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Re: [CSS21] Distinguishing block boxes, block containers, and block-level elements

From: Alan Gresley <alan@css-class.com>
Date: Thu, 19 Aug 2010 18:04:29 +1000
Message-ID: <4C6CE58D.2040106@css-class.com>
To: Peter Moulder <peter.moulder@monash.edu>, "www-style@w3.org" <www-style@w3.org>
Peter Moulder wrote:
> On Tue, Aug 17, 2010 at 07:30:17PM -0700, fantasai wrote:
> 
>> Section 8.3.1 Collapsing margins
>>
>>     # Two or more adjoining vertical margins of block boxes in the normal
>>     # flow collapse.
>>
>>     s/block boxes/block-level box/
> 
> (Of course you mean plural.)
> 
> 
>>     | Non-replaced inline blocks,
>>     | table cells, and table captions are also block container boxes,
>>     | but are not block-level boxes.
> 
> That sentence has a parsing ambiguity as to whether "non-replaced" associates
> just with inline blocks or with all of those things; I suggest "Inline blocks,
> table cells, ... are also block container boxes (unless they are replaced
> boxes)".
> 
> 
> It surprises me that we want table captions not to be block-level boxes given
> that their behaviour seems very much like a block-level box (once the anonymous
> table wrapper box has been generated, at least).
> 
> Out of curiosity, what rule(s) concerning block-level boxes are we trying to
> avoid here, or what's the reason for choosing for them not to be block-level ?
> 
> Note that section 17.4 currently explicitly says "caption boxes are block-level
> boxes", which would conflict with this text.
[snip]


If the caption boxes not considered block-level boxes then the 
anonymous table wrapper box that is generated has to be a "block-level 
box" but this would mean that tables would not behave as "shrink to 
fit boxes".

This is why I presume that section 17.4 currently says "caption boxes 
are block-level boxes". From a designer perspective, caption boxes are 
hard to style since margins do not work in all implementations. Also, 
even though captions are like headings for tables, they don't behave 
as headings.

On a side note, what is a "block container box"? This could get 
confused with a "containing block".


-- 
Alan http://css-class.com/

Armies Cannot Stop An Idea Whose Time Has Come. - Victor Hugo
Received on Thursday, 19 August 2010 08:05:01 GMT

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