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RE: [css3-flexbox] Flexbox needs to define where the baseline of a box is

From: Alex Mogilevsky <alexmog@microsoft.com>
Date: Wed, 23 Feb 2011 08:58:37 +0000
To: Tab Atkins Jr. <jackalmage@gmail.com>, Boris Zbarsky <bzbarsky@mit.edu>
CC: www-style list <www-style@w3.org>
Message-ID: <D51C9E849DDD0D4EA38C2E539856928411E9DDC2@TK5EX14MBXC212.redmond.corp.microsoft.com>
I am not sure it was quoted in this thread yet, but here is what was decided in Oslo [1]:

   - RESOLVED: Baseline of a flexbox is the baseline of its first
     child. Note: this may be revisited based on use cases. ISSUE-141

It handles most cases of interest, but not the case when the flexbox is completely empty. Then the baseline can only be based on the box.

I am not convinced though that "after outer edge" (border box, right?) as Tab suggested is the best option. I think the baseline should be somewhere in bounds of content box. Then at least some cases retain continuity:
	* adding a zero-height child to flexbox with auto height does not change the baseline
	* baseline of an empty flexbox with "height:1em" is exactly where it would have been if it had a child with one line of text in font with no descent (and no MBP)
	* flexbox padding and border don't affect its baseline, whether it is empty or not.

I am not sure where exactly in content box is the best place for baseline... I think bottom of content box would be a good choice. 

[1] http://lists.w3.org/Archives/Public/www-style/2010Sep/0002.html 

-----Original Message-----
From: www-style-request@w3.org [mailto:www-style-request@w3.org] On Behalf Of Tab Atkins Jr.
Sent: Friday, February 18, 2011 9:16 AM
To: Boris Zbarsky
Cc: www-style list
Subject: Re: [css3-flexbox] Flexbox needs to define where the baseline of a box is

On Fri, Feb 18, 2011 at 9:06 AM, Boris Zbarsky <bzbarsky@mit.edu> wrote:
> The flexbox draft doesn't seem to define where the baseline of a box 
> is located; it certainly doesn't define it for empty boxes.  This 
> needs to be defined.

We agreed on what it should be at the Opera face-to-face, iirc.  (I don't remember exactly what the resolution was, but it was recorded.)

I'm trying to finish up my Flexbox edits right now for a proper new Editor's Draft, and this information will definitely be included.


Received on Wednesday, 23 February 2011 08:59:13 UTC

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