Re: [css3-background] background-shorthand and its background-clip side-effect

On Mar 5, 2010, at 8:15 AM, Tab Atkins Jr. wrote:

> On Fri, Mar 5, 2010 at 10:00 AM, Brad Kemper <brad.kemper@gmail.com> wrote:
>> 
>> On Mar 5, 2010, at 7:52 AM, Tab Atkins Jr. wrote:
>> 
>>> On Thu, Mar 4, 2010 at 2:36 PM, Brad Kemper <brad.kemper@gmail.com> wrote:
>>>> On it's own it not too bad, but as a way to disambiguate between two
>>>> subproperties in in 'background' that take the same values, it is
>>>> inconsistent with any of the proposals to disambiguate <bg-position> and
>>>> <bg-size>.  I don't think this serves authors as well, ultimately, who
>>>> currently have no expectations of how this disambiguation should occur.
>>> 
>>> The position/size disambiguation needs to be more complex, because
>>> there is added possibility of confusion.  Both properties can have one
>>> or two value, so if you see two lengths next to each other, you can't
>>> tell whether it's just one property being specified or two being given
>>> a single value.  Similarly, if you see 3 values you can't tell which
>>> property gets a pair and which gets a singleton.
>> 
>> You can if you use the slash the way I was suggesting, which would also be consistent between disambiguating BOTH the <bg-position>/<bg-size> combinations AND the <bg-origin>/<bg-clip> combinations in the same ways. Thus, the position/size disambiguation does NOT need to be more complex than the origin/clip disambiguation. They can both be simple, with a single slash providing a reference point for disambiguation.
> 
> What I meant is that you don't *need* a slash in the origin/clip
> situation, since you can rely on a simple ordering.  That's not
> sufficient for position/size.  Ordering-based disambiguation is used
> much more commonly throughout CSS, and so should be relied on when
> possible.

Right, but the part you quoted me on was about how the two situations are not consistent with each other, but could be (very simply). My way is still ordering-based; the order is in relation to the slash.