Create a new, self-drawing widget in Perl code. This example shows how to subclass Glib::Object/Gtk2::Widget types, how to override class closures, how to define how much size you want to request for yourself, how to draw shapes and text with Gdk, how to handle mouse events, why you'd want to implement SET_PROPERTY for yourself, and how to emit signals. And the widget is actually functional, too. :-)