// This file is part of w3c - wwwcam.

// w3c is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// w3c 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 for more details.

// You should have received a copy of the GNU General Public License
// along with w3c. If not, see <http://www.gnu.org/licenses/>.
//
// (C) Copyright 2015 by Sebastian Büttner <sebastian.buettner@iem.thm.de>

#ifndef HELPER_EVENT_H
#define HELPER_EVENT_H

#include <forward_list>

template<typename... event_arg_types>
class event;

template<typename... event_arg_types>
class event_handlers {
    friend class event;
public:
    using handler_type = void()(event_arg_types...);

    event_handlers& operator+=(handler_type &&handler)
    {
        add(std::forward<handler_type>(handler));
    }

    event_handlers& add(handler_type &&handler)
    {
        m_handlers.push_front(handler);
    }

private:
    std::forward_list<handler_type> m_handlers;
};

template<typename... event_arg_types>
class event {
public:
    void operator()(event_arg_types... event_args)
    {
        for (auto handler : m_handlers.m_handlers)
            handler(std::forward<event_arg_types...>(event_args...));
    }

    event_handlers<event_arg_types...> handlers() const
    {
        return m_handlers;
    }

private:
    event_handlers<event_arg_types...> m_handlers;
};

#endif