example-3.c

Developing with Gnome一书examples例子代码

/* This program displays a couple checkboxes and shows how to change
 * button labels, how to make widgets sensitive or unsensitive, how to
 * determine if a checkbox is active, how to provide access keys for
 * quick keyboard navigation, how to pass other widgets to callbacks
 * besides the one that receives the event, and how to manually get
 * gtk+ to update widgets without returning to the main event loop.
 */

#include <gtk/gtk.h>
#include <glade/glade.h>

void
quit_handler (gpointer user_data, GtkWidget *widget)
{
  /* If the user checked the OohTellMe button, we need to do some work... */
  GtkWidget * ooh_tell_me = (GtkWidget*) user_data;
  if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (ooh_tell_me)))
    {
      /* Change the checkbutton's label */
      gtk_button_set_label (GTK_BUTTON (ooh_tell_me),
                            "M_ock me");

      /* Since we don't return to the main event loop, we have to manually tell
       * gtk+ to process the gtk_button_set_label change (and any other changes
       * that require processing).
       */
      while (g_main_context_iteration (NULL, FALSE))
        ;

      /* Mock the user and give them some time to notice the change */
      printf ("Ha ha, you fell for it!  ");
      printf ("I will not tell you what that checkbutton does!\n");
      sleep (1);
    }

  gtk_main_quit ();
}

/* delete_handler merely calls quit_handler (it is needed because this
 * callback has a different number of parameters than quit_handler)
 */
gboolean
delete_handler (gpointer user_data, GdkEvent *event, GtkWidget *widget)
{
  quit_handler(user_data, widget);

  /* We have fully handled the signal */
  return TRUE;
}

void
sensitivity_toggled (gpointer user_data, GtkWidget *widget)
{
  gtk_widget_set_sensitive ((GtkWidget*) user_data, 
                            gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (widget)));
}

int
main (int argc, char *argv[])
{
  GladeXML *main_window;
  GtkWidget *widget, *ooh_tell_me;

  gtk_init (&argc, &argv);

  /* load the interface */
  main_window = glade_xml_new ("example-3.glade", NULL, NULL);

  /* connect the signals for the interface */
  ooh_tell_me = glade_xml_get_widget (main_window, "OohTellMe");
  widget      = glade_xml_get_widget (main_window, "SensitivityCheckButton");
  g_signal_connect_swapped (G_OBJECT (widget), "clicked",
                            G_CALLBACK (sensitivity_toggled),
                            G_OBJECT (ooh_tell_me));

  widget = glade_xml_get_widget (main_window, "OptionWindow");
  g_signal_connect_swapped (G_OBJECT (widget), "delete_event",
                            G_CALLBACK (delete_handler),
                            G_OBJECT (ooh_tell_me));

  widget = glade_xml_get_widget (main_window, "QuitButton");
  g_signal_connect_swapped (G_OBJECT (widget), "clicked",
                            G_CALLBACK (quit_handler),
                            G_OBJECT (ooh_tell_me));

  /* start the event loop */
  gtk_main ();

  return 0;
}