Re: Drawing a selection box using CRectTracker

From:

"dan" <dan@company.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 27 May 2007 17:30:35 -0400

Message-ID:

<eEfrKZKoHHA.3952@TK2MSFTNGP03.phx.gbl>

From the code you have posted, I don't think that you need OnLButtonUp()
handler. Move the code from your OnLButtonUp() to OnLButtonDown() - i.e.
right after the call to TrackRubberBand().
Do not capture/release the mouse.

Example:
void CSCMLaserView2::OnLButtonDown(UINT nFlags, CPoint point)
{
    ...
    if (m_theRectTracker.TrackRubberBand(this,point,TRUE)) {
        CSCMLaserDoc* pDoc = GetDocument();
        ASSERT(pDoc != NULL);
        ....
    }
}

"Anders Eriksson" <andis59@gmail.com> wrote in message
news:u9p5exj3wnmc.dlg@ostling.com...

Hello,

I have an MFC SDI CView application and I want to draw an selection box
when the user left clicks and move the mouse. I have found the
CRectTracker
class but I can't get it to work

I have this code:

void CSCMLaserView2::OnLButtonDown(UINT nFlags, CPoint point)
{
SetCapture();
m_startPt = point;
m_theRectTracker.TrackRubberBand(this,point,TRUE);
}

void CSCMLaserView2::OnLButtonUp(UINT nFlags, CPoint point)
{
//Release the capture on the mouse
ReleaseCapture();
CSCMLaserDoc* pDoc = GetDocument();
ASSERT(pDoc != NULL);
CClientDC dc(this);
OnPrepareDC(&dc);

// Converts screen coordinates into logical ones
dc.DPtoLP(&point);
dc.DPtoLP(&m_startPt);
// Select object

pDoc->SelectObjectByWindow((double)m_startPt.x/m_dViewScale,(double)m_startPt.y/m_dViewScale,(double)point.x/m_dViewScale,(double)point.y/m_dViewScale);
Invalidate();
}

No box will be shown! If I remove the SetCapture/RelaseCapture I will get
a
box but then the OnLButtonUp() will never be called...

Please Help!

// Anders
--
English is not my first, or second, language
so anything strange, or insulting, is due to
the translation.
Please correct me so I may improve my English!