W3C home > Mailing lists > Public > public-respimg@w3.org > December 2016

Re: aspect ratio as an attribute

From: <steve@steveclaflin.com>
Date: Fri, 16 Dec 2016 08:46:19 -0600
To: Yoav Weiss <yoav@yoav.ws>
Cc: Adam van den Hoven <adam@littlefyr.com>, Simon Pieters <simonp@opera.com>, Greg Whitworth <gwhit@microsoft.com>, Tommy Hodgins <tomhodgins@gmail.com>, "Hall, Charles (DET-MRM)" <Charles.Hall@mrm-mccann.com>, public-respimg@w3.org, Jason Grigsby <jason@cloudfour.com>, Paul Deschamps <pdescham49@gmail.com>, alex@bellandwhistle.net, Jonathan Kingston <jonathan@jooped.co.uk>
Message-ID: <347e2ef8e22441cbc830772745d52ee9@steveclaflin.com>
Totally agree with this perspective.  To complete what may be implied, 
in picture each separate source could have it's own aspect, but I would 
then say that every url listed in the srcset for one source should share 
that aspect value.

As a separate note, to avoid developer confusion between initial layout 
hints (HTML) with required layout behavior (CSS), maybe the attribute 
should be something that indicates its nature, like aspect-hint, 
expected-aspect, native-aspect, or something else slightly more verbose 
but clearer.

On 2016-12-16 00:17, Yoav Weiss wrote:
> On Thu, Dec 15, 2016 at 11:49 PM Adam van den Hoven
> <adam@littlefyr.com> wrote:
> 
>> srcset also poses a problem (there's no reason to expect that a
>> particular sized resource has the same aspect ratio as the rest) but
>> if the aspect-ratio that alex proposed only describes the aspect
>> ratio of the resource in src, an add aspect-ratio-set that matches
>> src values in src set with an aspect ratio, we'd have a consistent
>> solution. the hyphation in the attribute names are a pain so i'd use
>> aspect and aspectset
> 
> That's really not required. There is reason to expect all resources
> inside of srcset are of the same aspect ratio, as they are supposed to
> be interchangeable, differing from one another only in dimensions and
> density (and potentially compression quality). The browser can pick
> one or the other based on heuristics. If you have different aspect
> ratios for resources in different dimensions, you should use picture.
> 
>> So I'm suggesting (starting from the Mozilla docs on img [1]):
>> 
>> <img src="clock-demo-thumb-200.png"
>> aspect="0.75"
>> alt="Clock"
>> srcset="clock-demo-thumb-200.png 200w,
>> clock-demo-thumb-400.png 400w, clock-demo-thumb-unknown.png 500w"
>> aspectset ="0.75, 1, default"
>> sizes="(min-width: 600px) 200px, 50vw">
>> 
>> The logic being, if only aspect-ratio exists, it applies to all the
>> src values (src and srcset). If defined aspect-ratio-source only
>> applies to the srcset items. the default keyword is "we don't know
>> what it its", ie the current behaviour. If there are more srcset
>> values than aspectset values, either apply the last value, or the
>> aspect value or maybe start over from the first and apply them in
>> turn. Not sure what's best. (I'm agnostic about implying computation
>> with 4/3 vs 1.333)
>> 
>> But that's possibly making it a LOT more complex than necessary?
> 
> Yup
> 
> Links:
> ------
> [1]
> https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#Example_4_Using_the_srcset_and_sizes_attributes
Received on Friday, 16 December 2016 14:46:54 UTC

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