Save button becomes unsensitive when nothing is chosen

source/libublsettingsui-gtk3.c

@@ -76,6 +76,18 @@ void on_save_window_parameter_switched(GtkCellRendererToggle *self, gchar *path,
         gtk_tree_model_get(GTK_TREE_MODEL(window->list),&iter,0,&is_active,-1);
         gtk_list_store_set(window->list,&iter,0,!is_active,-1);
     }
+    int once_active=0;
+    int valid = gtk_tree_model_get_iter_first(GTK_TREE_MODEL(window->list),&iter);
+    for (;valid;valid=gtk_tree_model_iter_next(GTK_TREE_MODEL(window->list),&iter)){
+        int is_active;
+        gtk_tree_model_get(GTK_TREE_MODEL(window->list),&iter,0,&is_active,-1);
+        if (is_active){
+            once_active=1;
+            break;
+        }
+    }
+    if (!once_active) gtk_widget_set_sensitive(window->SaveButton,0);
+    else gtk_widget_set_sensitive(window->SaveButton,1);
 
 }