Re: [csswg-drafts] [css-sizing-4] Should aspect-ratio be used for abspos `top: 0; bottom: 0;`? (#5151)

The CSS Working Group just discussed ``[css-sizing-4] Should aspect-ratio be used for abspos `top: 0; bottom: 0;`?``, and agreed to the following:

* `RESOLVED: Accept proposal`

<details><summary>The full IRC log of that discussion</summary>
&lt;dael> Topic: [css-sizing-4] Should aspect-ratio be used for abspos `top: 0; bottom: 0;`?<br>
&lt;dael> github: https://github.com/w3c/csswg-drafts/issues/5151<br>
&lt;tantek> just going to note that existing OS UI use of color is insufficient to determine feature flexibility, new OS's may and will do new things with colors etc.<br>
&lt;astearns> PR: https://github.com/w3c/csswg-drafts/commit/9594b70729ff481ea933a3e3d07a85423122e0eb<br>
&lt;dael> fantasai: Issue raised was if you have abspos element with top, bottom, left set non-auto but right is auto should that use aspect-ratio in sizing width. TabAtkins and I thought it made sense so drafted spec fot hat.<br>
&lt;dael> fantasai: If width and height are both auto we ignore a-r for width and use it for height. In this case it's easy to determine. Width has only one constraint so it's variable and makes sense to use height for deterministic value<br>
&lt;fantasai> https://github.com/w3c/csswg-drafts/commit/9594b70729ff481ea933a3e3d07a85423122e0eb<br>
&lt;dael> fantasai: Drafted wording into positioning spec. Wanted to check with WG if it's acceptable<br>
&lt;dael> Rossen_: Would align-stretch work the same or have same behavior in this case?<br>
&lt;dael> fantasai: Don't remember which align-stretch does<br>
&lt;dael> Rossen_: My understanding is align-stretch should behave same as if fixed height which should then have the same expected behavior for a-r, wouldn't it?<br>
&lt;dael> Rossen_: Not sure if this is related to position spec<br>
&lt;dael> fantasai: align-stretch takes prescience over a-r. Neight is stretch, width and heigh auto, but can stretch b/c top:- bottom:0. Take that as a definite height where we can calculate the width<br>
&lt;fantasai> s/prescience/precedence/<br>
&lt;fantasai> s/Neight/If neither/<br>
&lt;dael> Rossen_: Back to top and bottom 0. Other opinions or reasons why the aspect-ratio shouldn't behave this way?<br>
&lt;dael> cbiesinger: On behalf of Chrome I support<br>
&lt;dael> Rossen_: This isn't just about top:0 bottom:0 it would be same with top:10.<br>
&lt;dael> fantasai: Right. It's non-auto<br>
&lt;dael> dholbert: This is any element with an aspect ratio?<br>
&lt;dael> fantasai: Problem is we have compat requirements for images. For a replaced element it's slightly different. Replaced elements don't stretch between constrained insets and we can't change due to compat. aspect-ratio on non-replaced we figured we can do the thing that makes most sense.<br>
&lt;dael> fantasai: Question is do we use it to resolve height or width in this case since height can come from size of containing block.<br>
&lt;dael> Rossen_: Objections or other comments?<br>
&lt;dael> RESOLVED: Accept proposal<br>
</details>


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Received on Wednesday, 1 July 2020 23:59:23 UTC