Re: Newbie Question: g_signal_*

[Owen Taylor <otaylor redhat com>]

John Darrington <jmd computer org> writes:

> Clearly I'm missing something with the gobject signalling mechanism.
>
> In the documentation, *all* the gtk_signal_* functions have a note 
> saying: 
>       gtk_signal_* is deprecated and should not be used in
>       newly-written code.
>
> which is not very useful as it doesn't say what *should* be used
> instead.   I'm guessing that I should use g_signal_*
>
> However when I look at g_signal_connect , the callback function has a 
> signature of
>
>         void GCallback (void);
>
> which is not much use if I want to actually do something when I catch
> the signal.  How do I get the data associated with the signal? And how
> do I determine which object emitted the signal?

A dummy typedef has to be used because there is no one signature
for all signals -- different signals have different arguments
and return values.

Use the appropriate callback signature from the docs for the
signal you are connecting to, and cast it to a GCallback with the 
G_CALLBACK() macro.

[ gtk_signal_connect worked the same way, BTW ]

Regards,
                                        Owen