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- /*
- * Copyright (C) 2021 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code 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.
- *
- * Antkeeper source code 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 Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #ifndef ANTKEEPER_EVENT_HANDLER_HPP
- #define ANTKEEPER_EVENT_HANDLER_HPP
-
- #include "event.hpp"
- #include <type_traits>
-
- class event_dispatcher;
-
- /**
- * Abstract base class for event handlers.
- */
- class event_handler_base
- {
- private:
- friend class event_dispatcher;
-
- /**
- * Receives an event, casts it to its derived event type, then handles it.
- *
- * @param event Received event.
- */
- virtual void route_event(const event_base& event) = 0;
- };
-
- /**
- * Templates abstract base class for event handlers.
- *
- * @tparam Event type.
- */
- template <typename T>
- class event_handler: public event_handler_base
- {
- public:
- static_assert(std::is_base_of<event_base, T>::value, "T must be a descendant of event_base.");
-
- /// Returns the unique event type identifier for the event type handled by this event handler.
- const std::size_t get_handled_event_type_id() const;
-
- /**
- * Handles an event of type T.
- *
- * @param event Event to handle.
- */
- virtual void handle_event(const T& event) = 0;
-
- private:
- /// @copydoc event_handler_base::route_event()
- virtual void route_event(const event_base& event) final;
- };
-
- template <typename T>
- inline const std::size_t event_handler<T>::get_handled_event_type_id() const
- {
- return T::event_type_id;
- }
-
- template <typename T>
- void event_handler<T>::route_event(const event_base& event)
- {
- handle_event(static_cast<const T&>(event));
- }
-
- #endif // ANTKEEPER_EVENT_HANDLER_HPP
-
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