Re: Compound datatypes: <length-range>

At 12:21 2001 09 28 -0400, Peter B. West wrote:
>In 5.11 Property Datatypes, <length> and <percentage> are defined separately, 
>and <length-range> is specified as:
>'A compound datatype, with components: minimum, optimum, maximum. 
>Each component is a <length>.'
>
>7.21.4 "leader-length" has:
>
>'Value: <length-range> | <percentage> | inherit
>Initial: leader-length.minimum=0pt, .optimum=12.0pt, .maximum=100%
>Applies to: fo:leader
>Inherited: yes
>Percentages: refer to width of content-rectangle of parent area
>Media: visual
>
>Values have the following meanings:
>
><length-range>
>...'
>
>There is no discussion of the meaning of <percentage> corresponding to 
>the discussion of the meaning of <length-range>.

We do already say:

  Percentages: refer to width of content-rectangle of parent area

so I'm not sure what else needs to be discussed.  (We are planning to
reword this somewhat to be in terms of the inline-progression-dimension
instead of width.)

>Further on, the following example is given:
>
>leader-length.minimum="0pt"
>leader-length.optimum="12pt"
>leader-length.maximum="100%"
>
>In other words, the value of the leader-length property is not a 
><length-range> or a <percentage>, it is a <length-range> whose components 
>are not simply <length>s, but <length>|<percentage>. 'inherit' is presumably 
>excluded by the constraint that compound datatypes may only be inherited as a 
>compound.  If my understanding is correct, the actual specification of the 
>allowable value of leader-length is <length-percentage-range>|inherit, where 
>each component of <length-percentage-range> is <length>|<percentage>.

Our data-typing is based on the refined values, not the specified values.

>I assume from 7.21.4 that it is not intended to allow entries like
>leader-length="20%".

That is allowed; it means:

leader-length.minimum="20%"
leader-length.optimum="20%"
leader-length.maximum="20%"

and then the 20% gets refined into a value which is 20% of the 
inline-progression-dimension of the parent's content rectangle
(which might be, say, the current column width).

paul

Received on Thursday, 4 October 2001 10:19:02 UTC