TrackControl overflow problem

Hi there.
I was getting strange behaviour with my TrackControl where the slider would jump to the end of my time line range when I reached a certain position. I tracked the issue down to an overflow in the CXTPTrackControlHeader OnMoveSlider (~line 180) method.

int fromPosition = m_ptStartDrag.x * (pControl->GetTimeLineMax() - pControl->GetTimeLineMin()) / rcSliderArea.Width(); int toPosition = pt.x * (pControl->GetTimeLineMax() - pControl->GetTimeLineMin()) / rcSliderArea.Width(); int delta = toPosition - fromPosition;

With large timelines, as I had, the initial multiplication overflowed into negative. The fromPosition and toPosition can actually be removed and the delta performed before the multiplication and division. Even better would be to divide first, as I don't think the difference in rounding would matter. I have made the change in my code and all is working well.

As an aside to this, I would suggest that CXTPTrackControl handled unsigned.

Aaron

No problem. I also found a couple of other places where the same thing occurs.

XTPrackPaintManager::DrawTrackHeader, around line 305.
XTPTrackHeader::OnLButtonDown, around line 418.

Both of those perform out of range multiplications.

Cheers
Aaron