Re: [css3-background] possibly too late for last call, but: background-opacity?

On Oct 16, 2009, at 10:59 AM, Giovanni Campagna wrote:

> But instead of having individual properties, there could be just one  
> 'apply-effect' property:
>
> apply-effect: opacity, [...];
> apply-effect: drop-shadow, [...];
> apply-effect: clip, [...];
> apply-effect: visibility, [...];
> apply-effect: display, [...];
> apply-effect: left, [...];
> apply-effect: right, [...];
> apply-effect: top, [...];
> apply-effect: bottom, [...];
> apply-effect: z-index, [...];
> apply-effect: overflow, [...];
>
> This would allow the 'apply-effect' property to be easily extended  
> by adding new properties to the list of what effects it would work  
> with. Just substitute the property name as the first argument of the  
> 'apply-effect' value.
>
> Even if implementable, it would create a mess on the author side  
> (nothing else in CSS works like that, shorthand properties reset  
> everything to initial). Definitely better to add an apply-to()  
> functional notation at the end of those properties (commas aside),  
> or at least use an at-rule inside the declaration block (strange,  
> but at least recognizable as different from normal CSS).

This apply-effect: suggestion seems really confusing to me. It's like  
a level of indirection that will make it very hard to track back to  
the rules that affect a particular element, and it's not clear to me  
how you'd animate these effects via CSS transitions and animations.

The simplest approach would be to add new properties for each of the  
layers you want to filter:

border-image-filter: opacity(0.5);

A more conceptual approach would be to think of the part of the  
element that you want to target as part of the selector, though I've  
no idea what the syntax would look like.

Simon