Re: [CSSWG] Minutes and Resolutions Tokyo F2F Fri: CSS2.1, box-shadow and border-image

On Mar 9, 2009, at 1:37 AM, fantasai wrote:

>  dbaron: Brad Kemper vehemently believes that box-shadow should be  
> ignored
>          when border-image is on
>  ...because he thinks they're useful in combination only as fallback

Not to beat an ill horse, but I just wanted to make an additional 2  
points about this:

1. We actually seems to be in general agreement about suppressing box- 
shadow when border-image is on. The differences we have is: some  
people here think it should be off and replaced by a non-box-based  
shadow with the same offsets and blur (automatically generated for  
those images, but not for background images, foreground images, list  
marker images, etc.), and I think it should be off and replaced by  
author controlled images that will be loading anyway. Advantage: more  
control over where the shadows appear or not, and ability to have  
different blur, depth, color, strength etc. of shadow for different  
graphical parts of the images. Disadvantage: the shadows take up space  
(which I have other ideas for dealing with, that I would like to go  
into separately).

The reasons for suppressing the box-shaped shadow are fairly clear (to  
most, I think), and match the reasons for not having border-radius  
clip the border-image: because both those properties assume an outer  
edge shape that is rectangular, but that rectangular shape is not  
relevant when it is based on a suppressed border property and replaced  
by images that can be any shape.

2. Fallback was apparently important in the creation of the border- 
image property, not just to me, but to whoever spec'ed it and agreed  
to its current form. If it was not, we could just say "authors should  
not use border and border-image together, and if they do anyway, one  
will appear in front of the other". So I say, if fallback to border is  
important, it should also be important to be able to fallback to  
things that decorate the same border box which border-image may also  
replace. And certainly rounded corners and shadows are things that  
authors may want to include in their images, and may want to have  
fallbacks for, if we consider fallback to be important (as we seem to  
so far).