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Re: Control over collapsing margins

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 28 Apr 2009 10:02:35 -0500
Message-ID: <dd0fbad0904280802k2d42c312m44458246641a595d@mail.gmail.com>
To: Niels Matthijs <niels.matthijs@internetarchitects.be>
Cc: www-style@w3.org
On Tue, Apr 28, 2009 at 9:50 AM, Niels Matthijs
<niels.matthijs@internetarchitects.be> wrote:
> -----Original Message-----
> From: Giovanni Campagna [mailto:scampa.giovanni@gmail.com]
> Sent: 28 April 2009 16:39
> To: Niels Matthijs
> Cc: www-style@w3.org
> Subject: Re: Control over collapsing margins
>
>> Of course it is a hack, but at least it works most of time.
>
> I think, with column modules, SVG graphics, css animation and
> multibg/rounded-corner boxes in the making that we shouldn't just be
> content with hacking our way across margins anymore. It's one of the
> most basic css properties and important for a solid page structure. I'd
> hope to use it when css3 support is there without needed to hack my way
> around a simple thing like this.
>
>> On the other side, I don't see the necessity for "margin-top-collapse"
>> / "margin-bottom-collapse" or even just "margin-collapse" (since we
>> need margin-left-collapse and margin-right-collapse for Japanese and
>> Mongolian)
>
> It is useful from time to time. Meyer gave a good example of p's nested
> in a li element (where the top of the first paragraph should line up
> with the top of the li element if it isn't visually separated.
>
> Not quite sure if a BFC is such a good idea, since this seems to involve
> more than simply controlling the collapsing margin, and could have
> unwanted effects?

Well, in my experience the major effects of creating a BFC are that
margins won't collapse through them, they contain their descendant
floats, and they won't overlap sibling floats.  I use them (typically
through the overflow hack) regularly in my designs for all of those
reasons.

Does anyone know of any other 'standard features' of BFCs that I'm missing?

~TJ
Received on Tuesday, 28 April 2009 15:03:11 GMT

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