Re: reply to CSS WG comments on SVG 1.2

On Monday, February 28, 2005, 9:46:40 PM, Dean wrote:



DJ> On 1 Mar 2005, at 11:56, Boris Zbarsky wrote:

>> Dean Jackson wrote:
>>>  > b) The 'text-align' property in SVG 1.2 is different than in CSS.
>>> This
>>>  > makes it impossible for the property to be used in a 
>>> mixed-namespace
>>>  > environment. We request that the property be used unchanged.
>>> It is being used unchanged. The 'text-align' property is taken from
>>> XSL because it is stable (REC from 2001), internationalized and does
>>> not have problematic values such as 'left' and 'right'.
>>> For details: http://www.w3.org/TR/xsl/slice7.html#text-align
>>
>> I'm sorry, but I must be missing something.  The allowed values for 
>> this property in the cited specification are a superset of the CSS 2.1
>> values (and in fact are a superset of the proposed CSS 3 Text values),
>> and are NOT the same as the proposed SVG 1.2 values (which are a 
>> proper subset of the CSS 3 Text values and neither a subset nor a 
>> superset of the CSS2.1 values).  Could you please point out what, 
>> exactly, I'm missing?

DJ> I don't think you are missing anything - I think you're right.

DJ> XSL's text-align does allow 'left' and 'right'. They are
DJ> defined to be equivalent to 'start' and 'end' (producing the
DJ> situation where 'left' sometimes means right, and visa versa)

Which is

a) confusing
b) not compatible with CSS 2.1, where left always means left (at least,
for horizontal writing) and never right.

Summary: in XSL, left means start so it can mean right (in an RTL
context) or top (in a TTB context) or bottom (in a BTT context). While
in CSS2.1, left means left. And in CSS3, as far as I can tell, left can
mean top (in a TTB context) or bottom (in a BTT context) but never
right.

Observing that text-anchor is interoperably implemented on desktop and
mobile since SVG 1.0, the values of start, middle and end have not
caused any confusion and always mean start, middle, and end; we decided
for SVG 1.2 that text-align would have start, center, and end (and
justify, which can be done on flowing text but not on anchored text).

DJ> So, in summary, I think the SVG 1.2 definition is wrong (as
DJ> is the reply from the SVG WG). I'm not sure where we got the
DJ> idea that 'left' and 'right' had been removed.

From the minutes of the meetings, I suspect.





-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 W3C Graphics Activity Lead

Received on Tuesday, 1 March 2005 15:31:45 UTC