Re: [office] proposal; Amend fo:letter-spacing

[robert_weir@us.ibm.com]

Thomas Zander <zander@kde.org> wrote on 06/05/2008
11:56:45 AM:

> Hello TC,
> 
> In ODF the letter spacing attribute specifies the amount of space
between 
> letters. This is the way that XSL does things and this is fine for
things 
> like webpages.
> Unfortunately for DTP applications this is not really what is expected.
The 
> spacing between characters in DTP is not a static value, it is a percentage
> value.  Basically when you have an 'm' the spacing adjustment
is wider than 
> when you have an 'i'.
> In KOffice we intend to use the percentage based letter spacing 
> adjustment and 
> we were surprised reading the spec (and trying out OOo) that this
is not 
> possible.  Would it be possible to adjust the spec to also allow
percentage 
> based values?
> 
> Which would add the <ref name="percent"/> and we end
up with the following;
> 
> <define name="style-text-properties-attlist" combine="interleave">
>     <optional>
>         <attribute name="fo:letter-spacing">
>             <choice>
>                 <ref name="length"/>
>                 <value>normal</value>
>                 <ref name="percent"/>
>             </choice>
>         </attribute>
>     </optional>
> </define>
> 

I wonder if you already have the ability to do this
with length?  Specifically, if I set length to be 0.5em, does this
really mean that exactly 0.5em is added after every character?  Or
does it mean that a nominal 0.5em is added, but the actual space applied
is kerned according to typeface-specific ratios?

In other words, don't we have a model where we specify
nominal spacing in the markup and then kerning occurs as an implementation-dependent
algorithm?

-Rob