QtRuby and Wrapping custom Qt derived C++ classes

I’ve been working with QtRuby a bit recently and I’ve come to the point
where I want to investigate wrapping a c++ class [a custom
QGraphicsItem] so that I can instantiate it on the ruby side and use it
with a Qt::GraphicsScene.

Does anyone have an example of this? It would be fine if it was just a
QWidget or some other QT derived class…

Do I need to use smoke? Does everyone create a custom ruby interface
[with the library init etc] or can we use something like swig to do that
for us or does smoke have a way to produce a language specific binding?

Thanks,
Alex