CSS View Transitions 2 2024-04-02

[noamr]

Name of spec to be reviewed: CSS View Transitions 2

URL of spec: https://drafts.csswg.org/css-view-transitions-2/

Do you need a reply by a particular date? No

Please point to the results of your own self-review: Same as #44, the checklist is mostly not applicable because it enhances an existing visual feature, with the same provisions as existing today.

Where and how to file issues arising? https://github.com/w3c/csswg-drafts/issues tagged [css-view-transitions-2]

Pointer to any explainer for the spec: https://github.com/WICG/view-transitions/blob/main/cross-doc-explainer.md

Other comments:

CSS View Transitions 2 augment CSS View Transitions 1, by enabling the transitions to take place across document. The spec also improves the ergonomics of specifying a view transition.
There are no particular areas where we require feedback on this, as #44 probably captures this.

[AutoSponge]

I think we just want to understand whether the transition between oldDocument and newDocument (different authors) needs one, both, or neither to respect prefers-reduced-motion. In the case of neither, the UA is responsible for skipping all transitions when the user prefers reduced motion.

[noamr]

I think we just want to understand whether the transition between oldDocument and newDocument (different authors) needs one, both, or neither to respect prefers-reduced-motion. In the case of neither, the UA is responsible for skipping all transitions when the user prefers reduced motion.

The animation occurs on the destination page. It is a standard animation defines in CSS/JS, and it's up to the author to respect prefers-reduced-motion. Also the source page can decide to not capture any elements if prefers-reduced-motion is declared, so really if either page respects prefers-reduced-motion the animation would change.

This is not different from any other transition, where the UA doesn't decide by itself to cancel animations based on prefers-reduced-motion but rather delegates it to the author.

[AutoSponge]

It sounds like both need to respect prefers-reduced-motion for everyone to be included. I'd feel better if at least one of the examples included that or it was stated in an accessibility considerations section. These are my opinions as the liaison. APA may differ. cc @matatk