[css-sizing] max-content size of percentage-sized replaced elements

[fantasai]

We recently resolved that the max-content size of replaced elements with percentage size/max-size and an intrinsic aspect ratio is calculated from 300x150 and the aspect ratio. The upside is that we have a definition that isn't zero. The downside is that 300x150 is rarely a useful size, and isn't customizable.

So I was just thinking, what if we try using the min-width/min-height instead (where possible, i.e. not when calculating the min-width/min-height value itself)? If either of them is not auto, use that plus the aspect ratio to calculate the min-content size, otherwise fall back to 300x150.

[css-meeting-bot]

The Working Group just discussed Sizing.

RESOLVED: Go with this approach and see if we run into compat concerns.

The full IRC log of that discussion

<gregwhitworth> topic: Sizing
<astearns> github: https://github.com//issues/1722
<gregwhitworth> Rossen: max-content size of replaced elements
<gregwhitworth> fantasai: we discussed what to do with replaced elements that is percentage sized that has an intrinsic aspect ratio
<gregwhitworth> fantasai: *gives an example*
<gregwhitworth> fantasai: if there is a specified min-width or min-height use that rather than the intrinsic aspect ratio in that dimension
<gregwhitworth> dbaron: the effect that that would have is that if your min-width or min-height is smaller than the intrinsic size in that direction then you use that
<gregwhitworth> dholbert: if it's not min-width/height of auto?
<gregwhitworth> fantasai: yes
<gregwhitworth> dbaron: what your saying is if min-width/height are non-auto you'd use them in the aspect ratio?
<gregwhitworth> fantasai: yes
<gregwhitworth> dbaron: there are some weird interactions around this
<gregwhitworth> dbaron: it seems worth trying
<gregwhitworth> dbaron: I think someone should try it before committing
<gregwhitworth> dbaron: I'm worried about web compat
<gregwhitworth> fantasai: this scenario is not a very common case
<gregwhitworth> fantasai: I don't know why you're doing this
<gregwhitworth> dbaron: the main case I can think of is SVG
<gregwhitworth> Rossen: currently that will work
<gregwhitworth> dholbert: in FF that doesn't work
<gregwhitworth> fantasai: so it isn't interoperable right now
<gregwhitworth> fantasai: so...
<gregwhitworth> fantasai: let's give it a try
<gregwhitworth> dbaron: put it into the spec with the note to provide feedback
<gregwhitworth> tantek: we're changing a resolution right?
<gregwhitworth> fantasai: right, from a few months ago
<gregwhitworth> tantek: I'm worried about back compat
<gregwhitworth> tantek: they may have implemented
<gregwhitworth> fantasai: they haven't, that's the point
<AmeliaBR> There are some examples in this pen, if you want to look at current behavior: https://codepen.io/AmeliaBR/pen/brdBvQ
<gregwhitworth> tantek: when we had auto sizing for SVG things we had all kinds of interop issues
<fantasai> s/auto sizing/box sizing/
<gregwhitworth> Rossen: who's going to write the test cases
<tantek> thank you AmeliaBR !
<gregwhitworth> Rossen: I hear some concerns about compat
<tantek> no objection, now that we have a test case to check impls
<gregwhitworth> Rossen: but also given the fact there is no interop on the issue then we should resolve on something that makes more sense
<gregwhitworth> Rossen: any objections?
<gregwhitworth> Rossen: resolved
<gregwhitworth> Rossen: please bring the test cases forward when you start working on the actual text