[Lazarus] Mouse wheel scroll bar increment size?

Vincent Snijders vsnijders at vodafonevast.nl
Mon Jun 29 14:41:55 CEST 2009

Bruce Tulloch schreef:
> Interesting thread but I may have not asked the right question...
> I'm trying to understand the scaling of the mousewheel as it affects the
> TScrollbar control specifically. Not for scrolling in SynEdit or case of
> scrolling text or similar purposes in a generic desktop application.
> Instead I'm looking at using it to scroll other types of data
> (waveforms, images etc) on screen using a TScrollBar as the controlling
> widget where the scale at which the data moves definitely wants to be
> under application (not O/S or desktop preferences) control.

I am confused, do you want to use the scrollbar for scrolling or the mouse wheel?

If you want to use the mouse wheel, then use one of the OnMouseWheel* events.
If you want to use the scrollbar, use the events of the scrollbar, if necessary.

If you don't handle the mouse wheel events, then the LCL widgetset interface or the 
underlying widget may translate the mousewheel to a scroll message.


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