- From: Tab Atkins Jr. via GitHub <sysbot+gh@w3.org>
- Date: Mon, 09 Sep 2024 22:33:43 +0000
- To: public-css-archive@w3.org
tabatkins has just created a new issue for https://github.com/w3c/csswg-drafts: == [css-align][css-anchor-position] Default safety and fixpos == [continuing from #10859] An issue arises if the "original containing block" is the viewport. The position of this rect responds to scrolling, and thus anything that uses it must be aware of the compositor limitations. In particular, we can't actually respond to it *at layout time*, like we would normally do for alignment. It needs to be handled similarly to [scroll adjustment in Anchor Pos](https://drafts.csswg.org/css-anchor-position/#scroll), where we initially position it as if everything were at the initial scroll position, then shift it in the compositor thread to compensate for accumulated scroll offsets. Specifically, then, if the element is using the viewport as its original CB (aka it's fixpos and nothing is intercepting it), it needs to *always* default to unsafe alignment, and then we handle the medium-safety as a scroll adjustment using wording similar to what's in Anchor Positioning. The *observable effect* of this should be identical for users of the feature - the element shifts to stay on-screen if possible. It's just the actual definition that needs to change to be implementable. Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/10860 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Monday, 9 September 2024 22:33:44 UTC