Using Just the Font Metrics Stuff From FOP

[Eliot Kimber]

Here's my problem: during XSLT processing to generate FO instances I 
need to be able to make a reasonable guess as to the rendered length of 
a given string so that I can do some simple automatic copy fitting, such 
as setting the list label width to fit the longest item in a definition 
list. I know this can't be exact because of variables like kerning and 
justification, but in the normal case of unjustified, relatively short 
strings I should be able to get within an Em width of the correct length.

I think I should be able to do this using the font metric support in the 
current development version of FOP but I'm having a hard time figuring 
out exactly what bits are involved. I think where I'm stuck is on what 
code actually takes a font and generates a metrics file from it. I've 
traced down to where the XML font metrics files are loaded but it 
appears that the font metrics files just exist.

Also, I need to be able to process OpenType fonts and it's not clear 
from the code and the archives whether that's currently implemented, 
although I did see a couple messages discussing it.

What I want to implement is an XSLT extension function something like this:

public static int renderedStringLength(String str,
                                       String fontFamilyName,
                                       int fontSize) {
        Font font = magicFopFontHelper.getFont(fontFamilyName,
                                               fontSize);
        return font.getWordWidth(str);
}
Obviously, it's the "magicFopFontHelper" class that I'm not sure how to 
go about constructing.

Can someone point me in the right direction?

Thanks,

Eliot
--
W. Eliot Kimber
Professional Services
Innodata Isogen
9030 Research Blvd, #410
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(512) 372-8122
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