How to check if a radiobutton is selected in GTK - c

Question

I am trying to create a GUI in GTK using C. I want to have radio buttons but I don't know how to determine which one is selected.
#include <glib.h>
#include <gtk/gtk.h>
static gboolean close_application( GtkWidget *widget,
GdkEvent *event,
gpointer data )
{
gtk_main_quit ();
return FALSE;
}
static void btn_selected()
{
//pop-up message; left empty for now
}
int main( int argc,
char *argv[] )
{
GtkWidget *window = NULL;
GtkWidget *box1;
GtkWidget *box2;
GtkWidget *button;
GtkWidget *separator;
GSList *group;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
g_signal_connect (window, "delete-event",
G_CALLBACK (close_application),
NULL);
gtk_window_set_title (GTK_WINDOW (window), "radio buttons");
gtk_container_set_border_width (GTK_CONTAINER (window), 0);
box1 = gtk_vbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (window), box1);
gtk_widget_show (box1);
box2 = gtk_vbox_new (FALSE, 10);
gtk_container_set_border_width (GTK_CONTAINER (box2), 10);
gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0);
gtk_widget_show (box2);
button = gtk_radio_button_new_with_label (NULL, "button1");
gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0);
gtk_widget_show (button);
group = gtk_radio_button_get_group (GTK_RADIO_BUTTON (button));
button = gtk_radio_button_new_with_label (group, "button2");
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0);
gtk_widget_show (button);
button = gtk_radio_button_new_with_label_from_widget (GTK_RADIO_BUTTON (button),
"button3");
gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0);
gtk_widget_show (button);
separator = gtk_hseparator_new ();
gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 0);
gtk_widget_show (separator);
box2 = gtk_vbox_new (FALSE, 10);
gtk_container_set_border_width (GTK_CONTAINER (box2), 10);
gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, TRUE, 0);
gtk_widget_show (box2);
button = gtk_button_new_with_label ("close");
g_signal_connect_swapped (button, "clicked",
G_CALLBACK (close_application),
window);
gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0);
gtk_widget_set_can_default (button, TRUE);
gtk_widget_grab_default (button);
gtk_widget_show (button);
//This button will call the btn_selected method when clicked
button = gtk_button_new_with_label("selected");
g_signal_connect(button,"clicked",G_CALLBACK (btn_selected),NULL);
gtk_box_pack_start(GTK_BOX(box2),button,TRUE,TRUE,0);
gtk_widget_show(button);
gtk_widget_show (window);
gtk_main ();
return 0;
}
The GUI comes up without any errors, I just don't know to check which radio button was selected so I can perform an action. Since all the buttons are named button I don't know how to check for a specific one.I got this code from a gtk tutorial online.
Any ideas would be greatly appreciated.

Answer 1

GtkRadioButton is descended from GtkToggleButton so you can connect to the 'toggled' signal or use the 'active' property to the the state of the button.