Re: [CSS21] 10.1 Containing block: when "the ancestor is an inline element": editorial improvements

> On 8/03/2012 4:10 PM, "Gérard Talbot" wrote:
>> Hello,
>>
>> Section 10.1, bullet 4 (with sub-bullets 1 and 2)
>> http://www.w3.org/TR/CSS21/visudet.html#containing-block-details
>>
>> Current text is:
>>
>> {
>> 4. If the element has 'position: absolute', the containing block is
>> established by the nearest ancestor with a 'position' of 'absolute',
>> 'relative' or 'fixed', in the following way:
>>
>>    1.  In the case that the ancestor is an inline element, the
>> containing
>> block is the bounding box around the padding boxes of the first and the
>> last inline boxes generated for that element. In CSS 2.1, if the inline
>> element is split across multiple lines, the containing block is
>> undefined.
>>    2.  Otherwise, the containing block is formed by the padding edge of
>> the
>> ancestor.
>> }
>>
>>
>> Proposed replacement (the pairs of ** indicate where editorial changes
>> would be):
>>
>> {
>> 4. If the element has 'position: absolute', the containing block is
>> established by the nearest ancestor with a 'position' of 'absolute',
>> 'relative' or 'fixed', in the following way:
>>
>>    1. *In case such nearest positioned ancestor is an inline element,
>> then*
>> the containing block is the bounding box around the padding boxes of
>> the first and the last inline boxes generated for that element. In CSS
>> 2.1, if the inline element is split across multiple lines, the
>> containing
>> block is undefined.
>>
>>    2. *In case such nearest positioned ancestor is a block container,
>> then*
>> the containing block is formed by the padding edge of such block
>> container.
>> }
>>
>>
>> What can definitely create confusion and misinterpretation is this
>> proposition:
>> "In the case that the ancestor is an inline element (...)"
>> when the proposition should at least explicitly identify such ancestor
>> as
>> "the nearest positioned ancestor".
>>
>> Gérard
>
> Gérard, there is confusion in that part of the testsuite (test that are
> not testing what they purport to test) and section 10.1.

>
>    (IE9, Safari 5.1.2 and Opera 11.61 pass)
>
>
> To follow what that test is testing, examine a simpler test.
>
>    (IE9, Safari 5.1.2 and Opera 11.61 pass ltr)
>    (IE9 and Safari 5.1.2 pass rtl)
>
> http://css-class.com/test/temp/containing-block-inline.htm

>
> Note how the wording of section 10.1, point 4.1 has changed:
>
> Current:
>
>    | In the case that the ancestor is an inline element,
>    | the containing block is the bounding box around the
>    | padding boxes of the first and the last inline boxes
>    | generated for that element. In CSS 2.1, if the inline
>    | element is split across multiple lines, the
>    | containing block is undefined.
>
> Previous:
>
> http://www.w3.org/TR/2010/WD-CSS2-20101207/visudet.html#containing-block-details
>
>    (note that this is point 4.1.1)
>
>    | If the 'direction' is 'ltr', the top and left of the
>    | containing block are the top and left padding edges
>    | of the first box generated by the ancestor, and the
>    | bottom and right are the bottom and right padding
>    | edges of the last box of the ancestor.
>
>    | Note: This may cause the containing block's width
>    | to be negative.
>
>
> Some history on these test and the testsuite regarding 10.1.
>
> http://lists.w3.org/Archives/Public/public-css-testsuite/2010Dec/0203.html
>
> And a familiar looking test below which is identical to
> containing-block-011.htm apart from the assert.
>
> http://test.csswg.org/suites/css2.1/20101027/html4/containing-block-017.htm