snapdialog.cpp

C++编程100例

// SnapDialog.cpp : implementation file
//

#include "stdafx.h"
#include "SnapDlg.h"
#include "SnapDialog.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CSnapDialog dialog


CSnapDialog::CSnapDialog(UINT IDD, CWnd* pParent /*=NULL*/)
	: CDialog(IDD, pParent)
{
	//{{AFX_DATA_INIT(CSnapDialog)
	m_nEdgeSnapGap = 50;
	//}}AFX_DATA_INIT
}

void CSnapDialog::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CSnapDialog)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CSnapDialog, CDialog)
	//{{AFX_MSG_MAP(CSnapDialog)
		// NOTE: the ClassWizard will add message map macros here
		ON_WM_WINDOWPOSCHANGING()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CSnapDialog message handlers

void CSnapDialog::OnWindowPosChanging( WINDOWPOS* lpwndpos )
{
	RECT rcScrn;
	SystemParametersInfo (SPI_GETWORKAREA, 0, &rcScrn, 0);

	// Snap X axis
	if (abs(lpwndpos->x - rcScrn.left) <= m_nEdgeSnapGap)
		lpwndpos->x = rcScrn.left;
	else if (abs(lpwndpos->x + lpwndpos->cx - rcScrn.right) <= m_nEdgeSnapGap)
	lpwndpos->x = rcScrn.right - lpwndpos->cx;

	// Snap Y axis
	if (abs(lpwndpos->y - rcScrn.top) <= m_nEdgeSnapGap)
		lpwndpos->y = rcScrn.top;
	else if (abs(lpwndpos->y + lpwndpos->cy - rcScrn.bottom) <= m_nEdgeSnapGap)
		lpwndpos->y = rcScrn.bottom - lpwndpos->cy;
}