Add animation step callback to jQuery UI effects?

Add animation step callback to jQuery UI effects?

Hi!

Would it be reasonable to add a per-animation-step callback to jQuery UI effects?

So that when you e.g. hide() something,
then, on each hide animation step, the per-animation-step callback is invoked.

Background:
I want to redraw SVG arrows on each animation step, when e.g. something is slided/folded in/out. I've done this for the Resizable interaction (there's a resize event, triggered on each resize step). But for jQuery UI effects, there are no per-animation-step callbacks to hook into.
(The SVG arrows point to different parts of the Web page, whose positions change when animations run, so I redraw the SVG arrows.)

Other approaches?
Is there some other approach you can think of? I've tested using setInterval(...) to schedule a redraw of the SVG arrows e.g. each 50 ms, until the effect animation completes, but the arrows are redrawn either too frequently (CPU expensive) or too infrequently (jerky animations).
--- The best option (with no step callback in jQuery UI) might be to copy and modify the relevant jQuery UI effects, to add a step callback. But then I'd need to maintain that duplicated code.

Related:
These two forum threads seem to be related:

(Should I have posted this in the `development' forum?)

Kind regards, Kaj-Magnus