GRC Code Organization
These notes are an attempt to figure out how big of a project porting from pygtk to pyqt will be, by identifying which files have pygtk code and how much of it.
All of the pygtk code is in gnuradio/grc/gui, other than a few lines in gnuradio/grc/scripts
gi is GObject Introspection which seems to be a python GTK thing
grc uses GTK 3.0 and PangoCairo 1.0 which seems to be a way to render text using GTK
the entry point for GRC is in /gnuradio/grc/main.py which has no actual GTK code in it, it calls Application()