If this is not possible - what is a good way to calculate the longest line (in number of characters) so I can just use that and mutiply by an average width to get close?
                
    
                                    
            Hi,
 
 
have you looked at the StringLengthCalculator?
 
 
David
                
     
                                    
            SLC is in bytes, is it not?
 
 
I use boundingbox on the text attribute and extract its dimensions.
 
You need to (trial and error) adjust the value somewhat.
 
It is very dependant on the font type.
 
Look:
 

 
 
creates:
 

 
 
and zoomed in:
 

 
 
 
There is a tcl/TkCmd Font (wich has for instance Measure function) Wich is in pixels tough.