Re: [css-images] Overconstrained image sizing and preserving aspect ratio: the object-sizing property

On Sun Feb 09 2014 at 5:17:14 PM, Dean Jackson <dino@apple.com> wrote:

>
> On 7 Feb 2014, at 3:07 pm, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
>
> > On Fri, Feb 7, 2014 at 2:32 PM, Edward O'Connor <eoconnor@apple.com>
> wrote:
> >>> I'm fine with "prefer-intrinsic", or something similar, for the one
> >>> that just upgrades the power of an intrinsic aspect ratio.
> >>
> >> Dean keeps typing "preserve-intrinsic," which might be a hint that
> >> "preserve" is a better term than "prefer." *shrug*
> >
> > I'm thinking that we want the keyword for intrinsic AR and the keyword
> > for calculated AR from width/height to be similar, and there's nothing
> > to "preserve" in the latter.
> >
> > Let's stick with the image-resolution:from-image precedent, and do
> > "from-intrinsic" and "from-dimensions" (or "from-size"?) as the two
> > keywords?
>
> First up, let me apologize for sending an email about CSS to the
> www-shadow-dom-fighting list.
>
> I’ve got an implementation of this aspect-ratio/object-sizing thing mostly
> working (and it improves the cases we were hitting, so I’m fairly happy).
> Now I need an actual specification to conform to, and I think it might
> require a fair amount of patchwork into the existing CSS layout specs.
>
> Tab, are you willing to expand your official blog post on aspect-ratio
> into something on dev.w3.org?
>
> I think we’re agreed on:
>
> 1. Adding aspect-ratio: from-intrinsic; (and from-dimensions or from-size)
> 2. Having this value somehow interrupt the typical sizing algorithm to
> value the aspect-ratio over other sizing contraints (this is where it gets
> tricky, and will probably require a lot of review)
>
> I’ve only implemented this for replaced elements, but I’m fine with it
> applying to everything, as long as someone writes the spec.
>
> My current implementation is intentionally hacky, because I was trying to
> see if the behaviour was useful. I apply an override after the existing
> layout has happened, and reduce either width or height until we meet the
> specified aspect ratio. This means you can end up with something that is
> sized smaller than min-width or min-height, but Tab’s blog post says that
> you should just ignore the aspect-ratio property in this case (do we really
> want this?)
>

My blog post should *not* be followed.  It was written early in my speccing
career, and it doesn't actually make much sense.

I'm happy to redefine 'aspect-ratio', and put it in the Sizing module.

~TJ