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Research Layout Instability API + scroll anchoring interaction
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Description

Does the API report an instability event or not when scroll anchoring fully compensates for DOM insertions happening above the viewport?

https://drafts.csswg.org/css-scroll-anchoring/

Event Timeline

Gilles created this task.Apr 4 2019, 1:52 PM
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptApr 4 2019, 1:52 PM
Gilles triaged this task as Medium priority.Apr 4 2019, 1:52 PM
Gilles updated the task description. (Show Details)
Gilles added a comment.Apr 6 2019, 9:57 AM

Verified this on Vagrant and a LayoutJank event is fired even if scroll anchoring fully compensated it, meaning that it have no visible effect to the user.

Scratch that: it only fired events when there was actually a visible effect, which happened to be on the left sidebar that moved up in my case. This means we're not getting false positives due to scroll anchoring, the events we are seeing are real.

Gilles closed this task as Resolved.Apr 6 2019, 10:01 AM