subclass.h

来自「3D reconstruction, medical image process」· C头文件 代码 · 共 52 行

////////////////////////////////////////////////////////////////
// RxSubclassWnd Copyright 1996 Microsoft Systems Journal. 
// If this code works, it was written by Paul DiLascia.
// If not, I don't know who wrote it.
//
#ifndef _MSGHOOK_H
#define _MSGHOOK_H

//////////////////
// Generic class to hook messages on behalf of a CWnd.
// Once hooked, all messages go to RxSubclassWnd::WindowProc before going
// to the window. Specific subclasses can trap messages and do something.
//
// To use:
//
// * Derive a class from RxSubclassWnd.
//
// * Override RxSubclassWnd::WindowProc to handle messages. Make sure you call
//   RxSubclassWnd::WindowProc if you don't handle the message, or your window will
//   never get messages. If you write seperate message handlers, you can call
//   Default() to pass the message to the window.
//
// * Instantiate your derived class somewhere and call HookWindow(pWnd)
//   to hook your window, AFTER it has been created.
//	 To unhook before the window is destroyed, call HookWindow(NULL).
//
class RxSubclassWnd : public CObject 
{
protected:
	DECLARE_DYNAMIC(RxSubclassWnd);
	CWnd*			m_pWndHooked;		// the window hooked
	WNDPROC			m_pOldWndProc;		// ..and original window proc
	RxSubclassWnd*	m_pNext;			// next in chain of hooks for this window

	// Override this to handle messages in specific handlers
	virtual LRESULT WindowProc(UINT msg, WPARAM wp, LPARAM lp);
	LRESULT Default();					// call this at the end of handler fns

public:
	RxSubclassWnd();
	~RxSubclassWnd();

	// Hook a window. Hook(NULL) to unhook (automatic on WM_NCDESTROY)
	BOOL	HookWindow(CWnd* pRealWnd);
	BOOL	IsHooked()	{ return (m_pWndHooked != NULL); }

	friend LRESULT CALLBACK HookWndProc(HWND, UINT, WPARAM, LPARAM);
	friend class RxSubclassWndMap;
};

#endif