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CAVERNmisc_observer_c.hxx

/******************************************************************
 * CAVERNsoft
 * Copyright (C) 1994-2000 Electronic Visualization Laboratory,
 * all rights reserved
 * By Jason Leigh, Yong-joo Cho, Naveen Krishnaprasad, Chris Scharver,
 * Stuart Bailey, Atul Nayak, Shalini Venkataraman
 * University of Illinois at Chicago
 * 
 * This publication and its text and code may not be copied for commercial 
 * use without the express written permission of the University of Illinois
 * at Chicago
 * The contributors disclaim any representation of warranty: use this
 * code at your own risk.
 * Direct questions, comments etc to cavern@evl.uic.edu
 ******************************************************************/
 
 //  Based almost entirely on the work of Russel Winder

#ifndef _CAVERNmisc_observer_c
#define _CAVERNmisc_observer_c

#ifdef WIN32
#include <list>
using namespace std;
#else
#include <list.h>
#endif



class CAVERNmisc_subject_c ;

class CAVERNmisc_observer_c
{
 public:
  virtual ~CAVERNmisc_observer_c() {} ;  


  virtual void update(CAVERNmisc_subject_c * ) = 0 ;
 protected:
  CAVERNmisc_observer_c() {}

};

class CAVERNmisc_subject_c
{
 public:
        virtual ~CAVERNmisc_subject_c() {};

  virtual void attach(CAVERNmisc_observer_c *) ;


  virtual void detach(CAVERNmisc_observer_c *) ;


  virtual void notify() ;
 private:
  list<CAVERNmisc_observer_c *> m_ListOfObservers ;
};


inline void CAVERNmisc_subject_c::attach(CAVERNmisc_observer_c *o)
{
  m_ListOfObservers.push_back(o) ;
}

inline void CAVERNmisc_subject_c::detach(CAVERNmisc_observer_c *o)
{
  m_ListOfObservers.remove(o) ;
}

inline void CAVERNmisc_subject_c::notify() 
{
        
  for (list<CAVERNmisc_observer_c *>::iterator i = m_ListOfObservers.begin() ;
       i != m_ListOfObservers.end() ;
       ++i) {
    (*i)->update(this) ;
  }
}

#endif

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