GraphObserver.h

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/*
 * $Revision: 2027 $
 * 
 * last checkin:
 *   $Author: gutwenger $ 
 *   $Date: 2010-09-01 11:55:17 +0200 (Wed, 01 Sep 2010) $ 
 ***************************************************************/
 
#ifdef _MSC_VER
#pragma once
#endif

#ifndef OGDF_GRAPH_STRUCTURE_H
#define OGDF_GRAPH_STRUCTURE_H


#include <ogdf/basic/List.h>
#include <ogdf/basic/Graph.h>

namespace ogdf {

//
// in embedded graphs, adjacency lists are given in clockwise order.
//


//class Graph;
//class node;
//class edge;


//----------------------------------------------------------
// GraphObserver
//----------------------------------------------------------
class OGDF_EXPORT GraphObserver {
    friend class Graph;

public:
    GraphObserver() : m_pGraph(0) {}
    GraphObserver(const Graph* G) : m_pGraph(G) 
    {
        m_itGList = G->registerStructure(this);
    }//constructor
    virtual ~GraphObserver() 
    {
        if (m_pGraph) m_pGraph->unregisterStructure(m_itGList);
    }//destructor

    void reregister(const Graph *pG) {
        //small speedup: check if == m_pGraph
        if (m_pGraph) m_pGraph->unregisterStructure(m_itGList);
        if ((m_pGraph = pG) != 0) m_itGList = pG->registerStructure(this);
    }

    virtual void nodeDeleted(node v) = 0;
    virtual void nodeAdded(node v)   = 0;
    virtual void edgeDeleted(edge e) = 0;
    virtual void edgeAdded(edge e)   = 0;
    virtual void reInit()            = 0; 
    virtual void cleared()           = 0;

    const Graph*  getGraph() const {return m_pGraph;}

protected:
    const Graph* m_pGraph; 
    ListIterator<GraphObserver*> m_itGList; 


};

} //end namespace ogdf

#endif