[fltk.general] Re: Run code when Fl_Scroll stops scrolling? - Forums

On Friday, 9 September 2022 at 08:29:09 UTC+1 jakub wrote:

Hello!

As described in https://stackoverflow.com/questions/73653471/fltks-fl-scroll-run-code-in-reaction-to-scrolling-happening, I want to run a function when Fl_Scroll's yposition changes or stops changing. I did not find any callback or event that would help me with that.

In the end I solved my need by checking the yposition every 100ms but want to pick your brains for alternative / better solutions. Thank you!

Is it not possible to subclass your own scroll and then, in the handle method, simply check for the user releasing the mouse button drag?

Or even in the subclass draw() method, note when the widget is redrawn at a different offset, perhaps (though that seems like it would be trickier, perhaps...)

Is the redrawing of the scroll a slow operation, such that it completes a significant time after the user releases the button?

That said, polling on a timeout possible is not to hideous a solution, since it does allow for the redraw of the scroll to complete asynchronously to toher events in the system and still do the Right Thing, in effect.