W3C home > Mailing lists > Public > www-style@w3.org > November 2011

Re: [CSS21] Question on section 9.5.1 Positioning float: error in sentence

From: Anton Prowse <prowse@moonhenge.net>
Date: Sun, 27 Nov 2011 15:46:05 +0100
Message-ID: <4ED24D2D.2050602@moonhenge.net>
To: www-style@w3.org
CC: www-style@gtalbot.org
On 08/11/2011 18:20, "Gérard Talbot" wrote:
> Le Mar 8 novembre 2011 5:24, Anton Prowse a écrit :
>> On 08/11/2011 01:55, "Gérard Talbot" wrote:
>>> I've read the following sentence at least 20 times and I think there's
>>> several small mistakes which can compromise comprehension.
>>>
>>> "
>>> But in CSS 2.1, if, within the block formatting context, there is an
>>> in-flow negative vertical margin such that the float's position is above
>>> the position it would be at were all such negative margins set to zero,
>>> the position of the float is undefined.
>>> "
>>> http://www.w3.org/TR/CSS21/visuren.html#floats
>>>
>>> I think such sentence should be stating instead
>>>
>>> "
>>> But, in CSS 2.1, if, within the block formatting context, there is an
>>> in-flow negative vertical margin such that the float's position is above
>>> the position it would be at if such negative vertical margin was set to
>>> zero, then the position of the float is undefined.
>>> "
>>

>> Secondly, I think the sentence in the spec is a little strange but it's
>> grammatically OK.  If "there is an" were replaced with "there is one or
>> more" then the intent would be completely clear.
>
> I have read such sentence again (along with your explanation) and still do
> not feel that ordinary web authors are going to understand it like you
> interpret it.

I originally thought you were taking issue with the grammar of this 
sentence.  On reading your response and your original post again, I 
think you're actually asking what the sentence means conceptually. Sorry 
for misunderstanding you.

I agree with you that the sentence doesn't work, editorially speaking. I 
raised this as a concern[1] on Issue 229.  If it intends to say that the 
position of a float is undefined when a source-preceding box has a 
negative vertical margin, then it should just say something like that. 
If, instead, it's trying to restrict the vertical margins under 
consideration in order to focus more closely on the specific issues of 
Issue 229 then it's flawed because it doesn't solve the problem as 
currently written.  (When the position of the float is calculated with 
the specified negative margins then at least Rule 6 needs to be ignored.)

This will definitely need cleaning up in CSS3.

[1] http://lists.w3.org/Archives/Public/www-style/2011Mar/0403.html

Cheers,
Anton Prowse
http://dev.moonhenge.net
Received on Sunday, 27 November 2011 14:46:47 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:46 GMT