c19-装饰模式例.txt

C++课件,很好用的,帮助大家学习C++.

//结构模式 -- 装饰

class VisualComponent
{
public:
	VisualComponent();
	virtual void Draw();
	virtual void Resize();
	//...
};

//VisualComponent的子类Decorator
class Decorator:public VisualComponent
{
public:
	Decorator(VisualComponent *);
	
	virtual void Draw() 	{_component->Draw();}
	virtual void Resize()	{_component->Resize();}
	//...
private:
	VisualComponent * _component;
};

//Decorator的子类BorderDecorator定义特殊的装饰功能
class BorderDecorator:public Decorator
{
public:
	BorderDecorator(VisualCOmponent *, int borderwidth);

	virtual void Draw() 
	{
		Decorator::Draw();
		DrawBorder(_width);
	}
private:
	void DrawBorder(int);
private:
	int 	_width;
};

VisualCOmponent * v=new VisualCOmponent;
BorderDecorator b(v,10);
b.Draw();