GtkWidgetget_toplevel

This function returns the topmost widget in the container hierarchy widget is a part of. If widget has no parent widgets, it will be returned as the topmost widget. No reference will be added to the returned widget; it should not be unreferenced.

Note the difference in behavior vs. gtk_widget_get_ancestor(); gtk_widget_get_ancestor (widget, GTK_TYPE_WINDOW) would return NULL if widget wasn’t inside a toplevel window, and if the window was inside a GtkWindow-derived widget which was in turn inside the toplevel GtkWindow. While the second case may seem unlikely, it actually happens when a GtkPlug is embedded inside a GtkSocket within the same application.

To reliably find the toplevel GtkWindow, use gtk_widget_get_toplevel() and call GTK_IS_WINDOW() on the result. For instance, to get the title of a widget’s toplevel window, one might use:

static const char *
get_widget_toplevel_title (GtkWidget *widget)
{
  GtkWidget *toplevel = gtk_widget_get_toplevel (widget);
  if (GTK_IS_WINDOW (toplevel))
    {
      return gtk_window_get_title (GTK_WINDOW (toplevel));
    }

  return NULL;
}