Let's say the widget in question is a VBox containing a Label and two Buttons.
Furthermore, let's say the degree of rotation desired is 90°.
How does one go about rotating it? I do not think this is possible by default but I do think it is possible.
However, I have no idea how to get started. Do I write a custom widget? What do I subclass?
You can fake it like this:
label.set_angle(90)
button1.get_child().set_angle(90) # assuming it's not a stock button
button2.get_child().set_angle(90)
vbox.set_orientation(gtk.ORIENTATION_HORIZONTAL)