PyGobject Callback Signature

[Anonimista]

(I wasn't sure if I should post this here or in the 'Absolute Beginners' Section', but it's a development question, so I'll post it here.)

I found several tutorials, like The Python GTK+ 3 Tutorial (http://python-gtk-3-tutorial.readthedocs.org/en/latest/index.html), which is pretty nice for a novice.

I am struggling to find PyGObject documentation, I am not clear on the callback functions signature. In the above tutorial the connect() call looks like this


self.button.connect("clicked", self.on_button_clicked)

and the callback looks like this:


def on_button_clicked(self, widget):
print("Hello World")

the widget parameter being the button which connect() was called (am I right?). Elsewhere I have seen callbacks like this:


def on_button_clicked(self, widget, data=None):
print("Hello World")

On gnome.org (https://developer.gnome.org/gobject/stable/gobject-Closures.html#GCallback) I fount this:

' The required signature of a callback function is determined by the context in which is used (e.g. the signal to which it is connected).'

I would like to know how could I determine the appropriate callback signature for any given signal. Thanks in advance.

[Anonimista]

To answer the question, I should have read the documentation. For example GtkButton clicked signal (https://developer.gnome.org/gtk3/3.2/GtkButton.html#GtkButton-clicked).