Event.h

// Copyright (c) 2016-2018 Kiwano - Nomango
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
 
#pragma once
#include <kiwano/base/RefObject.h>
#include <kiwano/base/RefPtr.h>
#include <kiwano/event/EventType.h>
#include <kiwano/math/Math.h>
 
namespace kiwano
{
 
class KGE_API Event : public RefObject
{
public:
    Event(const EventType& type);
 
    virtual ~Event();
 
    const EventType& GetType() const;
 
    template <typename _Ty>
    bool IsType() const;
 
    template <typename _Ty>
    const _Ty* Cast() const;
 
    template <typename _Ty>
    _Ty* Cast();
 
private:
    const EventType type_;
};
 
template <typename _Ty>
struct IsSameEventType
{
    inline bool operator()(const Event* evt) const
    {
        static_assert(std::is_base_of<Event, _Ty>::value, "_Ty is not an event type.");
        return evt->GetType() == KGE_EVENT(_Ty);
    }
};
 
inline const EventType& Event::GetType() const
{
    return type_;
}
 
template <typename _Ty>
inline bool Event::IsType() const
{
    static_assert(std::is_base_of<Event, _Ty>::value, "_Ty is not an event type.");
    return IsSameEventType<_Ty>()(this);
}
 
template <typename _Ty>
inline const _Ty* Event::Cast() const
{
    return const_cast<Event*>(this)->Cast<_Ty>();
}
 
template <typename _Ty>
inline _Ty* Event::Cast()
{
    if (!this->IsType<_Ty>())
        return nullptr;
    return dynamic_cast<_Ty*>(this);
}
 
}  // namespace kiwano