RE: textDecoration question

I’d suggest adding text clarifying this and of course, the schema should be fixed.

 

From: Glenn Adams [mailto:glenn@skynav.com] 
Sent: Sunday, May 12, 2013 5:50 PM
To: Michael A Dolan
Cc: public-tt
Subject: Re: textDecoration question

 

 

On Fri, Jun 22, 2012 at 6:00 PM, Michael A Dolan <mdolan@newtbt.com> wrote:

The prose for this attribute is not clear whether combinations of the pairs of attributes can be used.  The examples show only a single value at a time – e.g. either underline or lineThrough.

 

The syntax is constructed in an unusual manner if the intent was to only permit a single value.  The schema is currently an enumeration, forcing only a single value.

 

To understand the notation, you have to trace back to XSL-FO and thence to CSS 2. See [1].

 

[1] http://www.w3.org/TR/CSS2/about.html#value-defs

 

Specifically:

 

A double bar (||) separates two or more options: one or more of them must occur, in any order.

 

This would probably be more clear if someone hadn't removed the references to the XSL-FO definitions upon which the properties were based, though you can still trace it via Appendix J.2 Attribute Derivation [2].

 

[2] https://dvcs.w3.org/hg/ttml/raw-file/default/ttml10/spec/ttaf1-dfxp.html#attribute-vocab-derivation-table

 

In any case, the intent is not to permit a single value, e.g., "underline overline noLineThrough" is a valid value.

 

 

If the schema is correct, then one can never apply both underline and lineThrough concurrently – e.g. textDecoration=”underline lineThrough”.

 

Does the schema reflect the intent?  If so, then why the odd construction of the syntax in the prose?

 

Thanks,

 

                Mike

 

Michael A DOLAN

Television Broadcast Technology, Inc

PO Box 190, Del Mar, CA 92014 USA

+1-858-882-7497 <tel:%2B1-858-882-7497>  (m)