RE: [css3-fonts] opentype font feature support

Monday, March 15, 2010 12:00 PM <tphinney@cal.berkeley.edu>:

>Is it assumed that the effect of "default" can vary between UAs, or is
>the meaning of "default" usually specified by CSS?

Just to add a perspective to the question, but not answer it: when I specify
"normal" (what you're calling "default") for a particular property, in my
mind I'm explicitly instructing the UA to do what I would normally *expect*
it to do if it supports that property. More specifically, I would expect any
UA that supports kerning to apply it as a matter of course, with no explicit
"font-kerning:normal" being necessary unless the HTML element is inheriting
"font-kerning:none" from a parent element, or some similar situation.
However, in an earlier post, Robert O'Callahan reported:
>By default, Firefox will apply kerning for font sizes at or over a certain
threshold (20 device pixels, currently).
In other words, there is a threshold of 20 device pixels in place, below
which the equivalent of "font-kerning:none" takes effect.
Will other UA's automatically follow suit? Should they? Don't know. But to
ensure that UA's consistently meet author's expectations the question seems
to be: does "the meaning" of default/normal need to be more tightly defined?
As to your original question, I too am curious as to what the general
approach is in CSS regarding how much should be left to the discretion of
the UA and how much not. Especially with something as fundamental as text
rendering.

Regards,

Rich

-----Original Message-----
From: www-style-request@w3.org [mailto:www-style-request@w3.org] On Behalf
Of Thomas Phinney
Sent: Monday, March 15, 2010 12:00 PM
To: John Daggett
Cc: Christopher Slye; www-style
Subject: Re: [css3-fonts] opentype font feature support

On Sun, Mar 14, 2010 at 11:52 PM, John Daggett <jdaggett@mozilla.com> wrote:
> The keyword 'normal' is commonly used in CSS to indicate 'default', it's
> the value a property will typically assume when it's not specified
> explicitly.  I realize 'default' might seem more natural to some but
> consistency with other CSS properties is important.

Is it assumed that the effect of "default" can vary between UAs, or is
the meaning of "default" usually specified by CSS?

Regards,

T

-- 
"The rat's perturbed; it must sense nanobots! Code grey! We have a
Helvetica scenario!" — http://xkcd.com/683/

Received on Monday, 15 March 2010 17:28:57 UTC