add EventListener::ShouldHandle function

src/kiwano/event/Event.h

@@ -54,7 +54,7 @@ public:
 
     /// \~chinese
     /// @brief 判断事件类型
-    /// @return 是否是指定事件类型
+    /// @return 事件类型相同返回true，否则返回false
     template <typename _Ty>
     bool IsType() const;
 
@@ -75,19 +75,20 @@ private:
 };
 
 /// \~chinese
-/// @brief 事件特性：判断指定类型是否是事件
+/// @brief 事件特性：判断是否是事件
 template <typename _Ty>
-struct IsEvent : public std::bool_constant<std::is_base_of<Event, _Ty>::value || std::is_same<Event, _Ty>::value>
+struct IsBaseOfEvent : public std::bool_constant<std::is_base_of<Event, _Ty>::value || std::is_same<Event, _Ty>::value>
 {
 };
 
 /// \~chinese
-/// @brief 事件特性：判断一个事件能否安全转换到另一事件类型
-template <typename _Ty, typename = typename std::enable_if<IsEvent<_Ty>::value, int>::type>
-struct IsEventType
+/// @brief 事件特性：判断事件类型是否相同
+template <typename _Ty>
+struct IsSameEventType
 {
     inline bool operator()(const Event* evt) const
     {
+        static_assert(kiwano::IsBaseOfEvent<_Ty>::value, "_Ty is not an event type.");
         return evt->GetType() == KGE_EVENT(_Ty);
     }
 };
@@ -102,8 +103,8 @@ inline const EventType& Event::GetType() const
 template <typename _Ty>
 inline bool Event::IsType() const
 {
-    static_assert(kiwano::IsEvent<_Ty>::value, "_Ty is not an event type.");
-    return kiwano::IsEventType<_Ty>()(this);
+    static_assert(kiwano::IsBaseOfEvent<_Ty>::value, "_Ty is not an event type.");
+    return IsSameEventType<_Ty>()(this);
 }
 
 template <typename _Ty>

src/kiwano/event/EventDispatcher.h

@@ -59,7 +59,7 @@ public:
     template <typename _EventTy>
     EventListener* AddListener(EventListener::Callback callback)
     {
-        static_assert(kiwano::IsEvent<_EventTy>::value, "_EventTy is not an event type.");
+        static_assert(kiwano::IsBaseOfEvent<_EventTy>::value, "_EventTy is not an event type.");
         return AddListener(KGE_EVENT(_EventTy), callback);
     }
 
@@ -71,7 +71,7 @@ public:
     template <typename _EventTy>
     EventListener* AddListener(const String& name, EventListener::Callback callback)
     {
-        static_assert(kiwano::IsEvent<_EventTy>::value, "_EventTy is not an event type.");
+        static_assert(kiwano::IsBaseOfEvent<_EventTy>::value, "_EventTy is not an event type.");
         return AddListener(name, KGE_EVENT(_EventTy), callback);
     }
 

src/kiwano/event/EventListener.cpp

@@ -58,4 +58,12 @@ EventListener::EventListener()
 
 EventListener::~EventListener() {}
 
+void EventListener::Receive(Event* evt)
+{
+    if (ShouldHandle(evt) && callback_)
+    {
+        callback_(evt);
+    }
+}
+
 }  // namespace kiwano

src/kiwano/event/EventListener.h

@@ -67,7 +67,7 @@ public:
     template <typename _EventTy>
     static inline EventListenerPtr Create(const Callback& callback)
     {
-        static_assert(kiwano::IsEvent<_EventTy>::value, "_EventTy is not an event type.");
+        static_assert(kiwano::IsBaseOfEvent<_EventTy>::value, "_EventTy is not an event type.");
         return EventListener::Create(KGE_EVENT(_EventTy), callback);
     }
 
@@ -79,7 +79,7 @@ public:
     template <typename _EventTy>
     static inline EventListenerPtr Create(const String& name, const Callback& callback)
     {
-        static_assert(kiwano::IsEvent<_EventTy>::value, "_EventTy is not an event type.");
+        static_assert(kiwano::IsBaseOfEvent<_EventTy>::value, "_EventTy is not an event type.");
         return EventListener::Create(name, KGE_EVENT(_EventTy), callback);
     }
 
@@ -132,12 +132,17 @@ public:
     /// @brief 设置监听的事件类型
     void SetEventType(const EventType& type);
 
+    /// \~chinese
+    /// @brief ÅжÏÊÇ·ñ´¦Àíʼþ
+    virtual bool ShouldHandle(Event* evt) const;
+
     /// \~chinese
     /// @brief 设置监听的事件类型
     /// @tparam _EventTy 事件类型
-    template <typename _EventTy, typename = typename std::enable_if<IsEvent<_EventTy>::value, int>::type>
+    template <typename _EventTy>
     inline void SetEventType()
     {
+        static_assert(kiwano::IsBaseOfEvent<_EventTy>::value, "_EventTy is not an event type.");
         SetEventType(KGE_EVENT(_EventTy));
     }
 
@@ -208,13 +213,13 @@ inline void EventListener::SetEventType(const EventType& type)
     type_ = type;
 }
 
-inline void EventListener::Receive(Event* evt)
+inline bool EventListener::ShouldHandle(Event* evt) const
 {
-    KGE_ASSERT(evt != nullptr);
-
-    if (type_ == evt->GetType() && callback_)
+    if (evt)
     {
-        callback_(evt);
+        return evt->GetType() == type_;
     }
+    return false;
 }
+
 }  // namespace kiwano

src/kiwano/event/KeyEvent.h

@@ -72,10 +72,8 @@ public:
     KeyCharEvent();
 };
 
-/** @} */
-
 template <>
-struct IsEventType<KeyEvent>
+struct IsSameEventType<KeyEvent>
 {
     inline bool operator()(const Event* evt) const
     {
@@ -84,4 +82,6 @@ struct IsEventType<KeyEvent>
     }
 };
 
+/** @} */
+
 }  // namespace kiwano

src/kiwano/event/MouseEvent.h

@@ -113,10 +113,8 @@ public:
     MouseWheelEvent();
 };
 
-/** @} */
-
 template <>
-struct IsEventType<MouseEvent>
+struct IsSameEventType<MouseEvent>
 {
     inline bool operator()(const Event* evt) const
     {
@@ -127,4 +125,6 @@ struct IsEventType<MouseEvent>
     }
 };
 
+/** @} */
+
 }  // namespace kiwano

src/kiwano/event/WindowEvent.h

@@ -93,10 +93,8 @@ public:
     WindowClosedEvent();
 };
 
-/** @} */
-
 template <>
-struct IsEventType<WindowEvent>
+struct IsSameEventType<WindowEvent>
 {
     inline bool operator()(const Event* evt) const
     {
@@ -107,4 +105,6 @@ struct IsEventType<WindowEvent>
     }
 };
 
+/** @} */
+
 }  // namespace kiwano