Re: something about clipping in OnCustomdraw

From:
".rhavin grobert" <clqrq@yahoo.de>
Newsgroups:
microsoft.public.vc.mfc
Date:
Fri, 10 Oct 2008 10:40:33 -0700 (PDT)
Message-ID:
<fbd9726c-e8c3-4ed6-9ef6-26576a442618@s50g2000hsb.googlegroups.com>
On 10 Okt., 18:16, ".rhavin grobert" <cl...@yahoo.de> wrote:

On 10 Okt., 18:02, ".rhavin grobert" <cl...@yahoo.de> wrote:

hi folks;-)

the following snipped comes from a customdraw-fn in a slider. As you
can see, i draw my own thumb and want to set some text in the control:

____________________________________________________________

class SHTC_API CQSlider : public CSliderCtrl
{
public:
        CQSlider();
        virtual ~CQSlider();

        // ... other stuff ... //

        // set sliders text, may contain '%d' (or %x...) for va=

lue

        void QTitleSet(LPCTSTR szTitle);

protected:
        //{{AFX_MSG(CQSlider)
        afx_msg void OnCustomdraw(NMHDR* pNMHDR, LRESULT* pResu=

lt);

        //}}AFX_MSG

        DECLARE_MESSAGE_MAP()

private:
        void _DrawThumb(NMCUSTOMDRAW& nmcd);
        void _DrawText(NMCUSTOMDRAW& nmcd);

        CString m_scTitle;

};

//---------------------------------------------------------------------=

--------

void CQSlider::OnCustomdraw(NMHDR* pNMHDR, LRESULT* pResult)
{
    NMCUSTOMDRAW nmcd = *(LPNMCUSTOMDRAW)pNMHDR;

        switch (nmcd.dwDrawStage)
        {
        case CDDS_PREPAINT:
                *pResult = CDRF_NOTIFYITEMDRAW | CDRF=

_NOTIFYPOSTPAINT;

                break;

        case CDDS_ITEMPREPAINT:
                switch (nmcd.dwItemSpec)
                {
                case TBCD_TICS:
                        *pResult = CDRF_DODEF=

AULT;

                        break;
                case TBCD_THUMB:
                        _DrawThumb(nmcd);
                        *pResult = CDRF_SKIPD=

EFAULT;

                        break;
                case TBCD_CHANNEL:
                        *pResult = CDRF_DODEF=

AULT;

                        break;
                }
                break;

        case CDDS_POSTPAINT:
                _DrawText(nmcd);
                break;

        default:
                *pResult = CDRF_DODEFAULT;
        }

}

//---------------------------------------------------------------------=

--------

void CQSlider::_DrawText(NMCUSTOMDRAW& nmcd)
{
        CDC* pDC = CDC::FromHandle(nmcd.hdc);

        CRect rcClient;
        GetClientRect(&rcClient);

        CString scText;
        scText.Format(m_scTitle, GetPos());
        pDC->SetBkMode(TRANSPARENT);
        pDC->SelectClipRgn(NULL);
        pDC->DrawText(scText, rcClient, DT_CENTER | DT_BOTTOM |
DT_SINGLELINE);

}

____________________________________________________________

the problem is: first time (initial, get focus), the text is drawn
correctly, but then, when moving the slider, everything except the
thumb gets clipped, so pDC->SelectClipRgn(NULL) seems to dont do
anything at all.

any suggestions welcome,

~.rhavin;)


oh and i should add that pDC->SelectClipRgn(NULL) returns SIMPLEREGION
but shouldnt it return NULLREGION !?


played with SetBoundsRect(), but that doesnt help either;-/

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