1 files changed, 91 insertions, 0 deletions
diff --git a/src/cru_event.h b/src/cru_event.h
new file mode 100644
index 00000000..d0a7eb82
--- /dev/null
+++ b/src/cru_event.h
@@ -0,0 +1,91 @@
+#pragma once
+
+#include <type_traits>
+#include <list>
+#include <memory>
+#include <algorithm>
+
+#include "base.h"
+
+namespace cru {
+	//Base class of all event args.
+	class BasicEventArgs : public Object
+	{
+	public:
+		explicit BasicEventArgs(Object* sender)
+            : sender_(sender)
+		{
+		    
+		}
+	    BasicEventArgs(const BasicEventArgs& other) = default;
+	    BasicEventArgs(BasicEventArgs&& other) = default;
+	    BasicEventArgs& operator=(const BasicEventArgs& other) = default;
+	    BasicEventArgs& operator=(BasicEventArgs&& other) = default;
+		~BasicEventArgs() override = default;
+
+		//Get the sender of the event.
+		Object* GetSender() const
+		{
+            return sender_;
+		}
+
+	private:
+		Object* sender_;
+	};
+
+
+	//A non-copyable non-movable Event class.
+	//It stores a list of event handlers.
+	//TArgsType must be subclass of BasicEventArgs.
+    template<typename TArgsType>
+    class Event
+	{
+    public:
+		static_assert(std::is_base_of_v<BasicEventArgs, TArgsType>,
+			"TArgsType must be subclass of BasicEventArgs.");
+
+
+        using ArgsType = TArgsType;
+        using EventHandler = Function<void(ArgsType&)>;
+        using EventHandlerPtr = std::shared_ptr<EventHandler>;
+
+        Event() = default;
+        Event(const Event&) = delete;
+        Event& operator = (const Event&) = delete;
+        Event(Event&&) = delete;
+        Event& operator = (Event&&) = delete;
+        ~Event() = default;
+
+        //Create a EventHandlerPtr from the given handler,
+        //add it to list and return it.
+		EventHandlerPtr AddHandler(EventHandler&& handler)
+		{
+			EventHandlerPtr ptr = std::make_shared<EventHandler>(std::move(handler));
+			handlers_.push_back(ptr);
+			return ptr;
+		}
+
+		void AddHandler(EventHandlerPtr handler) {
+			handlers_.push_back(handler);
+		}
+
+		void RemoveHandler(EventHandlerPtr handler) {
+			auto find_result = std::find(handlers_.cbegin(), handlers_.cend(), handler);
+			if (find_result != handlers_.cend())
+				handlers_.erase(find_result);
+		}
+
+		void Raise(ArgsType& args) {
+			for (auto ptr : handlers_)
+				(*ptr)(args);
+		}
+
+        bool IsNoHandler() const
+		{
+		    return handlers_.empty();
+		}
+
+    private:
+        std::list<EventHandlerPtr> handlers_;
+    };
+}