Re: Defining custom GObject signals with itself as an argument

[Timo <timovwb gmail com>]

Op 21-03-15 om 06:05 schreef Michael Gratton:
> On Sat, 21 Mar, 2015 at 3:43 PM, Michael Gratton <mike vee net> wrote:
> > I am trying to create a GObject subclass in Python3 that has instances
> > of the class itself as one of the signal's arguments.
>
>
> Oh! I just realised that the source object will be passed through as 
> the frist arg to the signal handler, even if you don't add it as an 
> arg in the signal definition.
>
> I'd still like to know if there's a workaround, since I'd also like to 
> be able to do the following:
>
> > class Primary(GObject):
> >     __gsignals__ = { 'activate': (Object.SIGNAL_RUN_FIRST, None, 
> (Secondary,)) }
> >
> > class Secondary(Object): pass
>
> Without, counter intuitively, having to define Secondary first.
You could use the GObject.signal_new helper method and define the signal 
outside of your class.

Example, untested:

class Primary(GObject): pass
class Secondary(GObject): pass
GObject.signal_new("activate", Primary, GObject.SIGNAL_RUN_FIRST, None, 
(Secondary,))

Downside is that this code is outside of the class and somewhere at the 
bottom of the file, easily overlooked.

Timo

> Thanks,
> //Mike