W3C home > Mailing lists > Public > www-style@w3.org > May 2010

Re: Questions about 'column-span'

From: David Hyatt <hyatt@apple.com>
Date: Sat, 22 May 2010 23:06:39 -0500
Cc: Håkon Wium Lie <howcome@opera.com>, Bert Bos <bert@w3.org>, "www-style@w3.org list" <www-style@w3.org>
Message-id: <1978C375-FFCD-49A0-BB01-FB740665F123@apple.com>
To: Alex Mogilevsky <alexmog@microsoft.com>
On May 22, 2010, at 5:37 PM, Alex Mogilevsky wrote:

>> -----Original Message-----
>> From: www-style-request@w3.org [mailto:www-style-request@w3.org] On
>> Behalf Of Håkon Wium Lie
>> Sent: Saturday, May 22, 2010 2:38 PM
>> Bert Bos wrote:
>> 
>>>> My own proposal for resolving this would be that [..] column-span  > >
>> can only apply to objects within the same block formatting  > > context as the
>> multicol block. That prevents objects inside  > > overflow:hidden blocks or
>> inline-blocks from being considered.
>>> 
>>> That makes sense. The columns that 'column-span' refers to are those of  >
>> the root of the current block formatting context. (If that root is not  > a multi-
>> column element, then there are no columns to span  > and 'column-span' has
>> no effect.)
>> 
>> Agree.
> 
> This looks like a simplification on the first glance but I have a couple of problems with it:
> 1) This will be the first time "nearest block formatting context parent" is used for anything. It will probably affect the definition of containing block, which is already complex.

I don't think it alters any existing definitions.  This can all be described using existing terminology.

> 2) It is not necessarily a simplification. Column layout already has to handle forced column and page breaks which can occur anywhere. The same code can easily handle column-span: 

I disagree that column and page breaks can actually occur anywhere.  What does it mean for some content inside a table cell to say that it wants to break a column?  Do we really expect that to work?  I sure don't.  Can content inside a float really break a column?  I don't expect that to work either.

I don't think how forced page breaks work has ever been specified in detail, but it definitely isn't the case that implementations honor them just anywhere.  I think we're better off with restrictions, especially at first.  We can always broaden allowed behavior later.

dave
(hyatt@apple.com)
Received on Sunday, 23 May 2010 04:07:16 GMT

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