//-----------------------------------------------------------------------------+
// Copyright (C), 1998-2007, Beijing Tangent Software Co. Ltd.
// = FileName	:   TGraphArc.h
// = Version	:   ver2.0
// = Author		:   xlc
// = CreateDate	:   2002-09-09
// = Description:   类的声明 图边
// = Maintainers: 
//                  
//-----------------------------------------------------------------------------+
#ifndef _TGRAPHARC_H_
#define _TGRAPHARC_H_

#ifndef _TWFLAG_H_
#include "TWFlag.h"
#endif

class TGraphNode;
class TGraphPath;

class GEOAPI TGraphArc : public TWFlag
{
public:
	TGraphArc(TGraphNode* pNode0=NULL,TGraphNode*pNode1=NULL);

	//删除时自动断开连接
	virtual ~TGraphArc();
	virtual int CmpArc(const TGraphArc&a) const;

	//子类派生函数返回0时，要保证节点相同!（注意:对于无向边节点无序!）
	bool operator==(const TGraphArc&a) const;
	bool operator!=(const TGraphArc&a) const;
	bool operator> (const TGraphArc&a) const;
	bool operator< (const TGraphArc&a) const;

	//TNode
	//支持端点相同情况(封闭Arc)
	TGraphNode* GetNode(long i);
	
	//取另一个节点（如果封闭边可能返回原节点)
	TGraphNode* GetOtherNode(TGraphNode* pNode) const;

	//限制使用
	void SetNode(long i,TGraphNode*pNode);
	bool IsValid() const;
	bool IsClosed() const;

	//Connect
	//在两端结点中记录此连接边，建立真正连接
	void Connect();
	
	//断开连接
	void UnConnect();

	//Path
	//type=0从起点出发,type=1从终点出发
	TGraphPath * FindMesh(int type=0);

protected:
	TGraphNode *m_pNode0,*m_pNode1;//两端点（对于有向边分别代表起点、终点）
};

#endif