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Re: [css3-background] box-shadow syntax

From: Alan Gresley <alan@css-class.com>
Date: Sat, 10 May 2008 10:09:27 +1000
Message-ID: <4824E7B7.9030200@css-class.com>
To: Eli Morris-Heft <dai@doublefishstudios.com>
CC: Brad Kemper <brkemper@comcast.net>, "www-style@w3.org list" <www-style@w3.org>

Eli Morris-Heft wrote:
> Alan Gresley wrote:
>> 0px 0px 0px 4px blue
>>
>> What does the third value do?
> 
> The third value is blur radius, as it currently is in the spec. The 
> fourth value is Brad's proposed 'spread' width.


Ops, sorry, I should have said what is the fourth value?


>> For me a minus value is no value at all if we are talking about a 
>> width. Having a -4px width doesn't sound right and can be mixed up 
>> with minus (x/y) positions of a shadow.
>> /* ...snip... */
>> What we were initially talking about is glow, blur or inner.
> 
> I thought what we were initially talking about was a shadow, not a glow...


Well of course we talking about shadow, text-shadow and box-shadow. What 
I am suggesting is what type of shadow it is. Does it show a graduation? 
Is it pixelated or smooth?. Does it suggest graduation to emulate depth 
of field (perspective)? It it neon, glow, electric (suggesting energy). 
All is it misty, foggy, ghostly (suggesting movement)?


What could be possible by implementation in 2020?


Do we just have now for CSS the first case.

box-shadow: 0 0 blue;
box-shadow: 0 0 ? blue;


An implementation that only support shadow offset will only use the 
first declaration and throw out the second declaration since it has four 
values. Future implementations could use either declaration, the second 
one with value (?) allowing for progressive enhancement in CSS4.

I can see this getting out of hand already (let's consider the 
consequences). I believe that all extra inner, outer and whatever values 
should appear last as.


box-shadow: 0 0 blue ?;


since an implementation supporting an extra values as

box-shadow: 0 blue ?;


will be considered by an implementation as.

box-shadow: 0 0 blue ?;


Any non supporting implementation would throw the declaration out.


Alan
Received on Saturday, 10 May 2008 00:10:19 GMT

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