Observable.h

/******************************************************************************
Este arquivo eh parte da implementacao do ambiente declarativo do middleware
Ginga (Ginga-NCL).

Direitos Autorais Reservados (c) 1989-2007 PUC-Rio/Laboratorio TeleMidia

Este programa eh software livre; voce pode redistribui-lo e/ou modificah-lo sob
os termos da Licenca Publica Geral GNU versao 2 conforme publicada pela Free
Software Foundation.

Este programa eh distribuido na expectativa de que seja util, porem, SEM
NENHUMA GARANTIA; nem mesmo a garantia implicita de COMERCIABILIDADE OU
ADEQUACAO A UMA FINALIDADE ESPECIFICA. Consulte a Licenca Publica Geral do
GNU versao 2 para mais detalhes.

Voce deve ter recebido uma copia da Licenca Publica Geral do GNU versao 2 junto
com este programa; se nao, escreva para a Free Software Foundation, Inc., no
endereco 59 Temple Street, Suite 330, Boston, MA 02111-1307 USA.

Para maiores informacoes:
ncl @ telemidia.puc-rio.br
http://www.ncl.org.br
http://www.ginga.org.br
http://www.telemidia.puc-rio.br
******************************************************************************
This file is part of the declarative environment of middleware Ginga (Ginga-NCL)

Copyright: 1989-2007 PUC-RIO/LABORATORIO TELEMIDIA, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License version 2 as published by
the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the GNU General Public License version 2 for more
details.

You should have received a copy of the GNU General Public License version 2
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

For further information contact:
ncl @ telemidia.puc-rio.br
http://www.ncl.org.br
http://www.ginga.org.br
http://www.telemidia.puc-rio.br
*******************************************************************************/

#ifndef _OBSERVABLE_H_
#define _OBSERVABLE_H_

#include "Observer.h"

#include <pthread.h>
#include <set>
using namespace std;

class Observable {
    private:
        set<Observer*> observers;
        pthread_mutex_t vM;

    public:
        virtual ~Observable() {
            pthread_mutex_lock(&vM);
            observers.clear();
            pthread_mutex_unlock(&vM);
            pthread_mutex_destroy(&vM);
        };

    protected:
        void createObserversVector() {
            pthread_mutex_init(&vM, NULL);
            observers.clear();
        };

    public:
        void addObserver(Observer* object) {
            pthread_mutex_lock(&vM);
            observers.insert(object);
            pthread_mutex_unlock(&vM);
        };

        void removeObserver(Observer* object) {
            set<Observer*>::iterator i;

            pthread_mutex_lock(&vM);
            i = observers.find(object);
            if (i != observers.end()) {
                observers.erase(i);
            }
            pthread_mutex_unlock(&vM);
        };

        virtual void notifyObservers(void* object) {
            set<Observer*>::iterator i;

            pthread_mutex_lock(&vM);
            i = observers.begin();
            while (i != observers.end()) {
                (*i)->update(this, object);
                ++i;
            }
            pthread_mutex_unlock(&vM);
        };
};

#endif //_OBSERVABLE_H_