Re: [csswg-drafts] [css-animations-2] Move scroll and event animation triggers to independent namespace (#12336)

> I'm worried that while we overlooked the fact that timelines are one-dimensional, which we managed to ignore so far since webpages are rarely scrolled in 2D, this won't be so easy to overlook with pointer timelines. I.e. trigger if your pointer crosses a point in Y axis, but is not really on top of an element on the X axis.

Yes, I had considered this as well. If we pursue `view-trigger-*` instead of `timeline-trigger-*` then we could constraints in both axes. E.g.

```css
.subject {
  view-trigger-name: --play-every-time-contained;

  /* Play when in the cover range in both axes */
  view-trigger-block-entry-range: contain;
  view-trigger-inline-entry-range: contain;

  /* Reset when completely out of view */
  view-trigger-block-exit-range: cover;
  view-trigger-inline-exit-range: cover;

  /* Play forwards on entry, reset on exit */
  view-trigger-action: play / reset;

  animation: fadein 1s;
  animation-trigger: --play-every-time-constrained;
}
```

I'm not sure what the most effective short-hands would be as with both block and inline entry and exit ranges there's a lot of individual values to potentially specify, however this is why I thought using an independent namespace is a good idea - as none of these properties would make sense on event-triggers.

-- 
GitHub Notification of comment by flackr
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/12336#issuecomment-3197398109 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Monday, 18 August 2025 15:27:28 UTC