W3C home > Mailing lists > Public > www-style@w3.org > February 2012

Re: [css3-images] Probably editorial: 'object-fit' values 'cover' and 'contain' contain redundant definition

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 21 Feb 2012 18:06:48 -0800
Message-ID: <CAAWBYDCWL5ryQ21GwViXj3+rFaayPP3hOjyTaPz+3_YFqa06bg@mail.gmail.com>
To: Leif Arne Storset <lstorset@opera.com>
Cc: "www-style@w3.org" <www-style@w3.org>
On Thu, Feb 2, 2012 at 4:12 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
> On Wed, Feb 1, 2012 at 7:07 AM, Leif Arne Storset <lstorset@opera.com> wrote:
>> In section 5.4, both 'contain' and 'cover' seem to be defined twice. For
>> example, 'contain' says
>>
>> | Determine the used ‘height’ and ‘width’ of the element as usual, except:
>> | If both ‘height’ and ‘width’ are ‘auto’, and the used value of at least
>> | one of ‘max-width’ and ‘max-height’ is not ‘none’, then compute the
>> | element's used width and used height as though the intrinsic dimensions
>> | of the contents were infinitely large numbers whose ratio is the actual
>> | intrinsic ratio of the contents. This will proportionally scale the used
>> | width and height up to the given maximum constraints.
>> |
>> | Set the concrete object size to the largest width and height that has
>> | the same aspect ratio as the object's intrinsic aspect ratio, and
>> | additionally has neither width nor height larger than the replaced
>> | element's used width and height, respectively.
>>
>> These seem redundant to me. I suspect the first definition, written in
>> 2007, hails from a time when '(max|min)-(width|height)' were underdefined
>> in level 2, and "as usual" wasn't sufficient. [0] Determining used values
>> for 'width' and 'height' seems out of scope for this property and this
>> spec, as implied by the introduction to 5.4:
>>
>> | The ‘object-fit’ property specifies how the contents of a replaced
>> | element should be scaled relative to the box established by its used
>> | height and width.
>>
>> I could be wrong: my head is spinning from trying to calculate
>> some examples according to both the specs. If I am wrong, and some
>> situation does require all the infinity math, I feel we could phrase it
>> more simply and/or state the covered cases more clearly.
>>
>> My primary suggestion, however, is to delete the first paragraph, both
>> under 'contain' and 'cover', so that both consist only of a paragraph
>> starting with "Set the concrete object size…".
>>
>> [0] At the moment I can't find old versions of CSS 2.1, but CSS 2 does not
>> define it as well as CSS 2.1.
>> CSS 2:
>> http://www.w3.org/TR/2008/REC-CSS2-20080411/visudet.html#min-max-widths
>> CSS 2.1: http://www.w3.org/TR/CSS21/visudet.html#min-max-widths
>
> Nope, it's not redundant.  Those first paragraphs have the effect of
> forcing the size of the element itself to the min/max constraint.
>
> I agree that this is out-of-scope for this property.  Fantasai does not.

Since I rejected this feedback, could you indicate whether you're okay
with this resolution or not, Leif?  This is necessary for the
Disposition of Comments.

~TJ
Received on Wednesday, 22 February 2012 02:07:39 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:51 GMT