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Re: [CSS21] Disposition of Comments (Issue 225, 229 etc)

From: fantasai <fantasai.lists@inkedblade.net>
Date: Thu, 07 Apr 2011 10:38:42 -0700
Message-ID: <4D9DF6A2.1010101@inkedblade.net>
To: Anton Prowse <prowse@moonhenge.net>
CC: "www-style@w3.org" <www-style@w3.org>
On 04/07/2011 12:18 AM, Anton Prowse wrote:
>>
>> | If the element has children, its height is the distance from its top content
>> | edge to the first applicable of the following:
>> | * the bottom edge of the last line box, if the box establishes a inline
>> | formatting context with one or more lines
>> | * the bottom edge of the bottom collapsed margin of its last child,
>> | if the child's bottom margin does not collapse with the element's
>> | bottom margin
>> | * the bottom border edge of its last child, if the child's bottom
>> | margin collapses with the element's bottom (but not with its top)
>> | margin
>> | * zero, otherwise
>>
>> Would this solve the issues?
>
> Sorry, that's not going to work either. The text must take into account
> that the last child might be self-collapsing and collapse with the element's
> bottom margin, in which case it's the last /non/-self-collapsing child which
> is going to dictate the element's height. I believe that my proposal in [1]
> is technically correct.
>
> [1] http://lists.w3.org/Archives/Public/www-style/2011Feb/0492.html

Yeah, but I've read your proposal at least 5 times now, and I still
can't really make sense of it. So I don't really want to put it in
the spec, even if I trust it's correct. :)

Now that I understand what the problematic situation is, let me try
again.

   | If the element has children, its height is the distance from its top content
   | edge to the first applicable of the following:
   |   * the bottom edge of the last line box, if the box establishes a inline
   |     formatting context with one or more lines
   |   * the bottom edge of the bottom collapsed margin of its last child,
   |     if the child's bottom margin does not collapse with the element's
   |     bottom margin
   |   * the top edge of its bottom collapsed margin, if the last child's
   |     bottom margin collapses with the element's bottom (but not with
   |     its top) margin
   |   * zero, otherwise

Does this work?

> How about:
>
> | But in CSS 2.1, if there is a line box, in-flow block or floated
> | box that would constrain the position of the float through the
> | application of rules 5 and 6 but which would not constrain it if
> | certain in-flow vertical negative margins within the block
> | formatting context were set to zero, then position of the float is
> | undefined.

I think at this point we'd have to defer such a change to errata.

> I can't accept the wording in the current pre-PR Editor's Draft, since it doesn't match the proposal in the Issues Wiki and
> hence doesn't even fully encompass the problematic cases. Specifically, the Wiki proposal is "... were all such negative
> margins were set to zero", whereas the ED is "... were the negative margin set to zero". The cumulative effect hinted at by
> the Wiki proposal is important:

Ugh, good catch. Yes, we absolutely need to fix that. I'll tell
Bert to regenerate the draft...

~fantasai
Received on Thursday, 7 April 2011 17:39:13 GMT

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