button states with animation instead of class

[softlion]

I would like to animate a skinned button state change (fade in push skin fade out normal skin).
For this uniform needs one or more callback delegates / custom events on button state change.

[shehi]

Can't this be done with CSS-3? I realize you might require older browser compatibility, but Uniform already has performance problems when it comes to few dozen form elements: I am not sure how it will benefit us if we add animation related handlers as well.

@fidian , thoughts?

[fidian]

I think there could be advantages to having a callback that's called when classes change. It opens up a whole world of possibilities for developers. The code wouldn't have to be that massive - simply check if a callback is registered for the elements and then call it with something like "apply", "hover-start", "focus", "hover-end", "blur", "removed", etc. I don't remember exactly what we use for events, but I think it would be easiest to mimic that. Allow the developer to take whatever action they want on state changes.

I also think that the fading transition that is being described by @softlion could be done more easily with CSS3 for this request. Perhaps callbacks would be more appropriate for the next release?