DirectUI消息循环的简单封装

 

一.真窗体和假窗体

首先在DirectWindow内部创建一个真窗体(基于WTL),可以接收消息

class CMessageWindow : public CWindowImpl< CMessageWindow >
{
public:
CMessageWindow();
~CMessageWindow();
BEGIN_MSG_MAP( CMessageWindow )
MESSAGE_RANGE_HANDLER( 0, 0xFFFF, HandleMessage )
END_MSG_MAP()
}

然后在在HandleMessage 处理消息





二.通过MessageDispatcher转发消息





三.组装给上层比较容易理解的数据结构





这样上层就捕捉不到WM_LBUTTONUP消息,而变成自己封装的DirectUI_LButtonUp消息了

全部伪代码

class EventArg
{
public:
int nId;
};

class MouseEventArg:public EventArg
{
public:
int nX;
int nY;
int uKeyFlags;
};

class MessageDispatcher
{
MessageDispatcher(DirectWindow *pWindow)
{
m_pWindow=pWindow;
}

void DispatcherLButtonUp(POINT pt,UINT uKeyFlags,BOOL *pbHandled)
{
MouseEventArg arg;
arg.nId=DirectUI_LButtonUp;
arg.nX=pt.x;
arg.nY=pt.y;
m_pWindow->OnMessage(&arg);
}

private:
DirectWindow *m_pWindow;
};

class CMessageWindow : public CWindowImpl< CMessageWindow >
{
public:
CMessageWindow();
~CMessageWindow();
BEGIN_MSG_MAP( CMessageWindow )
MESSAGE_RANGE_HANDLER( 0, 0xFFFF, HandleMessage )
END_MSG_MAP()

virtual    LRESULT            HandleMessage( UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled );

private:
MessageDispatcher *m_pMessageDispatcher;
}

void CMessageWindow::OnLButtonUp( HWND hWnd, int nX, int nY, UINT uKeyFlags, BOOL& bHandled )
{
POINT pt = {nX, nY};
::ClientToScreen(hWnd, &pt);

m_pMessageDispatcher->DispatcherLButtonUp(pt, uKeyFlags, &bHandled)
}

class IElement;

class DirectWindow
{
HRESULT OnMessage( IElement *pElement, EventArg *pArg, BOOL* pbHandled);
private:
CMessageWindow *m_pMessageWindow;
};