added checking function for showing RMB menu

source/ubl-settings-usergroups.c

@@ -2618,6 +2618,15 @@ void on_config_update(GtkWidget *self, main_window *widgets){
 	}
 }
 
+ int *yon_element_chosen(GtkWidget *target){
+	GtkTreeModel *model;
+	GtkTreeIter iter;
+	model = gtk_tree_view_get_model(GTK_TREE_VIEW(target));
+	if (gtk_tree_selection_get_selected(gtk_tree_view_get_selection(GTK_TREE_VIEW(target)),&model,&iter)){
+		return (int*)0x1;
+	}
+	return (int*)0x0;
+ }
 
 /**config_init() 
  * [EN] 
@@ -2734,6 +2743,8 @@ void on_notebook_page_changed(GtkWidget *self, GtkWidget *page, int num, main_wi
 	}
 }
 
+typedef int (*RmbCheck)(void*);
+
 /**yon_main_window_complete(main_window *widgets) 
  * [EN] 
  *  
@@ -2788,8 +2799,8 @@ main_window *yon_main_window_complete(main_window *widgets){
     g_signal_connect(G_OBJECT(widgets->LoadGlobalMenuItem),"activate",G_CALLBACK(on_config_global_load),widgets);
     g_signal_connect(G_OBJECT(widgets->LoadLocalMenuItem),"activate",G_CALLBACK(on_config_local_load),widgets);
     g_signal_connect(G_OBJECT(widgets->LoadCustomMenuItem),"activate",G_CALLBACK(on_config_custom_load),widgets);
-	yon_rmb_menu_setup(widgets->UsersTree,EDIT_LABEL,edit_icon_name,G_CALLBACK(on_main_edit),widgets,REMOVE_LABEL,delete_icon_name,G_CALLBACK(on_main_delete),widgets,NULL);
+	yon_rmb_menu_setup(widgets->UsersTree,(RmbCheck)yon_element_chosen,widgets->UsersTree,EDIT_LABEL,edit_icon_name,G_CALLBACK(on_main_edit),widgets, REMOVE_LABEL,delete_icon_name,G_CALLBACK(on_main_delete),widgets,NULL);
-	yon_rmb_menu_setup(widgets->GroupsTree,EDIT_LABEL,edit_icon_name,G_CALLBACK(on_main_edit),widgets,REMOVE_LABEL,delete_icon_name,G_CALLBACK(on_main_delete),widgets,NULL);
+	yon_rmb_menu_setup(widgets->GroupsTree,(RmbCheck)yon_element_chosen,widgets->GroupsTree,EDIT_LABEL,edit_icon_name,G_CALLBACK(on_main_edit),widgets,REMOVE_LABEL,delete_icon_name,G_CALLBACK(on_main_delete),widgets,NULL);
 
 	yon_gtk_tree_view_minimal_fixed_size_set_full(GTK_TREE_VIEW(widgets->UsersTree));
 	yon_gtk_tree_view_minimal_fixed_size_set_full(GTK_TREE_VIEW(widgets->GroupsTree));