c19-组合模式例.txt

C++课件,很好用的,帮助大家学习C++.

//组合模式

class Graph
{
public:
	virtual  	~Graph();

	virtual viod 	Draw();	
	virtual RECT	PaintCanvas();
	
	virtual void 	Add(Graph *) {}
	virtual void 	Remove(Graph *) {}
	virtual Graph * Items(int n) {}				
};
class Shape:public Graph
{
public:
	virtual         ~Shape();

	virtual viod 	Draw();	
	virtual RECT	PaintCanvas();
};
class Picture:public Graph
{
public:
	virutal 	~Picture();

	virtual viod 	Draw()
		{for each g in _graphs	//伪代码
			g->Darw();
		}
	virtual RECT	PaintCanvas()
		{
		RECT rect;
		SetRect(&rect,0,0,0,0);
		for each g in _graphs   //伪代码
			UnionRect(&rect,&rect,&(g->PaintCanvas()));	
		}
	
	virtual void 	Add(Graph * p) {_graphs->Add(p);}
	virtual void 	Remove(Graph * p) {_graphs->Remove(p);}
	virtual Graph * Items(int n) {return _graphs->Items[n]; } 	
private:
	list<Graph *> * _graphs;
};