virtual void draw() const;

protected:
　IPaint* _adaptee;
};

void DrawAdapter::draw() const {
　_adaptee->paint();
}

int main() {
　Grapher grapher(&DrawAdapter(&Triangle()));
　grapher.drawShape();

　grapher.setShape(&DrawAdapter(&Circle()));
　grapher.drawShape();

　grapher.setShape(&DrawAdapter(&Square()));
　grapher.drawShape();
}