[csswg-drafts] [css-transitions][css-values][web-animations] Where should animated property type definitions live

birtles has just created a new issue for 
https://github.com/w3c/csswg-drafts:

== [css-transitions][css-values][web-animations] Where should animated
 property type definitions live ==
We currently define a number of animatable property types in [CSS 
Transitions](https://drafts.csswg.org/css-transitions/#animatable-properties).
 These definitions specify what it means to _interpolate_ values of 
each type. New specs that define new types (e.g. transform lists, 
filter lists, shapes etc.) are expected to provide their own 
definitions of interpolation.

Web Animations extends the [set of required 
definitions](https://w3c.github.io/web-animations/#procedures-for-animating-properties)
 to include not only 
[interpolation](https://w3c.github.io/web-animations/#animation-interpolation),
 but also 
[addition](https://w3c.github.io/web-animations/#animation-addition), 
[accumulation](https://w3c.github.io/web-animations/#animation-accumulation)
 and 
[distance](https://w3c.github.io/web-animations/#distance-computation).
 It also provides some [default 
definitions](https://w3c.github.io/web-animations/#animation-types) 
for these and a very incomplete set of basic animation types.

In order to implement features like additive animation or paced 
animation we need to fill out the definitions of addition / distance 
for many of these types. In general they're not too hard and SVG 
provides a starting point since addition and pacing are animation 
features originally used in SVG. Nevertheless, the definitions need to
 be written up somewhere.

The question is, where do these definitions belong? For now let's 
assume that specs that introduce new types will provide their own 
definitions along with the new type, and let's limit the discussion to
 existing types like length etc.

Some options are:

* Add them to CSS Transitions — feels odd to add these features in 
when CSS Transitions doesn't use them (or at least not yet, and won't 
likely use them in the near future, although CSS Animations might)
* Add them to Web Animations — probably involves copying all the 
interpolation definitions over from CSS Transitions. This somehow 
seems a little odd for me. It seems like Web Animations should 
probably just be the model and these definitions should belong in a 
purely CSS spec.
* Add them to CSS Values (Level 4?)
* Create a new "Animated property types" spec

I spoke to @dbaron yesterday who suggested the last two possibilities.
 @tabatkins @fantasai @shans I wonder if you have any suggestions / 
preference?

Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/338 using your GitHub 
account

Received on Friday, 22 July 2016 01:45:11 UTC