zoomview.cpp

这是一个能简单处理测量里面导线网平差的程序

   FUNCTION: SetZoomMode
   PURPOSE : Put the view into the specified zoom mode
---------------------------------------------------------------------------*/
void CZoomView::SetZoomMode (
	ZoomMode_ zoomMode)
{
	ASSERT(m_nMapMode == MM_ANISOTROPIC);
	if (zoomMode != m_zoomMode) {
		m_zoomMode = zoomMode;
		// Force cursor change now
		OnSetCursor(NULL, HTCLIENT, 0);
	}
} // SetZoomMode


/*---------------------------------------------------------------------------
   FUNCTION: CenterOnLogicalPoint
   PURPOSE : Same as CScrollView::CenterOnPoint, but for logical coordinates
---------------------------------------------------------------------------*/
void CZoomView::CenterOnLogicalPoint(CPoint pt)
{
	// Convert the point to device coordinates
	ViewLPtoDP(&pt);
	// Account for scroll bar position
	ClientToDevice(pt);
	// Use CScrollView's function for device coordinates
	CScrollView::CenterOnPoint(pt);
} // CenterOnLogicalPoint

/*---------------------------------------------------------------------------
   FUNCTION: GetLogicalCenterPoint
   PURPOSE : Get the center of screen in logical coordinates
---------------------------------------------------------------------------*/
CPoint CZoomView::GetLogicalCenterPoint (void)  // Point in logical units
{
	CPoint pt;
	CRect rect;
	// Get the center of screen
	GetClientRect(&rect);
	pt.x = (rect.Width()  / 2);
	pt.y = (rect.Height() / 2);

	// Convert the point to logical coordinates
	ViewDPtoLP(&pt);
	return pt;
} // GetLogicalCenterPoint

/*---------------------------------------------------------------------------
   FUNCTION: DrawBox
   PURPOSE : Draw a box - XOR if want to erase
---------------------------------------------------------------------------*/
void CZoomView::DrawBox (
	CDC   &dc,
	CRect &rect,
	BOOL  xor)
{
	CPen pen;
	// Save the device context
	dc.SaveDC();
	if (xor) {
		dc.SetROP2(R2_NOTXORPEN);
		pen.CreatePen(PS_DASH,  0, RGB(0, 0, 0)); // 0 width = 1 device unit
	} else {
		pen.CreatePen(PS_SOLID, 0, RGB(0, 0, 0)); // 0 width = 1 device unit
	}
	dc.SelectObject(&pen);
	// Draw the rect with lines (eliminate rect middle fill)
	dc.MoveTo(rect.left,  rect.top);
	dc.LineTo(rect.right, rect.top);
	dc.LineTo(rect.right, rect.bottom);
	dc.LineTo(rect.left,  rect.bottom);
	dc.LineTo(rect.left,  rect.top);
	// Clean up
	dc.RestoreDC(-1);
} // DrawBox

/*---------------------------------------------------------------------------
   FUNCTION: DrawLine
   PURPOSE : Draw a line - XOR to erase
---------------------------------------------------------------------------*/
void CZoomView::DrawLine (
	CDC &dc,
	const int &x1, // Logical units
	const int &y1,
	const int &x2,
	const int &y2,
	BOOL      xor)
{	
	CPen pen;
	// Save the device context
	dc.SaveDC();
	if (xor) {
		dc.SetROP2(R2_NOTXORPEN);
		pen.CreatePen(PS_DASH,  0, RGB(0, 0, 0)); // 0 width = 1 device unit
	} else {
		pen.CreatePen(PS_SOLID, 0, RGB(0, 0, 0)); // 0 width = 1 device unit
	}
	dc.SelectObject(&pen);

	// Draw the line
	dc.MoveTo(x1, y1);
	dc.LineTo(x2, y2);
	// Clean up
	dc.RestoreDC(-1);
} // DrawLine

/*---------------------------------------------------------------------------
   FUNCTION: OnLButtonDown
   PURPOSE : Handle the left mouse click
---------------------------------------------------------------------------*/
void CZoomView::OnLButtonDown(
	UINT nFlags, 
	CPoint point)
{
	// Pass the message along
	CScrollView::OnLButtonDown(nFlags, point);

	switch (m_zoomMode) {
		case MODE_ZOOMIN:
			// Capture the mouse for zooming in
			m_bCaptured = TRUE;
			SetCapture();
			// Save the mouse down point for XOR rect
			ViewDPtoLP(&point);
			m_ptDragRect.SetRect(point.x, point.y, point.x, point.y);
			// Set the cursor to the cross hair
			::SetCursor(::LoadCursor(NULL, MAKEINTRESOURCE(IDC_CROSS)));
			break;

		default:
			// Do nothing.
			break;
	}
} // OnLButtonDown

/*---------------------------------------------------------------------------
   FUNCTION: OnMouseMove
   PURPOSE : Handle the mouse movement
---------------------------------------------------------------------------*/
void CZoomView::OnMouseMove(UINT nFlags, CPoint point)
{
	// Pass the message along
	CScrollView::OnMouseMove(nFlags, point);

	if (m_bCaptured) {
		// Get the Device Context
		CClientDC dc(this);
		OnPrepareDC(&dc);
	
		switch (m_zoomMode) {
			case MODE_ZOOMIN:
				// Draw the drag-rect
				// Erase last rect
				DrawBox(dc, m_ptDragRect);
				// Draw new rect
				dc.DPtoLP(&point);
				m_ptDragRect.BottomRight() = point;
				DrawBox(dc, m_ptDragRect);
				break;

