Use button in a dialog to select shape in MFC - c++

Question

I am doing a small drawing tool with MFC.
I define five shapes: rectangle, line, circle, ellipse and dot. int m_drawType is used to switch between five shapes.
The code as below:
void CDrawToolView::OnLButtonDown(UINT nFlags, CPoint point)
{
m_startRect=TRUE;
m_startPoint=point;
m_OldPoint=point;
::SetCursor(m_HCross);
CView::OnLButtonDown(nFlags, point);
}
void CDrawToolView::OnMouseMove(UINT nFlags, CPoint point)
{
CClientDC dc(this);
dc.SetROP2(R2_NOT);
dc.SetROP2(R2_NOT);
dc.SelectStockObject(NULL_BRUSH);
if(TRUE==m_startRect)
{
switch(m_drawType)
{
case 1://Rectangle
::SetCursor(m_HCross);
dc.Rectangle(CRect(m_startPoint,m_OldPoint));
dc.Rectangle(CRect(m_startPoint,point));
m_OldPoint=point;
break;
case 2: //Line
::SetCursor(m_HCross);
dc.MoveTo(m_startPoint);
dc.LineTo(m_OldPoint);
dc.MoveTo(m_startPoint);
dc.LineTo(point);
m_OldPoint=point;
break;
.
.
.
}
}
CView::OnMouseMove(nFlags, point);
}
void CDrawToolView::OnLButtonUp(UINT nFlags, CPoint point)
{
m_startRect=FALSE;
::ClipCursor(NULL);
CClientDC dc(this);
dc.SelectStockObject(NULL_BRUSH);
switch(m_drawType)
{
case 1: //Retangle
dc.Rectangle(CRect(m_startPoint,m_OldPoint));
dc.Rectangle(CRect(m_startPoint,point));
break;
case 2: //Line
dc.MoveTo(m_startPoint);
dc.LineTo(m_OldPoint);
dc.MoveTo(m_startPoint);
dc.LineTo(point);
break;
.
.
.
}
CView::OnLButtonUp(nFlags, point);
}
void CDrawToolView::OnEditShape() // when click menu-edit-shape a dialog is pop up
{
CShapeDlg dlg;
dlg.DoModal();
}
The pop up dialog as below:
I have created a dialog of five buttons. My problem is I don't know how to link between the buttons and these five shapes. Could some one help me?

Answer 1

So your question is how to make the buttons of CShapeDlg set m_drawType?
Your dialog could have a local public drawType variable. Introduce button click event handlers for the buttons.
BEGIN_MESSAGE_MAP(CShapeDlg, CDialog)
ON_BN_CLICKED(IDC_BUTTON1, &CShapeDlg::OnBnClickedButton1)
... etc.
ON_BN_CLICKED(IDC_BUTTON5, &CShapeDlg::OnBnClickedButton5)
END_MESSAGE_MAP()
Make the handlers set the local drawType variable to integer value 0 - 4 as the case may be.
void CShapeDlg::OnBnClickedButton1() { drawType = 0; }
... etc.
void CShapeDlg::OnBnClickedButton5() { drawType = 4; }
Then
if (dlg.DoModal() == IDOK)
m_drawType = dlg.drawType;

Answer 2

The dialog should have an m_drawtype variable that it sets when a button is clicked. When DoModal returns this variable can be read to get the result:
dlg.DoModal();
m_drawtype = dlg.m_drawtype;