Event.h

/*
 * Copyright (C) 2008-2013 by Marc Boris Duerner
 * 
 * This library 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 2.1 of the License, or (at your option) any later version.
 * 
 * As a special exception, you may use this file as part of a free
 * software library without restriction. Specifically, if other files
 * instantiate templates or use macros or inline functions from this
 * file, or you compile this file and link it with other files to
 * produce an executable, this file does not by itself cause the
 * resulting executable to be covered by the GNU General Public
 * License. This exception does not however invalidate any other
 * reasons why the executable file might be covered by the GNU Library
 * General Public License.
 * 
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef PT_EVENT_H
#define PT_EVENT_H

#include <Pt/Api.h>
#include <Pt/Types.h>
#include <Pt/Allocator.h>
#include <typeinfo>
#include <new>

namespace Pt {

class Event
{
    public:
        virtual ~Event()
        {}

        Event& clone(Allocator& allocator) const
        { return onClone(allocator); }

        void destroy(Allocator& allocator)
        { onDestroy(allocator); }

        const std::type_info& typeInfo() const
        { return onTypeInfo(); }

    protected:
        Event()
        {}
        
        virtual Event& onClone(Allocator& allocator) const = 0;

        virtual void onDestroy(Allocator& allocator) = 0;

        virtual const std::type_info& onTypeInfo() const = 0;

    public:
        template <typename EventT>
        static Event& copyConstruct(const EventT& ev, Allocator& allocator)
        {
            void* mem = allocator.allocate( sizeof(EventT) );
            EventT* pev = new (mem) EventT(ev);
            return *(pev);
        }

        template <typename EventT>
        static void destruct(EventT& ev, Allocator& allocator)
        {
            ev.~EventT();
            allocator.deallocate(&ev, sizeof(EventT));
        }
};

template <typename T>
class BasicEvent : public Event
{
    protected:
        BasicEvent()
        {}

        virtual const std::type_info& onTypeInfo() const
        { return typeid(T); }

        virtual Event& onClone(Allocator& allocator) const
        {
            void* pEvent = allocator.allocate(sizeof(T));
            return *(new (pEvent)T(*static_cast<const T*>(this)));
        }

        virtual void onDestroy(Allocator& allocator)
        {
            this->~BasicEvent();
            allocator.deallocate(this, sizeof(T));
        }
};

} // namespace Pt

#endif