text: /**********************************************************************
   * $Id: Edge.h 3255 2011-03-01 17:56:10Z mloskot $
   *
   * GEOS - Geometry Engine Open Source
   * http://geos.refractions.net
   *
   * Copyright (C) 2001-2002 Vivid Solutions Inc.
   * Copyright (C) 2005-2006 Refractions Research Inc.
   *
   * This is free software; you can redistribute and/or modify it under
   * the terms of the GNU Lesser General Public Licence as published
   * by the Free Software Foundation. 
   * See the COPYING file for more information.
   *
   **********************************************************************/
  
  #ifndef GEOS_PLANARGRAPH_EDGE_H
  #define GEOS_PLANARGRAPH_EDGE_H
  
  #include <geos/export.h>
  
  #include <geos/planargraph/GraphComponent.h> // for inheritance
  
  #include <vector> // for typedefs
  #include <set> // for typedefs
  #include <iosfwd> // ostream
  
  #ifdef _MSC_VER
  #pragma warning(push)
  #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
  #endif
  
  // Forward declarations
  namespace geos {
  	namespace planargraph { 
  		class DirectedEdgeStar;
  		class DirectedEdge;
  		class Edge;
  		class Node;
  	}
  }
  
  namespace geos {
  namespace planargraph { // geos.planargraph
  
  /**
   * \brief Represents an undirected edge of a PlanarGraph.
   *
   * An undirected edge in fact simply acts as a central point of reference
   * for two opposite DirectedEdge.
   * 
   * Usually a client using a PlanarGraph will subclass Edge
   * to add its own application-specific data and methods.
   */
  class GEOS_DLL Edge: public GraphComponent {
  
  public:
  
  	friend std::ostream& operator<< (std::ostream& os, const Node&);
  
  	/// Set of const Edges pointers
  	typedef std::set<const Edge *> ConstSet;
  
  	/// Set of non-const Edges pointers
  	typedef std::set<Edge *> NonConstSet;
  
  	/// Vector of non-const Edges pointers
  	typedef std::vector<Edge *> NonConstVect;
  
  	/// Vector of const Edges pointers
  	typedef std::vector<const Edge *> ConstVect;
  
  protected:
  
  	/** \brief The two DirectedEdges associated with this Edge */
  	std::vector<DirectedEdge*> dirEdge;
  
  	/**
  	 * \brief Constructs an Edge whose DirectedEdges are not yet set.
  	 *
  	 * Be sure to call setDirectedEdges(DirectedEdge, DirectedEdge)
  	 */
  
  public:
  
  	/** \brief
  	 * Constructs a Edge whose DirectedEdges are
  	 * not yet set.
  	 *
  	 * Be sure to call
  	 * {@link setDirectedEdges(DirectedEdge, DirectedEdge)}
  	 */
  	Edge(): dirEdge() {}
  
  	/**
  	 * \brief Constructs an Edge initialized with the given DirectedEdges.
  	 *
  	 * For  each DirectedEdge: sets the Edge, sets the symmetric
  	 * DirectedEdge, and adds this Edge to its from-Node.
  	 */
  	Edge(DirectedEdge *de0, DirectedEdge *de1)
  		:
  		dirEdge()
  	{
  		setDirectedEdges(de0, de1);
  	}
  
  	/**
  	 * \brief Initializes this Edge's two DirectedEdges.
  	 *
  	 * For each DirectedEdge:
  	 *  sets the Edge, sets the symmetric DirectedEdge, and
  	 *  adds this Edge to its from-Node.
  	 */
  	void setDirectedEdges(DirectedEdge *de0, DirectedEdge *de1);
  
  	/**
  	 * \brief Returns one of the DirectedEdges associated with this Edge.
  	 * @param i 0 or 1
  	 */
  	DirectedEdge* getDirEdge(int i);
  
  	/**
  	 * \brief Returns the DirectedEdge that starts from the given node,
  	 * or null if the node is not one of the two nodes associated
  	 * with this Edge.
  	 */
  	DirectedEdge* getDirEdge(Node *fromNode);
  
  	/**
  	 * \brief If <code>node</code> is one of the two nodes associated
  	 * with this Edge, returns the other node; otherwise returns null.
  	 */
  	Node* getOppositeNode(Node *node);
  };
  
  /// Print a Edge
  std::ostream& operator<<(std::ostream& os, const Edge& n); 
  
  /// For backward compatibility
  //typedef Edge planarEdge;
  
  } // namespace geos::planargraph
  } // namespace geos
  
  #ifdef _MSC_VER
  #pragma warning(pop)
  #endif
  
  #endif // GEOS_PLANARGRAPH_EDGE_H
  
  /**********************************************************************
   * $Log$
   * Revision 1.1  2006/03/21 21:42:54  strk
   * planargraph.h header split, planargraph:: classes renamed to match JTS symbols
   *
   **********************************************************************/
  
  