Re: [css3-transitions] Transition events on shorthands

On Monday 2013-04-29 11:47 -0700, Dirk Schulze wrote:
> After reading some blog posts [1], I wonder what happens to Transition Events on animating shorthand properties.
> 
> 1) Should just the shorthand with its property name fire?
> 2) Should just the longhand with their property names be fire?
> 3) Should long and shorthands fire?
> 4) Should just changing longhands fire?
> 5) What happens if both change?

https://drafts.csswg.org/css-transitions/#transition-property-property
describes the way shorthands as values of transition-property work
as being that the transitions actually run on the longhand
properties:

  # For the keyword all, or if one of the identifiers listed is a
  # shorthand property, implementations must start transitions for
  # any of its longhand sub-properties that are animatable (or, for
  # all, all animatable properties), using the duration, delay, and
  # timing function at the index corresponding to the shorthand.

Likewise, the definitions of starting of transitions in
https://drafts.csswg.org/css-transitions/#starting define the
starting of transitions as not operating on shorthands.  (Shorthands
also don't have their own computed values, so it doesn't make
sense.)

So events should, as a result, fire only for longhands that
transition.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
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