Re: Extra callback parameters

[Olexiy Avramchenko <olexiy irtech cn ua>]

Russell Shaw wrote:

> Hi,
> I have a callback that is passed one user data item (cdata):
>
> void colour_cb(GtkButton *button, gpointer data)
> {...
> }
> g_signal_connect(G_OBJECT(colbutton),"clicked",G_CALLBACK(colour_cb),cdata);
> Is it possible to modify g_object signals so that more than
> one data parameter can be passed like:

You can create your GObject class and define a signal (g_signal_new) 
with specific parameters list.

> void colour_cb(GtkButton *button, gpointer data1, gpointer data2)
> {...
> }
> g_signal_connect(G_OBJECT(colbutton),"clicked",G_CALLBACK(colour_cb),cdata1,cdata2);

No. It's impossible - "clicked" signal is defined in gtkbutton.c and it 
takes no extra parameters. Common way is to pass a pointer to structure 
(fast and takes no extra memory) or use g_object_set_data (slower, 
consumes memory).

   Olexiy