eventHandler.hpp

/*
  ANCH Framework: ANother C++ Hack is a C++ framework based on C++11 standard
  Copyright (C) 2012 Vincent Lachenal

  This file is part of ANCH Framework.

  ANCH Framework is free software: you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  ANCH Framework 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 Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with ANCH Framework.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _ANCH_EVENTS_EVENT_HANDLER_H_
#define _ANCH_EVENTS_EVENT_HANDLER_H_

#include "events/eventBus.hpp"


namespace anch {
  namespace events {

    template<typename Event, typename Derived>
    class EventHandler: public Observer<Event> {
    private:
      std::function<void(Derived&,const Event&) noexcept> _callbackFunction;

      anch::events::EventBus<Event>* _eventBus;

    public:
      EventHandler(const std::function<void(Derived&,const Event&) noexcept>& callbackFunction,
                   bool useEventBus = false) {
        _callbackFunction = callbackFunction;
        if(useEventBus) {
          anch::events::EventBus<Event>& eventBus = anch::events::EventBus<Event>::getInstance();
          eventBus.addObserver(*this);
          _eventBus = &eventBus;
        } else {
          _eventBus = NULL;
        }
      }

      EventHandler(const std::function<void(Derived&,const Event&) noexcept>& callbackFunction,
                   anch::events::EventBus<Event>& eventBus) {
        _callbackFunction = callbackFunction;
        eventBus.addObserver(*this);
        _eventBus = &eventBus;
      }

      virtual ~EventHandler() {
        if(_eventBus != NULL) {
          _eventBus->removeObserver(*this);
        }
      }

    public:
      virtual void notify(const Event& event) noexcept {
        _callbackFunction(*static_cast<Derived*>(this), event);
      }

    };

  }
}

#endif //_ANCH_EVENTS_EVENT_HANDLER_H_