Re: [gtk-list] Re: Signals and callbacks

[Karl Mitchell <k l mitchell lancaster ac uk>]

Rodrigo Moya wrote:

> If what you mean is how to pass this data to the callback, you should
> replace the above function line with:
>
>     gtk_signal_connect (GTK_OBJECT (event_box_right), "button_press_event",
>         GTK_SIGNAL_FUNC (magnify_image),  (gpointer) &_imageData);
>
> replacing _imageData with the name of the variable you want to pass.
> gpointer is just a void *.

To elaborate further, I tried the following and it gave an output of 683292. I
felt sure this would work. What have I missed? Please excuse the scrappy
cutting...
-----

void magnify_image( GtkWidget *widget, GdkEventButton *event, gint *data ){
  ...
  g_print("%d", *data)
  ...
}

int main(int argc, char **argv){
 gint *mf;
...
 mf =1;
 gtk_signal_connect (GTK_OBJECT (event_box_right), "button_press_event",
        GTK_SIGNAL_FUNC (magnify_image),  (gpointer) &mf);
...
}

-----

Cheers,

-Karl

--
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-Karl Mitchell=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
| Planetary Science Research Group |     Secretary, ISPRS WG IV/5      |
|   Environmental Sciences Dept.   |    "Extraterrestrial Mapping"     |
|  I.E.N.S., Lancaster University  | http://www.ge.ucl.ac.uk/isprs-etm |
| Lancaster LA1 4YQ, England, U.K. | tel/fax: +44(0)1524 593975/593985 |
 =-=-=-=-=-=-=-=-=-=-=k.l.mitchell@lancaster.ac.uk=-=-=-=-=-=-=-=-=-=-=