sketcherview.cpp

Beginning Visual C++ 6源码。Wrox。

// SketcherView.cpp : implementation of the CSketcherView class
//

#include "stdafx.h"
#include "Sketcher.h"

#include "Elements.h"
#include "SketcherDoc.h"
#include "SketcherView.h"

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

/////////////////////////////////////////////////////////////////////////////
// CSketcherView

IMPLEMENT_DYNCREATE(CSketcherView, CView)

BEGIN_MESSAGE_MAP(CSketcherView, CView)
	//{{AFX_MSG_MAP(CSketcherView)
	ON_WM_LBUTTONDOWN()
	ON_WM_LBUTTONUP()
	ON_WM_MOUSEMOVE()
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CSketcherView construction/destruction

CSketcherView::CSketcherView()
{
	// TODO: add construction code here
   m_FirstPoint = CPoint(0,0);         // Set 1st recorded point to 0,0
   m_SecondPoint = CPoint(0,0);        // Set 2nd recorded point to 0,0
   m_pTempElement = NULL;              // Set temporary element pointer to 0
}

CSketcherView::~CSketcherView()
{
}

BOOL CSketcherView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CSketcherView drawing

void CSketcherView::OnDraw(CDC* pDC)
{
	CSketcherDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
}

/////////////////////////////////////////////////////////////////////////////
// CSketcherView printing

BOOL CSketcherView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CSketcherView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CSketcherView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CSketcherView diagnostics

#ifdef _DEBUG
void CSketcherView::AssertValid() const
{
	CView::AssertValid();
}

void CSketcherView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CSketcherDoc* CSketcherView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CSketcherDoc)));
	return (CSketcherDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CSketcherView message handlers

void CSketcherView::OnLButtonDown(UINT nFlags, CPoint point) 
{
	// TODO: Add your message handler code here and/or call default
   m_FirstPoint = point;               // Record the cursor position	
   SetCapture();                       // Capture subsequent mouse messages
}

void CSketcherView::OnLButtonUp(UINT nFlags, CPoint point) 
{
   if(this == GetCapture())
      ReleaseCapture();        // Stop capturing mouse messages
 
   // Make sure there is an element
   if(m_pTempElement)
   {
      // Call a document class function to store the element
      // pointed to by m_pTempElement in the document object

      delete m_pTempElement;   // This code is temporary
      m_pTempElement = 0;      // Reset the element pointer
   }
}

void CSketcherView::OnMouseMove(UINT nFlags, CPoint point)
{
   // Define a Device Context object for the view
   CClientDC aDC(this);
   aDC.SetROP2(R2_NOTXORPEN);    // Set the drawing mode
   if((nFlags & MK_LBUTTON) && (this == GetCapture()))
   {
      m_SecondPoint = point;     // Save the current cursor position

      if(m_pTempElement)
      {
         // Redraw the old element so it disappears from the view
         m_pTempElement->Draw(&aDC);
         delete m_pTempElement;        // Delete the old element
         m_pTempElement = 0;           // Reset the pointer to 0
      }

      // Create a temporary element of the type and color that
      // is recorded in the document object, and draw it
      m_pTempElement = CreateElement();  // Create a new element
      m_pTempElement->Draw(&aDC);        // Draw the element
   }
}

// Create an element of the current type
CElement* CSketcherView::CreateElement()
{
   // Get a pointer to the document for this view
   CSketcherDoc* pDoc = GetDocument();
   ASSERT_VALID(pDoc);                  // Verify the pointer is good

   // Now select the element using the type stored in the document
   switch(pDoc->GetElementType())
   {
      case RECTANGLE:
         return new CRectangle(m_FirstPoint, m_SecondPoint, pDoc->GetElementColor());

      case CIRCLE:
         return new CCircle(m_FirstPoint, m_SecondPoint, pDoc->GetElementColor());

      case CURVE:
         return new CCurve(pDoc->GetElementColor());

      case LINE: 
         return new CLine(m_FirstPoint, m_SecondPoint, pDoc->GetElementColor());

      default:
         // Something's gone wrong
         AfxMessageBox("Bad Element code", MB_OK);
         AfxAbort();
         return NULL;
   }
}