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Re: [css4-images] specifying intrinsic size for images that haven't loaded yet

From: L. David Baron <dbaron@dbaron.org>
Date: Sat, 28 Jul 2012 22:21:16 -0700
To: Alan Gresley <alan@css-class.com>
Cc: www-style@w3.org
Message-ID: <20120729052116.GA25629@crum.dbaron.org>
On Sunday 2012-07-29 15:08 +1000, Alan Gresley wrote:
> On 29/07/2012 2:22 PM, L. David Baron wrote:
> 
> >http://www.jwz.org/blog/2012/07/non-bouncy-layouts/ describes a use
> >case that we should try to address; specifying an *intrinsic size*
> >for images that aren't loaded yet so that pages don't bounce around
> >when images load.  This is doable today if you want the images to be
> >sized to their intrinsic size, but it's not doable today if you want
> >to scale the images but preserve the intrinsic ratio (for example,
> >by making them the width of their container).
> 
> I believe this is what the value 'fill' does with the property
> 'object-fit' by this algorithm (see point two for 'specified size')
> [2].

This is not possible, since 'fill' is the initial value of
'object-fit', so it must be compatible with today's behavior.  And
today's behavior (per CSS 2.1) is that given something like:

  <img src="..." width="1500" height="1000" style="width: 100%">

in an 800px wide container, the image will end up being 800px wide
and 1000px tall, rather than 600px tall.

If the height="1000" is omitted, then there's no knowledge of the
intrinsic dimensions prior to the image starting (at least) to load.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                           http://www.mozilla.org/   𝄂
Received on Sunday, 29 July 2012 05:21:44 GMT

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