Re: How can I use g_signal_connect() to pass a gponiter parameter

[Jean Bréfort <jean brefort normalesup org>]

Le dimanche 01 février 2009 à 10:22 -0800, frantishek a écrit :
> My code does it just by the book:
> 
> void setPermission(GtkWidget *window, gpointer p)
> {
> 	g_print("%s\n", (gchar*) p);
> }
> 
> radio1 = gtk_radio_button_new_with_label (NULL, "First");
> radio2 = gtk_radio_button_new_with_label_from_widget (GTK_RADIO_BUTTON
> (radio1), "Second");
> radio3 = gtk_radio_button_new_with_label_from_widget (GTK_RADIO_BUTTON
> (radio1), "Third");
> g_signal_connect_swapped (G_OBJECT (radio1), "clicked", G_CALLBACK
> (setPermission), (gpointer) "Clicked 0");    
> g_signal_connect_swapped (G_OBJECT (radio2), "clicked", G_CALLBACK
> (setPermission), (gpointer) "Clicked 1");    
> g_signal_connect_swapped (G_OBJECT (radio3), "clicked", G_CALLBACK
> (setPermission), (gpointer) "Clicked 2");    
> 
> Yet, when I select any of these radio buttons, it prints out some garbage
> (the same for each button).
> 
> Any idea why?

You are using g_singal_connect_swapped, so your gpointer becomes the
first argument of the callback which should be 

void setPermission(gpointer p)
{
	g_print("%s\n", (gchar*) p);
}


> learning_gtk wrote:
> > 
> > I hope to use  g_signal_connect() to pass a gchar* parameter like this:
> > 
> > gchar* radio1= "Radio1"; //it is global variable
> > gchar* radio2= "Radio2";
> > gchar* radio3= "Radio3";
> > 
> > void item_radio_print1(gpointer* data)
> > {
> >         g_print("This is the radio %s\n", (gchar *)data);
> > }
> > 
> > g_signal_connect(G_OBJECT(item_radio1), "activate",
> >                      GTK_SIGNAL_FUNC(item_radio_print1),
> > (gpointer*)radio1);
> > g_signal_connect(G_OBJECT(item_radio2), "activate",
> >                      GTK_SIGNAL_FUNC(item_radio_print1),
> > (gpointer*)radio2);
> > g_signal_connect(G_OBJECT(item_radio3), "activate",
> >                      GTK_SIGNAL_FUNC(item_radio_print1),
> > (gpointer*)radio3);
> > 
> > But, those strings can not be printed.
> > 
> > Please help me. Thanks!
> > 
>