Comment 4 for bug 681009

I'll just copy/paste what I posted to mixxx-devel:

visual_playpos is not really that great of a control to hook for doing marquee scrolling because they only update when the player is moving. So if all the players are stopped then the marquee animation will also be stopped.

I haven't responded to the bug yet but I think that a QTimer approach might be fine to stick with for now.

We have a global ~40fps timer that is used to update the waveforms. It is created in src/waveformviewerfactory.cpp. Code-plumbing wise, it will be a little tricky/ugly to get this timer and hook it to widgets other than waveforms. Furthermore, to support marquee scrolling of any widget, we would need to connect this high-ish speed timer to every widget. I'm not sure that's a good thing CPU-wise because it means that every widget will run some handler code (even if it's a no-op) at 40fps. So for now, I'd rather not play with trying to hook this up.