Re: [css-transitions] List of animatable properties

(cc birtles@)

I believe it was resolved in [0] ('Tracking Animatable Properties') to
prefer tracking animatable state in the specifications that defined the CSS
properties themselves. My understanding of the problem is that a
centralized list became unwieldy to manage; it is easy to forget to update
it when the root specifications change (properties are added, deleted, or
changed such that the animation definition needs to change), and is also
hard to find for implementers looking at a new CSS property to implement
(how do they know they need to look at another spec?)

The last major change to the list was in [1], where it was trimmed down to
only 'legacy' properties that did not define their animation type in their
spec and which I believe it was considered impractical to correct. These
were also moved to web-animations-1[2], as that is now where the core of
the animation model for the web is defined.

Note that for many specs, they define their animation behavior as 'by
computed value', which often falls back to css-values-3[3]; reading the
linked section and then searching for 'interpolat' (to cover 'interpolate'
and 'interpolation') gives the definition for many common value types.

Hope that helps,
Stephen

[0]: https://lists.w3.org/Archives/Public/www-style/2011Sep/0497.html
[1]:
https://github.com/w3c/csswg-drafts/commit/7b816b2c7aef364c8c938bdf2e63cf6cbadc304b#diff-77be26fa8328bad7ef60fb7d85456db2
[2]: https://drafts.csswg.org/web-animations-1/#animation-types
[3]: https://drafts.csswg.org/css-values-4/#combining-values

On Thu, 26 Mar 2020 at 23:17, Gérard Talbot <www-style@gtalbot.org> wrote:

> Fellow www-style colleagues,
>
> There used to be a list of animatable properties in the CSS Transitions
> spec
>
> 9.1. Properties from CSS
> https://www.w3.org/TR/2017/WD-css-transitions-1-20171130/#animatable-css
>
> but now, newer versions of the spec
> https://www.w3.org/TR/css-transitions-1/
> and Editors' draft
> https://drafts.csswg.org/css-transitions/
> no longer enumerate list of this sort (I searched). Is there an url (or
> url#fragment) that lists animatable CSS properties now? Is the removal
> of such list permanent?
>
> MDN has a list
> https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_animated_properties
> but, it seems, none of the (latest stable or Editors') spec has one.
>
> Gérard
>
>