Core: Added Listenable class (Made class Listener system generic)

Former-commit-id: 3baed32d6720c6455f50af51f262292ece9943fa

include/Nazara/Core/Listenable.hpp

@@ -0,0 +1,33 @@
+// Copyright (C) 2015 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_LISTENABLE_HPP
+#define NAZARA_LISTENABLE_HPP
+
+#include <Nazara/Prerequesites.hpp>
+#include <unordered_map>
+
+template<typename Base>
+class NzListenable
+{
+	public:
+		NzListenable();
+		~NzListenable() = default;
+
+		template<typename L> void AddListener(L* listener, void* userdata = nullptr) const;
+		template<typename L> void RemoveListener(L* listener) const;
+
+		template<typename F, typename... Args> void Notify(F callback, Args&&... args);
+		template<typename F> void NotifyRelease(F callback);
+
+	private:
+		mutable std::unordered_map<void*, void*> m_listeners;
+		bool m_listenersLocked;
+};
+
+#include <Nazara/Core/Listenable.inl>
+
+#endif // NAZARA_LISTENABLE_HPP

include/Nazara/Core/Listenable.inl

@@ -0,0 +1,68 @@
+// Copyright (C) 2015 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/Debug.hpp>
+
+template<typename Base>
+NzListenable<Base>::NzListenable() :
+m_listenersLocked(false)
+{
+}
+
+template<typename Base>
+template<typename L>
+void NzListenable<Base>::AddListener(L* listener, void* userdata) const
+{
+	static_assert(std::is_base_of<typename Base::Listener, L>::value, "`listener` does not derive from a Listener");
+
+	if (!m_listenersLocked)
+		m_listeners.insert(std::make_pair(listener, userdata));
+}
+
+template<typename Base>
+template<typename L>
+void NzListenable<Base>::RemoveListener(L* listener) const
+{
+	static_assert(std::is_base_of<typename Base::Listener, L>::value, "`listener` does not derive from a Listener");
+
+	if (!m_listenersLocked)
+		m_listeners.erase(listener);
+}
+
+template<typename Base>
+template<typename F, typename... Args>
+void NzListenable<Base>::Notify(F callback, Args&&... args)
+{
+	using Listener = typename Base::Listener;
+
+	m_listenersLocked = true;
+
+	auto it = m_listeners.begin();
+	while (it != m_listeners.end())
+	{
+		Listener* listener = static_cast<Listener*>(it->first);
+		if (!(listener->*callback)(static_cast<Base*>(this), std::forward<Args>(args)..., it->second))
+			m_listeners.erase(it++);
+		else
+			++it;
+	}
+
+	m_listenersLocked = false;
+}
+
+template<typename Base>
+template<typename F>
+void NzListenable<Base>::NotifyRelease(F callback)
+{
+	using Listener = typename Base::Listener;
+
+	m_listenersLocked = true;
+	for (auto& pair : m_listeners)
+	{
+		Listener* listener = static_cast<Listener*>(pair.first);
+		(listener->*callback)(static_cast<Base*>(this), pair.second);
+	}
+}
+
+#include <Nazara/Core/DebugOff.hpp>