I have extensive experience solving complex UI problems in Qt, for instance I developed the Qt porting of SWI-prolog console ( you can see my public repository [login to view URL] ), and provided an efficient rendering of Graphviz graphical interface ( see for instance [login to view URL]).
Recently, here on freelancer.com, I crafted a graph editor, extending the Graphviz interface cited above.
Hope you're interested in my collaboration.
Ing. Carlo Capelli