Re: [csswg-drafts] [css-contain] Behavior of slightly offscreen content having`content-visibility:auto` when UA margin around the viewport is 0 (#8407)

I'd also prefer a stable layout.
I'm not sure what you mean with "not-relevant", I think it would make more sense to not skip its contents (as if relevant) so that it stays off-screen (as if not relevant). [Testcase](https://software.hixie.ch/utilities/js/live-dom-viewer/saved/11271)

```html
<!DOCTYPE html>
<style>
body {
  height: 500vh;
}
div {
  width: 500px;
  position: absolute;
  content-visibility: auto;
  contain-intrinsic-height: 1000vmax;
  background: red;
}
</style>
<div>Scroll down</div>
<p style="width: min-content; padding-top: 2em;">
   Lorem ipsum dolor sit amet consectetur adipiscing elit sed do eiusmod tempor incididunt ut labore et dolore magna aliqua rutrum quisque non tellus orci ac id aliquet lectus proin nibh nisl condimentum id eu volutpat odio facilisis mauris sit amet est placerat in egestas erat pulvinar pellentesque habitant morbi tristique senectus et netus pellentesque nec nam aliquam sem et tortor consequat viverra tellus in hac habitasse platea dictumst vestibulum mattis aliquam faucibus purus in massa tempor nec feugiat amet mattis vulputate enim nulla aliquet porttitor lacus sem et tortor consequat id porta nibh venenatis cras lobortis feugiat vivamus at augue eget arcu dictum varius sem nulla pharetra diam sit amet nisl suscipit adipiscing bibendum tincidunt ornare massa eget egestas purus viverra accumsan in nisl luctus venenatis lectus magna fringilla elementum nisi quis eleifend quam adipiscing vitae proin sagittis aliquam ut porttitor leo a diam sed augue lacus viverra vitae congue eu consequat ac massa tempor nec feugiat nisl pretium fusce id velit at risus viverra adipiscing at in tellus integer feugiat et tortor consequat id porta nibh venenatis cras sed felis porttitor lacus luctus accumsan tortor posuere ac ut malesuada bibendum arcu vitae elementum curabitur vitae libero enim sed faucibus turpis in eu aliquet lectus proin nibh nisl condimentum pellentesque dignissim enim sit amet venenatis urna non diam phasellus vestibulum lorem sed tellus integer feugiat scelerisque varius morbi enim nunc faucibus sagittis purus sit amet volutpat consequat mauris nunc congue enim diam vulputate ut pharetra sit ornare arcu dui vivamus arcu felis bibendum ut tristique enim facilisis gravida neque convallis a cras semper auctor neque ullamcorper morbi tincidunt ornare massa luctus accumsan tortor posuere ac ut consequat semper viverra non odio euismod lacinia at quis in mollis nunc sed id semper risus in hendrerit facilisis magna etiam tempor orci eu sapien eget mi proin sed libero enim sed faucibus turpis eu turpis egestas pretium aenean pharetra nisl pretium fusce id velit ut mauris vitae ultricies leo integer malesuada nunc felis bibendum ut tristique et egestas quis ipsum suspendisse ultrices nulla posuere sollicitudin aliquam ultrices eleifend quam adipiscing vitae proin sagittis nisl rhoncus mattis lacus viverra vitae congue eu malesuada fames ac turpis egestas sed tempus urna et pharetra risus quis varius quam quisque id dictum varius duis at consectetur lorem turpis egestas integer eget aliquet nibh praesent tristique magna tempor id eu nisl nunc mi ipsum faucibus vitae aliquet sit amet luctus venenatis lectus magna fringilla urna porttitor rhoncus rhoncus aenean vel elit scelerisque mauris pellentesque rhoncus est pellentesque elit ullamcorper dignissim sed vulputate odio ut enim blandit volutpat urna nec tincidunt praesent semper lacus suspendisse faucibus interdum posuere lorem urna neque viverra justo nec ultrices dui sapien eget est placerat in egestas erat imperdiet sed nec ultrices dui sapien eget mi odio morbi quis commodo odio nibh mauris cursus mattis molestie a iaculis at erat cursus turpis massa tincidunt dui ut ornare lectus sit viverra orci sagittis eu volutpat morbi tempus iaculis urna id volutpat lacus senectus et netus et malesuada fames ac turpis volutpat consequat mauris nunc congue nisi curabitur vitae nunc sed velit dignissim nisl rhoncus mattis rhoncus urna neque viverra hac habitasse platea dictumst vestibulum rhoncus est pellentesque egestas sed tempus urna et pharetra pharetra massa massa commodo elit at imperdiet dui accumsan sit amet nulla facilisi erat nam at lectus urna duis convallis condimentum mattis pellentesque id nibh.
</p>
```

I think it would be unexpected if you start scrolling down, the red box initially disappears, but then when it reached the margin for being considered not relevant, it suddenly becomes visible due to size containment.

So I think elements could be classified as "not relevant" or "maybe relevant". Only the "not relevant" case would skip contents with `content-visibility: auto`. Elements with this circularity would be "maybe relevant".

-- 
GitHub Notification of comment by Loirooriol
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/8407#issuecomment-1426002648 using your GitHub account


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

Received on Friday, 10 February 2023 15:50:44 UTC