- From: Rune Lillesveen via GitHub <noreply@w3.org>
- Date: Fri, 29 Aug 2025 13:15:46 +0000
- To: public-css-archive@w3.org
Our intention is to implement what the spec says: https://drafts.csswg.org/css-anchor-position-1/#last-successful-position-option > This sounds like Chrome saving the last successful position option in the element style, or some sort of data structure that goes away on display: none, so when display is changed to something else, the last successful position option isn't there anymore. Maybe we should amend the resolution to include display? No, it's a result of Chrome not considering an element to be absolute positioned when in does not have a principal box here. Is that incorrect? > when the "base style" of the element changes (e.g by adding/removing a class from an element, see https://github.com/web-platform-tests/wpt/blob/719745a09c32182d0b0785a7ac8c393cc44d8c51/css/css-anchor-position/base-style-invalidation.html) This has nothing to do with the last successful position option. It's about finding a new fallback when the currently applied one makes the anchored element overflow the IMCB. > when a position-try fallback rule doesn't refer to an anchor, and the base style changes (???) (see https://github.com/web-platform-tests/wpt/blob/719745a09c32182d0b0785a7ac8c393cc44d8c51/css/css-anchor-position/anchor-position-non-anchored-fallback.html) Same, not about last successful. The anchored element first overflows the IMCB both with the base styles and with the fallback applied (positioned below the anchor which is 100vh) which ends up using the base styles since none of the options fit. Then, the anchor is resized so that the anchored element fits below the anchor, not overflowing the IMCB. In both tests above, we don't even reach the resizeObserver time (when last successful is recorded) before we do all the relevant changes for the tests. -- GitHub Notification of comment by lilles Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/12577#issuecomment-3237008641 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Friday, 29 August 2025 13:15:46 UTC