From 4474334864118e1f20f75b64fe0da5f3cece40f4 Mon Sep 17 00:00:00 2001 From: Rune Lillesveen Date: Tue, 17 Mar 2026 15:50:40 +0100 Subject: [PATCH 1/2] [css-anchor-position-1] Specify scroll offset snapshot timing #10796 Specify that scroll offsets are snapshotted when asked to run snapshot post-layout state steps. Also see HTML PR[1] for when "run snapshot post-layout state steps" are expected to be run. [1] https://github.com/whatwg/html/pull/11613/ --- css-anchor-position-1/Overview.bs | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/css-anchor-position-1/Overview.bs b/css-anchor-position-1/Overview.bs index 26dd34b9fe15..6b45795c0bfd 100644 --- a/css-anchor-position-1/Overview.bs +++ b/css-anchor-position-1/Overview.bs @@ -1056,6 +1056,10 @@ while still allowing as much freedom to anchor to various elements as possible, [=anchor positioning=] uses a combination of [=remembered scroll offsets=] and [=compensating for scroll=]. +The scroll offsets which are used to compute [=remembered scroll offsets=] and +[=default scroll shift=] are snapshotted when asked to +[=run snapshot post-layout state steps=]. +
The details here are technical, but the gist is: @@ -1217,10 +1221,6 @@ specifically, the [=default anchor element=]: as if affected by a [=transform=] (before any other transforms). - Issue: Define the precise timing of the snapshot: - updated each frame, - before style recalc. - Issue: Similar to [=remembered scroll offset=], can we pay attention to transforms on the [=default anchor element=]? From 86fd4cadc2315e12933e67b892228545f710b213 Mon Sep 17 00:00:00 2001 From: "Tab Atkins Jr." Date: Tue, 28 Apr 2026 11:07:55 -0700 Subject: [PATCH 2/2] Apply suggestion from @tabatkins (just rewrapping to semantic line breaks) --- css-anchor-position-1/Overview.bs | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/css-anchor-position-1/Overview.bs b/css-anchor-position-1/Overview.bs index 6b45795c0bfd..cedad5578f0a 100644 --- a/css-anchor-position-1/Overview.bs +++ b/css-anchor-position-1/Overview.bs @@ -1056,9 +1056,8 @@ while still allowing as much freedom to anchor to various elements as possible, [=anchor positioning=] uses a combination of [=remembered scroll offsets=] and [=compensating for scroll=]. -The scroll offsets which are used to compute [=remembered scroll offsets=] and -[=default scroll shift=] are snapshotted when asked to -[=run snapshot post-layout state steps=]. +The scroll offsets which are used to compute [=remembered scroll offsets=] and [=default scroll shift=] +are snapshotted when asked to [=run snapshot post-layout state steps=].
The details here are technical, but the gist is: