Re: [csswg-drafts] [css-animations-2] Proposal: Time-based Keyframe Animations (#4907)

This sounds good. Note that #4862 is also suggesting adding an auto duration for scroll timelines and we have wanted that for groups too. In fact, the (very very draft) Web Animations level 2 spec introduces the [intrinsic iteration duration](https://drafts.csswg.org/web-animations-2/#intrinsic-iteration-duration) concept and [auto keyword](https://drafts.csswg.org/web-animations-2/#duration) for this.

Note that Web Animations (WAAPI) is a product of the CSSWG so it's fine to include that in scope. In fact, I think the best path forward here would be to work on the intrinsic iteration duration concept and scaling behavior such that it covers this case, the group case, and scroll timeline case.

For groups, in particular, I think the concept would also allow specifying child keyframe effects without any duration (only keyframe offsets), and then using the duration specified on an ancestor to calculate their final duration.

That is, similar to layout calculations, child nodes would pass up their resolved intrinsic durations, and bubble them up to the root, and then in a subsequent top-down traversal, we'd fill in the unresolved times based on the available time as well as scaling resolved times.

(In the very early days of planning Web Animations we had a number of proposals like this that we later realized were simply "flexbox, but for time".)

@flackr @majido Does #4890 harmonize with this in a way that covers groups too?

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Received on Thursday, 9 April 2020 04:52:28 UTC