Event.h

#pragma once
#include "Core/Engine/ECS/Common.h"
 
namespace Nui::ECS
{
    namespace Internal
    {
        class EventSubscriberBase
        {
        public:
            virtual ~EventSubscriberBase() = default;
        };
    }
 
    template <typename T>
    class EventSubscriber : public Internal::EventSubscriberBase
    {
    public:
        virtual ~EventSubscriber() = default;
 
        virtual void OnEvent(Context* context, const T& event) = 0;
    };
 
    namespace Events
    {
        struct OnEntityCreate
        {
            Entity* Entity;
        };
 
        struct OnEntityDestroy
        {
            Entity* Entity;
        };
 
        template <typename T>
        struct OnComponentAdd
        {
            Entity* Entity;
 
            ComponentHandle<T> Component;
        };
 
        template <typename T>
        struct OnComponentRemove
        {
            Entity* Entity;
 
            ComponentHandle<T> Component;
        };
    }
}
 
// Use this macro to inherit from Nui::ECS::EventSubscriber<Type>
#define NUI_EVENT_SUBSCRIBER(Type) public ECS::EventSubscriber<Type>
 
// Use this macro to declare an event function in header files (needs use of NUI_EVENT_SUBSCRIBER macro with same type)
#define NUI_DECLARE_EVENT(Type) virtual void OnEvent(Nui::ECS::Context* ctx, const Type& event) override
 
// Use this macro to define an event function in source files (needs use of NUI_DECLARE_EVENT macro)
#define NUI_DEFINE_EVENT(Class, Type) void Class::OnEvent(Nui::ECS::Context* ctx, const Type& event)
 
// Use this macro to subscribe to an event function (needs use of NUI_DECLARE_EVENT & NUI_EVENT_SUBSCRIBER macro)
#define NUI_SUBSCRIBE_EVENT(ECSContext, Type) ECSContext->SubscribeEvent<Type>(this)
 
// Use this macro to unsubscribe from an event function (needs use of NUI_DECLARE_EVENT & NUI_EVENT_SUBSCRIBER macro)
#define NUI_UNSUBSCRIBE_EVENT(ECSContext, Type) ECSContext->UnsubscribeEvent<Type>(this)
 
// Use this macro to unsubscribe from all events - use in destructor/shutdown functions
#define NUI_UNSUBSCRIBE_EVENTS_ALL(ECSContext) ECSContext->UnsubscribeAll(this)