Notifier.h

#ifndef UTIL_NOTIFIER_H
#define UTIL_NOTIFIER_H

/*
* Util Package - C++ Utilities for Scientific Computation
*
* Copyright 2010 - 2017, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/

#include <list>

namespace Util
{

   using std::list;

   // Base class for component observers
   template <typename Event> class Observer;
   
   template <typename Event>
   class Notifier
   {
   
   public:

      // Compiler default constructor.

      // Compiler destructor.
  
      void registerObserver(Observer<Event>& observer);
   
      void removeObserver(Observer<Event>& observer);
   
      void notifyObservers(const Event& event);
   
   private:
   
      std::list<Observer<Event>*> observerPtrs_;

   };
  
   /* 
   * Register an observer (add to list).
   */
   template <typename Event>
   void Notifier<Event>::registerObserver(Observer<Event>& observer)
   {
      observerPtrs_.push_back(&observer);
   }
   
   /* 
   * Remove an observer from the list.
   */
   template <typename Event>
   void Notifier<Event>::removeObserver(Observer<Event>& observer)
   {
      observerPtrs_.remove(&observer);
   }

   /* 
   * Notify observers by calling their update methods.
   */
   template <typename Event>
   void Notifier<Event>::notifyObservers(const Event& event)
   {
      typename std::list< Observer<Event>* >::iterator pos;
      pos = observerPtrs_.begin();
      while (pos != observerPtrs_.end())
      {
         (*pos)->update(event);
         ++pos;
      }
   }


}
#endif