			default:
				// Do nothing.
				break;
		}
	}
} // OnMouseMove

/*---------------------------------------------------------------------------
   FUNCTION: OnLButtonUp
   PURPOSE : Handle the left mouse release
---------------------------------------------------------------------------*/
void CZoomView::OnLButtonUp (
	UINT nFlags, 
	CPoint point)
{
	// Pass the message along
	CScrollView::OnLButtonUp(nFlags, point);
	
	switch (m_zoomMode) {
		case MODE_ZOOMIN:
			// Uncapture the mouse?
			if (m_bCaptured) {
				m_bCaptured = FALSE;
				ReleaseCapture();
				// Set back the cross cursor to the Z
				::SetCursor(m_hZoomCursor);
				// Get the Device Context
				CClientDC dc(this);
				OnPrepareDC(&dc);
				// Erase the bounding box
				DrawBox(dc, m_ptDragRect);
				// Now Zoom in on logical rectangle
				DoZoomIn(m_ptDragRect);
			}
			break;

		case MODE_ZOOMOUT:
			ViewDPtoLP(&point);
			DoZoomOut(&point);
			break;

		default:
			// Do nothing.
			break;
	}
} // OnLButtonUp

/*---------------------------------------------------------------------------
   FUNCTION: OnRButtonDown
   PURPOSE : Handle the right mouse click - CANCELS CURRENT ZOOM MODE OR DRAG
---------------------------------------------------------------------------*/
void CZoomView::OnRButtonDown(UINT nFlags, CPoint point)
{
	CScrollView::OnRButtonDown(nFlags, point);

	// See if currently captured
	if (m_bCaptured) {
		// Maintain current mode, just stop current drag
		m_bCaptured = FALSE;
		ReleaseCapture();
		// Get the Device Context
		CClientDC dc(this);
		OnPrepareDC(&dc);

		switch (m_zoomMode) {
			case MODE_ZOOMIN:
				// Erase last rect
				DrawBox(dc, m_ptDragRect);
				break;

			default:
				// Do nothing.
				break;
		}
	} else {
		// Cancel current mode
		m_zoomMode = MODE_ZOOMOFF;
	}
} // OnRButtonDown

/*---------------------------------------------------------------------------
   FUNCTION: OnSetCursor
   PURPOSE : Set the cursor depending on the zoom mode
---------------------------------------------------------------------------*/
BOOL CZoomView::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
	if (nHitTest != HTCLIENT)
		return CScrollView::OnSetCursor(pWnd, nHitTest, message);

	switch (m_zoomMode) {
		case MODE_ZOOMOFF:
			::SetCursor(::LoadCursor(NULL, IDC_ARROW));
			break;

		default:
			// All other zoom modes
			::SetCursor(m_hZoomCursor);
			break;
	} // Zoom mode select

	return TRUE;
} // OnSetCursor

/*---------------------------------------------------------------------------
   FUNCTION: ViewDPtoLP
   PURPOSE : Same as DPtoLP, but gets the Client DC for the view
---------------------------------------------------------------------------*/
void CZoomView::ViewDPtoLP (
	LPPOINT lpPoints,
	int     nCount)
{
	// Convert to logical units
	// Called from View when no DC is available
	ASSERT(m_nMapMode > 0); // must be set
	CWindowDC dc(this);
	OnPrepareDC(&dc);
	dc.DPtoLP(lpPoints, nCount);
} // ViewDPtoLP

/*---------------------------------------------------------------------------
   FUNCTION: ViewLPtoDP
   PURPOSE : Same as LPtoDP, but gets the Client DC for the view
---------------------------------------------------------------------------*/
void CZoomView::ViewLPtoDP (
	LPPOINT lpPoints,
	int     nCount)
{
	// Convert to logical units
	// Called from View when no DC is available
	ASSERT(m_nMapMode > 0); // must be set
	CWindowDC dc(this);
	OnPrepareDC(&dc);
	dc.LPtoDP(lpPoints, nCount);
} // ViewLPtoDP

/*---------------------------------------------------------------------------
   FUNCTION: ClientToDevice
   PURPOSE : Convert from Client coordinates to relative Device coordinates
---------------------------------------------------------------------------*/
void CZoomView::ClientToDevice (
	CPoint &point)
{
	// Need to account for scrollbar position
	CPoint scrollPt = GetDeviceScrollPosition();
	point.x += scrollPt.x;
	point.y += scrollPt.y;
} // ClientToDevice

/*---------------------------------------------------------------------------
   FUNCTION: NormalizeRect
   PURPOSE : Normalize the rectangle
---------------------------------------------------------------------------*/
void CZoomView::NormalizeRect (
	CRect &rect)
{
   if (rect.left > rect.right) {
      int r = rect.right;
      rect.right = rect.left;
      rect.left = r;
   }
   if (rect.top > rect.bottom) {
      int b = rect.bottom;
      rect.bottom = rect.top;
      rect.top = b;
   }
} // NormalizeRect

/*---------------------------------------------------------------------------
   FUNCTION: PersistRatio
   PURPOSE : Make a CSize maintain the given ratio (by shrinking if nescessary)
---------------------------------------------------------------------------*/
void CZoomView::PersistRatio (
	const CSize &orig,
	CSize       &dest,
	CPoint      &remainder)
{
	float ratio1 = (float) orig.cx / orig.cy;
	float ratio2 = (float) dest.cx / dest.cy;
	int   newSize;

	// Do nothing if they are the same
	if (ratio1 > ratio2) {
		// Shrink hieght
		newSize = (int)(dest.cx / ratio1);
		remainder.x = 0;
		remainder.y = dest.cy - newSize;
		dest.cy = newSize;
	} else if (ratio2 > ratio1) {
		// Shrink width
		newSize = (int)(dest.cy * ratio1);
		remainder.x = dest.cx - newSize;
		remainder.y = 0;
		dest.cx = newSize;
	}
} // PersistRatio