Posted on 2008-10-10 21:12
Condor 閱讀(1376)
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看到Fox發表關于
成員函數的消息映射的文章，也忍不住發表的一點自己的觀點，希望對大家有所幫助。
其實也就是COMMAND模式的簡單實現，看代碼吧。
1. XGUIEventHandlerPointer.h
namespace XGUI
{
class EventHandlerSlot
{
public:
virtual ~EventHandlerSlot() {};
virtual void execute(const EventArgs& args) = 0;
virtual void* getClass() = 0;
};
template<typename T>
class EventHandlerPointer :
public EventHandlerSlot
{
public:
typedef void (T::*EventHandler)(const EventArgs&);
public:
EventHandlerPointer() :
d_undefined(true),
d_object(NULL)
{}
EventHandlerPointer(EventHandler func, T* obj) :
d_function(func),
d_object(obj),
d_undefined(false)
{}
virtual ~EventHandlerPointer() {}
void execute(const EventArgs& args)
{
if(!d_undefined)
(d_object->*d_function)(args);
}
void* getClass()
{
return static_cast<void*>(d_object);
}
protected:
EventHandler d_function;
T* d_object;
bool d_undefined;
};
}
2. XGUIWidget.h
namespace XGUI
{
//
class Widget
{
public:
template<typename T> void addWidgetEventHandler(WidgetEvent EVENT, void (T::*function)(const EventArgs&), T* obj)
{
mWidgetEventHandlers[EVENT].push_back(new EventHandlerPointer<T>(function,obj));
}
void addWidgetEventHandler(WidgetEvent EVENT, EventHandlerSlot* function)
{
mWidgetEventHandlers[EVENT].push_back(new EventHandlerPointer<T>(function,obj));
}
bool Widget::fireWidgetEvent(WidgetEvent EVENT, EventArgs& args)
{
// If there are no User defined event handlers we are done.
if(mWidgetEventHandlers[EVENT].empty())
return false;
// Execute registered handlers
std::vector<EventHandlerSlot*>* userEventHandlers = &(mWidgetEventHandlers[EVENT]);
for(std::vector<EventHandlerSlot*>::iterator it = userEventHandlers->begin(); it != userEventHandlers->end(); ++it )
(*it)->execute(args);
return true;
}
// .
};
}
以上只為部分代碼。