Computed Value / Animation Updates [aka If You Edit CSS Specs You Should Read This]

So we've recently updated Working Drafts of:

* Web Animations Level 1
    https://www.w3.org/TR/web-animations-1/
    https://www.w3.org/TR/2018/WD-web-animations-1-20181011/#changes-since-last-publication

* CSS Animations Level 1
    https://www.w3.org/TR/css-animations-1/
    Fixed issues 3119, 2797, 2666 in csswg-drafts github.

* CSS Transitions Level 1
    https://www.w3.org/TR/css-transitions-1/
    https://www.w3.org/TR/css-transitions-1/#changes

* CSS Values and Units Level 4
    https://www.w3.org/TR/css-values-4/
    Added rules for value combinations and clarified computed values.

One of the major changes was to reorganize the text describing
computed values and animation types.

    * Type-specific information about computation, interpolation,
      addition, and accumulation is now largely contained in the
      Values and Units module. See
        https://www.w3.org/TR/css-values-4/#combining-values
      and references to those terms throughout the spec. Patch at
      https://github.com/w3c/csswg-drafts/commit/e3b15849d0c2f0677cffaa0561f3660593ce4ea3

    * Animation type information has been removed from Transitions,
      simplified to rely on computed value types, and inserted into
      the Web Animations module:
        https://www.w3.org/TR/web-animations-1/#animating-properties

    * Likewise, the animation type tables of the CSS2+ properties
      have been condensed down to the following appendix:
        https://www.w3.org/TR/web-animations-1/#animation-types

    * The Computed Value and Animation lines in the propdef tables
      of almost all CSS modules have been updated accordingly [1] on
      csswg.org; it may take awhile for the changes to propagate
      out to w3.org. The remaining stragglers will be fixed in [2]
      [1] https://github.com/w3c/csswg-drafts/commit/8dbce74efa894eb8c7183440bd312316cb1ce449
      [2] https://github.com/w3c/csswg-drafts/pull/3198

What this means FOR YOU:

   * Specs defining value types whose behavior doesn't fall out of
     the behaviors defined in css-values-4 need to make sure they're
     clearly defining their value computation/combination operations.

   * Computed Value lines in propdef tables need to be sufficiently
     rigorous to correctly define the property's animation and,
     eventually, TypedOM behavior in addition to inheritance and
     (for properties that return computed style) getComputedStyle().

   * If your spec defines properties, it is very likely now
     out-of-date on /TR. Plan on getting it published sometime in
     the not-too-distant future. :)

   * This is a first pass on these edits, we expect some refinement
     is necessary. Please feel free to suggest improvements however
     minor.

~fantasai and Brian Birtles

[This is a slightly reworded version of the www-style announcement;
   https://lists.w3.org/Archives/Public/www-style/2018Oct/0007.html
original was sent to CSSWG editors, copying here for public archive.]

Received on Friday, 12 October 2018 22:04:39 UTC