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struct SNAPINFO
{
	enum { MAXDELTA = (1<<30) };

	DWORD	snapWidth;

	RECT	rold;
	RECT	rnew;
	RECT	rdelta;

	RECT	rout;

	void	Init(RECT const & oldRect, RECT const & newRect, DWORD snapwidth);
	void	Init(RECT const & r, DWORD snapWidth, bool moveOnly = false);
	void	SnapHLine(long y);		// snap to a horizontal line
	void	SnapVLine(long x);		// snap to a vertical line

	RECT &	EndSnap();  // final coords in rout
};





class CMDISnapper  
{
public:

protected:
	DWORD				m_snapWidth;

	// helper for "move" coordinates
	CWnd *				m_wndMoving; 
	POINT				m_mouseStart;
	POINT				m_rectStart;

public:
			 CMDISnapper(DWORD snapWidth = 8);
	virtual ~CMDISnapper();

	void	SetSnapWidth(DWORD snapWidth);
	DWORD	GetSnapWidth() const		{ return m_snapWidth; }

	LRESULT	OnMessage(CWnd * wnd, UINT msg, WPARAM wp, LPARAM lp);

  	void	Sizing(CWnd * wnd, RECT & rnew);

	void	OnEnterSizeMove(CWnd * wnd);
	void	OnExitSizeMove();
	void	OnSizing(CWnd * wnd, WPARAM edge, LPRECT newrect);
	void	OnMoving(CWnd * wnd, WPARAM edge, LPRECT newrect);



};