Re: [docbook] CALSpair format alternatives

[Michael Smith <smith@xml-doc.org>]

nico <nicolas.marsgui@libertysurf.fr> writes:

> Hello,
> 
> I would like to have more details about how <area> graphic coords calspair  
> units should be interpreted, and what are the valid formats.
> 
> In the TDG, only the format "x1,y1, x2,y2" is given (in area element  
> description), but I guess it is not the only one valid if you look at the  
> mediaobjectco, where the format is "x y".

That format in that example is not CALSPair. I think it is LineRange.

But I guess that mediaobjectco example is not so good, because it
doesn't specify any "units" attribute for Area. To be unambiguous,
it should specify bothe "coords" and "units".

Looking at TDG, I see that there are two attributes, "units" and
"otherunits", for specifying to an appliation how the value of the
"coords" attribute should be interpreted.

  The valid values of the "units" attribute are:

  CALSPair
      The format of the coordinates is “x1,y,x2,y2”

  LineColumn
      The format of the coordinates is “line column.

  LineRange
      The format of the coordinates is “startingline endingline.”

  LineColumnPair
      The format of the coordinates is “line1 col1 line2 col2”

  Other
      If specified, then the OtherUnits attribute is expected to
      identify the units in some implementation-specific way.

If you specify units='other', then you would need to also specify
a value for the "otherunits" attribute.

> So, are those formats all valid?
> - "x1,y1 x2,y2"

Yeah, that is CALSPair

> - "x y"

That is valid but could be either LineColumn or LineRange

> - "x1,y1" (if it is valid is it equivalent to "x1 y1"?)

Not valid as far as I know.

> Is there any other valid alternatives?

“line1 col1 line2 col2”

  --Mike

-- 
Michael Smith
http://sideshowbarker.net/

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