Re: Shadows vs. layout

On Aug 3, 2009, at 3:14 PM, fantasai wrote:

> 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.
>
> Ok, by trigger overflow I mean trigger scrolling. Content that  
> overflows
> a box doesn't affect the layout of elements outside the box, except
> insofar as it triggers scrolling behavior.

Well, I would think that if it is not affecting the layout/size of  
elements outside of itself, then it would also not affect the size  
layout of such element even if it was a BODY element or viewport.  
Ergo, it's parent would not be larger as a result, and would therefore  
not need to scroll anyway if it didn't before. Is not the scroll bar  
appearing as the result of some parent element getting wider? ANd if a  
parent element can get wider because of the overflow of a shadow or  
outline or border-image, then it can affect layout. That's the point I  
was trying to make, so correct me if there is some logical flaw to my  
argument that I am missing, please.

>> 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.
>
> Why would you do something like that?

Perhaps I have a border that is used in more than one way, at  
different scales, with a shadow built into it. If I put it on the  
body, Perhaps the strongest part of the image is a 2px line that would  
fall 8px outside of the padding, and most of what is outside that is a  
very light, very blurry shadows or glows on some images that are tiled  
on the right and left sides. I don't want them to cause scrolling (its  
not important to for people to have to scroll to see the outside edge  
of a blur), but I might want to use the border-image in other places  
too, where the blurred edge is not cut off by the viewport.