[css3-transitions] supporting 'transition-delay' on non-animatable properties?

has a special case for the animation of 'visibility' to allow
authors to perform certain special effects, such as hiding elements
at a certain time after a transition starts.

In https://bugzilla.mozilla.org/show_bug.cgi?id=521890#c4 Justin
Dolske (who was converting the animations in our videocontrols for
HTML5 video to transitions) suggested that perhaps
'transition-delay' could apply to all properties, not only those
that are animatable.

This would be relatively straightforward for us to implement, and
would give authors significantly more flexibility in handling
transitions of non-animatable properties that they want to happen at
the end of a transition of animatable properties.  (And, in
particular, they could use 'display', which often has better
performance characteristics when large amounts of content are

If we did this, though, we may (or may not) want to remove the
exception for visibility.  Removing the exception would require
adding a transition-delay for visibility using the trick for getting
reversing transitions, e.g.:
  p { visibility: hidden; }
  p.shown { visibility: visibile; }
  p.shown { transition: visibility 0 1s; } /* not specified for p */
which would likely make the 'transition' property more complicated
when combined with other properties.

Do people think this would be useful, and are other implementors


L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/

Received on Saturday, 28 November 2009 18:04:41 UTC