This tutorial on using GObject in Python only covers using a property of type gobject.TYPE_FLOAT.
I've adapted it to use an enumerated type:
import pygtk
pygtk.require('2.0')
import gobject
FUEL_NONE = 0
FUEL_SOME = 1
FUEL_FULL = 2
class Car(gobject.GObject):
__gproperties__ = {
'fuel' : (gobject.TYPE_ENUM, # type
'fuel of the car', # nick name
'amount of fuel that remains in the tank', # description
FUEL_SOME, # default value
gobject.PARAM_READWRITE) # flags
}
# <<rest of demo code>>
...but when I attempt to run it I get the following error:
/usr/lib/pymodules/python2.5/gtk-2.0/gobject/__init__.py:114: Warning: g_param_spec_enum: assertion `g_enum_get_value (enum_class, default_value) != NULL' failed
type_register(cls, namespace.get('__gtype_name__'))
Traceback (most recent call last):
File "gcar.py", line 9, in <module>
class Car(gobject.GObject):
File "/usr/lib/pymodules/python2.5/gtk-2.0/gobject/__init__.py", line 60, in __init__
cls._type_register(cls.__dict__)
File "/usr/lib/pymodules/python2.5/gtk-2.0/gobject/__init__.py", line 114, in _type_register
type_register(cls, namespace.get('__gtype_name__'))
TypeError: Error when calling the metaclass bases
could not create param spec for type GEnum (while registering property 'fuel' for GType '__main__+Car')
What am I missing?
It's not enough enough to tell __gproperties__ that it's an enumerated type; you need to register the enumeration with the GObject type system, and then use the GType value you get from that instead of gobject.TYPE_ENUM. At least, that's how it's done in C. I'm not sure what the proper way to do this is PyGTK is, but it might involve writing a .defs file and running pygobject-codegen-2.0 on it.
Of course, it's probably easier to just make the property of type gobject.TYPE_INT with a minimum and maximum value that matches the bounds of your enum, unless you really need the GObject system to understand the details of your enumeration.