[maemo-developers] [pymaemo] How to add PyModule_AddObject to the override file?

[From: Anderson Lizardo]

On Thu, Jul 30, 2009 at 7:11 AM, Andrea Grandi<a.grandi at gmail.com> wrote:
> Hi,
>
>> All I've to do now is to write a real MAFW_TYPE_PLUGIN_DESCRIPTOR_PUBLIC.
>>
>> I'll keep you updated if I discover something new ;)
>
> I've decided to use the second way, writing a new Python type (like
> described here: http://docs.python.org/extending/newtypes.html )
> you can view the modified mafw.override here: http://pastebin.com/m2a280bb3
>
> and this is how it works from Python:
>
> [sbox-FREMANTLE_X86: ~] > python2.5
> Python 2.5.2 (r252:60911, Mar 16 2009, 16:36:21)
> [GCC 4.2.1] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import mafw
>>>> p = mafw.PluginDescriptorPublic()
>>>> p.name = "ciao"
>>>> print p.name
> ciao
>
> what do you think about? If it's ok, now we'll have to make
> list_plugins methid to be able to use this new type.

One suggestion: rename the "PluginDescriptorPublic" PyObject to
"PyMafwPluginDescriptorPublic", to avoid a possible name clash with
symbols from other headers. Same for the type struct:
PluginDescriptorPublic_Type -> PyMafwPluginDescriptorPublic_Type. I
think codegen generated types use the "Py<C_type>" and
"Py<C_type>_Type" patterns due to this.

Besides that, I can't really comment much on the code, I'll have to
trust that you tested the code and can modify the list_plugins
override to be able to actually use this type. The current override
will certainly not work because it relies on each item of the list
being a GObject, as can be shown by this line:

PyObject *item = pygobject_new((GObject *)g_list_nth_data(wlist, i));

Personally, I would probably opt for the "wrap around GType" method
described on that link too, because that way the overrides for the
methods that use that type could still use pygobject_new() to manage
instances. But that's just me, if you manage to make it work with
either methods (and have list_plugins() return valid instances of the
type), we would gladly accept your work :)

I can't really help you much on this, It's a whole new subject for me
and I'll probably not have time in the next weeks to play with
python-mafw code.

On a separate note, all all these "raw" (non GObject based) structs
that MAFW uses would make a PyBank based binding somewhat difficult
too, given that there it relies 100% on GObject introspection, I
think. With codegen, it is at least easier to write custom Python type
wrappers if you know some Python/C API.

Please keep us informed of your progress here in the list :) Keep up
the good work!

Regards,
-- 
Anderson Lizardo
OpenBossa Labs - INdT
Manaus - Brazil