[GSoC 2014] Code pointers for text properties in Draw

Hi all,
I'm working on adding text background color to Draw text frames but I
suspect I'm having troubles finding my way through the basics of the whole
application's architecture.
Browsing through code in sd/,  I haven't found anything that seemed to deal
specifically with text properties.
I suppose most of the responsibility for text features is in some external
module (editeng, by any chance?), but I don't understand where it is that
Draw-specific code makes use of these features.

Could anyone point to any documentation/code I could look at or could
anyone help me get clarity on this point?

Cheers,
Matteo