creating custom shapes for visual storytelling

[dave boyle <twoten istop com>]

I want to use Dia to write a screenplay. I need to create a sheet of 
custom shapes with names like character, location, prop, costume, 
interaction, etc. Each shape will need custom dialog boxes that appear 
when Properties is clicked. These dialogs will allow the inputting of 
the necessary data that goes along with each story element-shape.

I've looked at the dialog box associated with the UML class shape which 
makes me think it might be possible, but is it? Can I create my own data 
objects and assign them to new shapes? Or is it just the UML class shape 
that has the ability to store extra information? With XML as the back 
end, what does it care about what I put in or where? As long as I 
conform to my DTD ...

I'm an experienced object oriented programmer with no experience in Dia. 
I'd like to know if what I want to do is even possible before making an 
investment on the learning curve. Thank you for your assistance!