Re: [csswg-drafts] How widely should HTML's 'aspect-ratio' presentational attribute be applied? (#5608)

The CSS Working Group just discussed `How widely should HTML's 'aspect-ratio' presentational attribute be applied?`, and agreed to the following:

* `RESOLVED: apply aspect ratio pres hint to img, <input type=image>, video, canvas`

<details><summary>The full IRC log of that discussion</summary>
&lt;heycam> Topic: How widely should HTML's 'aspect-ratio' presentational attribute be applied?<br>
&lt;heycam> github: https://github.com/w3c/csswg-drafts/issues/5608<br>
&lt;heycam> TabAtkins: Emilio brought up in the HTML spec that it would make sense to make the aspect-ratio attribute integration from width/height setting intrinsic size, to being them setting an intrinsic ratio pres hint<br>
&lt;heycam> ... I wrote the spec text for it<br>
&lt;heycam> ... Domenic asked which elemetns it should apply to<br>
&lt;heycam> ... prev spec text applied to img specifically<br>
&lt;heycam> ... (side discussion about &lt;picture>)<br>
&lt;heycam> ... but there are other elements that we do use width/height on<br>
&lt;heycam> ... video, possibly embed/object<br>
&lt;heycam> ... canvas, &lt;input type=image><br>
&lt;jensimmons> q<br>
&lt;jensimmons> q+<br>
&lt;heycam> ... first question, does it make sense to widen the spec text from the previous img/picture only, and if so, which elements should we expand it to?<br>
&lt;heycam> ... I think we should, and go with elika's list<br>
&lt;heycam> ... embed/object applying an intrinsic ratio doesn't always apply)<br>
&lt;emilio> q+<br>
&lt;heycam> jensimmons: to remind everyone, this is about improving the experience for users while the page is loading<br>
&lt;heycam> ... the intention is that it has no affect on layout after these assets have loaded<br>
&lt;Rossen_> ack jensimmons<br>
&lt;heycam> ... once an image has loaded, it should get the same layout it would've had<br>
&lt;heycam> ... should work the same way for video<br>
&lt;heycam> ... they do have an intrinsic aspect ratio<br>
&lt;heycam> ... should apply to any HTML element where this is true<br>
&lt;heycam> ... so does not apply to a typical iframe, since they don't have intrinsic aspect ratio<br>
&lt;heycam> ... it's also true that embed/object can sometimes have an intrinsic aspect ratio<br>
&lt;florian> q+<br>
&lt;heycam> ... but if there are complications it's not critical<br>
&lt;heycam> emilio: I agree with this<br>
&lt;Rossen_> ack emilio<br>
&lt;heycam> ... when we initially implemented this for img, we still didn't have the compat requirements<br>
&lt;heycam> ... I think this is pretty reasonable<br>
&lt;heycam> florian: makes a lot of sense to me<br>
&lt;Rossen_> ack florian<br>
&lt;heycam> ... given the text you're replacing didn't apply to these things, is the compat story different for img and the things that are like it?<br>
&lt;heycam> ... or it all falls into the same bucket?<br>
&lt;heycam> emilio: when we did it for img, we override the aspect ratio, but people put wrong values<br>
&lt;heycam> ... the auto value is like a low priority hint<br>
&lt;heycam> ... I think the compat impact is going to be extremely low<br>
&lt;heycam> florian: canvas loads a bit differently from these other things<br>
&lt;heycam> ... you don't load an external file<br>
&lt;heycam> TabAtkins: intrinsic size is based on the backing store<br>
&lt;heycam> florian: script controlled? and so if the script hasn't run yet it's a similar situation?<br>
&lt;heycam> myles: it's based on the attributes on the element<br>
&lt;heycam> TabAtkins: you're right<br>
&lt;Rossen_> q?<br>
&lt;heycam> ... but it would still be consistent with images<br>
&lt;heycam> florian: less useful but still doesn't hurt<br>
&lt;heycam> Rossen_: in the case of picture/srcset, does it come from the first image?<br>
&lt;heycam> emilio: I think it would be the actual &lt;img> inside the picture<br>
&lt;heycam> ... but there's another PR to make width/height apply to src<br>
&lt;heycam> ... there's no precedent for other elements' attributes affecting intrinsics<br>
&lt;heycam> TabAtkins: but that's behind discussed elsewhere<br>
&lt;heycam> s/behind/being/<br>
&lt;TabAtkins> img, input type=image, video, canvas<br>
&lt;heycam> RESOLVED: apply aspect ratio pres hint to img, &lt;input type=image>, video, canvas<br>
&lt;TabAtkins> &lt;br dur=10min> (back at :10 after your hour)<br>
</details>


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Received on Monday, 19 October 2020 21:01:08 UTC