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Re: [CSS21] Objection over Issue 203 (clearance and hypothetical position) (Was: Re: [CSS21] Clearance - the missing manual)

From: Bert Bos <bert@w3.org>
Date: Fri, 25 Mar 2011 22:00:54 +0100
To: "www-style@w3.org" <www-style@w3.org>
Message-Id: <201103252200.54213.bert@w3.org>
On Thursday 24 March 2011 21:37:20 fantasai wrote:
> On 03/24/2011 01:24 PM, fantasai wrote:
> > Ok, Arron and I spent some time on the phone trying to figure out
> > what Issue 203 actually is, and we think we understand the problem
> > Anton is describing.
> > ...
> > The proposal is to replace
> > # the element had a non-zero bottom border and its 'clear' property
> > with
> > 
> > | the element's 'clear' property
> 
> While we're in this section, Arron and I noticed that the first
> paragraph of the first clearance example is self contradicting (B2
> has no children, but is not empty?)

You two have been reading too much CSS2 lately. :-)

An element with text content also isn't empty, as Řyvind already said.

> and involves more complication
> than need be (the possibility of self-collapsing margins due to no
> padding, no border, and no children):

No, B2 has content, it cannot collapse through.

> 
>    # Example 1. Assume (for the sake of simplicity), that we have
> just # three boxes, in this order: block B1 with a bottom margin of
> M1 # (B1 has no children and no padding or border), floating block F
> # with a height H, and block B2 with a top margin of M2 (no padding
> # or border, no children). B2 has 'clear' set to 'both'. We also #
> assume B2 is not empty.
> 
> Here's a suggested replacement:
>    | Example 1. Assume (for the sake of simplicity), that we have
>    | just three boxes, in this order: block B1 with *a bottom border
>    | and* a bottom margin of M1, floating block F with an *outer*
>    | height H, and block B2 with *a top border and* a top margin of
>    | M2. B2 has 'clear' set to 'both'.

Sure, the same computation applies when B2 has a top border instead of 
content, but having content is more common.

Why the border on B1?

> 
> Also, this sentence was very confusing:
>    # We need to compute clearance C twice, C1 and C2, and keep the
>    # greater of the two: C = max(C1,C2).
> 
> I suggest replacing "twice" (which isn't what really happens) with
> 
> "as two separate calculations", thus:
>    | We need to compute clearance C as two separate calculations, C1
>    | and C2, and keep the greater of the two: C = max(C1,C2).

"Twice" seems rather shorter and easier to understand.



Bert
-- 
  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos                               W3C/ERCIM
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France
Received on Friday, 25 March 2011 21:01:22 GMT

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