W3C home > Mailing lists > Public > www-style@w3.org > August 2009

Re: Shadows vs. layout

From: David Hyatt <hyatt@apple.com>
Date: Mon, 03 Aug 2009 18:08:03 -0500
Cc: fantasai <fantasai.lists@inkedblade.net>, W3C style mailing list <www-style@w3.org>
Message-id: <CA9E33B6-239D-4406-AA71-8FFDD60CC1BE@apple.com>
To: Brad Kemper <brad.kemper@gmail.com>
On Aug 3, 2009, at 5:58 PM, Brad Kemper wrote:

>
>
> On Aug 3, 2009, at 1:45 PM, fantasai <fantasai.lists@inkedblade.net>  
> wrote:
>
>> Brad Kemper wrote:
>>> Sent from my iPhone
>>> On Aug 3, 2009, at 1:08 PM, fantasai  
>>> <fantasai.lists@inkedblade.net> wrote:
>>>> I'm not sure about border-image outside the border area, whether  
>>>> that should
>>>> trigger scrolling or not. I'm leaning towards leaving the  
>>>> standard behavior.
>>>> But shadows definitely should not trigger scrolling.
>>> I don't have the link handy, but in that write-up I did a while  
>>> back explaining how the border-images should not take up space, I  
>>> think many of the use cases and examples I gave would not work  
>>> well at all if they pushed container dimensions to the right and  
>>> bottom. A central idea was that page geometry would be the same  
>>> with or without the border-image.
>>
>> Well, yes, the outset shouldn't affect layout. But whether it should
>> trigger overflow is another issue.
>
> Overflow does affect layout, doesn't it? If my image bordered  
> element is inside another element that is floated, then the width of  
> the floated element changes based on whether or not the overflow  
> from the border-image is widening it or not. That then affects what  
> other elements can sidle up alongside it.
>
> Also, suppose my BODY element has 16px of padding and no margin or  
> border. Now I put a 32px wide border-image around it with a 32px  
> offset. In that case, I would expect the border-image to be clipped  
> on all four sides (or at least three). If it was clipped on the left  
> and top but scrollable to the right and bottom, that would just be  
> weird.

That oddity already exists with all scrollable overflow.  Make an  
absolute positioned element with a negative top/left and a right/  
bottom that goes out past the bottom right edge of the container.   
You'll see that you can't scroll to reveal the top/left corner of the  
object but will be able to reveal the right/bottom.

I would not get too hung up on this, as it has more to do with user  
agents not having a decent model for scrolling to reveal the top/left  
area without putting the scrollbar at a bizarre position to start.  I  
don't think it's particularly relevant to the discussion, since this  
bizarre behavior is just part of all scrollable overflow.

In fact Web sites even deliberately hide elements offscreen using  
large negative left/top values, so we couldn't scroll to reveal this  
stuff at this point even if we wanted to. :)

dave
(hyatt@apple.com)
Received on Monday, 3 August 2009 23:08:45 GMT

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