[css3-fonts] Addition of font-size: xxx-large

CSS 3 Fonts, like CSS 2.1, defines <absolute-size>s ranging from
xx-small to xx-large.  The legacy HTML <font size=1> corresponds to
xx-small, 2 is small (skipping x-small), and 3-6 are medium to
xx-large.  There is no CSS equivalent to <font size=7> -- 3rem is
different because it varies if you change the root element's font
size.  I would like to request that a "font-size: xxx-large" value be
defined, corresponding to <font size=7> (scaling factor of 3).

WebKit already supports "font-size: -webkit-xxx-large".  Both HTML5
and HTML Editing APIs refer to a nonexistent CSS value of "xxx-large":

"The 'xxx-large' value is a non-CSS value used here to indicate a font
size 50% larger than 'xx-large'."
http://dev.w3.org/html5/spec/rendering.html#phrasing-content-1

"""
If command is "fontSize"; and new value is one of "xx-small", "small",
"medium", "large", "x-large", "xx-large", or "xxx-large"; and either
the CSS styling flag is false, or new value is "xxx-large": . . .
"""
http://dvcs.w3.org/hg/editing/raw-file/tip/editing.html#force-the-value

The lack of xxx-large causes significant problems for editing (in the
sense of <http://dvcs.w3.org/hg/editing/raw-file/tip/editing.html>).
Rich-text editing commands (document.execCommand()) can create styles
using either CSS or HTML tags.  The fontSize editing command accepts 1
to 7 as parameters, because it was designed before CSS was commonly
supported.  The parameters 1 to 6 work fine, but in CSS mode,
document.execCommand("fontSize", false, "7") can't do anything useful.
 WebKit produces -webkit-xxx-large, which isn't interoperable, and
Gecko doesn't support CSS mode for fontSize at all.  The editing spec
says to output <font size=7> here even in CSS mode.

I'll point out that even if "font-size: xxx-large" is specced and
implemented, we won't be able to use it in editing code for a long
time to come, because it won't work in older UAs.  But at least we'll
be on the right track.

Received on Monday, 16 April 2012 10:44:22 UTC