Re: [css3-background] clarify which properties in this module apply to ::first-letter and ::first-line

On Mar 6, 2012, at 5:31 PM, "Kang-Hao (Kenny) Lu" <kennyluck@csail.mit.edu> wrote:

> CSS2.1 says
> 
> [[
>  The following properties apply to a :first-line pseudo-element: ...
> background properties ... UAs may apply other properties as well.
> ]]
> 
> and
> 
> [[
>  These are the properties that apply to :first-letter pseudo-elements:
> ... border properties ... background properties. UAs may apply other
> properties as well.
> ]]
> 
> although it's not clear what "background properties" and "border
> properties" mean in the context of CSS3 B&B. In particular,
> 'border-radius' is not a subproperty of 'border' and I heard the rumor
> that 'border-radius' should have been called corner-radius so whether it
> belongs to "border properties" is questionable. (I'll assume that
> subproperties of 'background' introduced by CSS3 B&B such as
> 'background-size" count as "background properties" and hence apply to
> both ::first-letter and ::first-line).
> 
> I think the spec should explicitly say that 'border-radius' applies to
> ::first-letter. From testing, Firefox13a, Chromium18 and IE9 but not
> Opera12alpha supports 'border-radius' on ::first-letter (and none of
> them on ::first-line). I have no idea about 'border-image' and
> 'box-decoration-break'.
> 
> (A side question out of curiosity: the spec says
> 
>  # The ¡®box-shadow¡¯ property applies to the ¡®::first-letter¡¯
>  # pseudo-element, but not the ¡®::first-line¡¯ pseudo-element.
> 
> So, does this mean UA MUST NOT apply 'box-shadow' to '::first-line' or
> UA MAY apply 'box-shadow' to '::first-line' (because of CSS2.1) ? )

I don't know what the reasoning was for that. It seems to me that anything which does not affect layout geometry of anything outside itself should be allowed for first line and first letter, and we should say that. This would then include border-radius, box-shadow, text-shadow, border-image, outline, pointer-events, opacity, etc. and maybe even position.

Received on Wednesday, 7 March 2012 22:04:05 UTC