diff --git a/src/ui/sand_box.c b/src/ui/sand_box.c
index 7cc7ab3..2be5ad3 100644
--- a/src/ui/sand_box.c
+++ b/src/ui/sand_box.c
@@ -32,7 +32,8 @@ static void on_destroy (GtkWidget *widget, gpointer data) {if (data) g_print (da
 void on_activate_window_creation (GtkApplication *app, gpointer data)
 {
     GtkWidget *that_window = gtk_application_window_new (gtk_application_new ("org.gtk.test", 0));
-    g_signal_connect (G_OBJECT (that_window), "destroy", G_CALLBACK(on_destroy), "exit(0) closes window\n");
+    g_signal_connect (G_OBJECT (that_window), "destroy", G_CALLBACK(on_destroy),
+                      "sand_box.c / on_activate_window_creation()  >  exit(0) closes window\n");
     gtk_window_set_title (GTK_WINDOW(that_window), "Ignition !");
     gtk_window_set_default_size (GTK_WINDOW(that_window), 180, 140);
     GtkWidget *my_scrolling_thing = gtk_scrolled_window_new ();
@@ -46,9 +47,8 @@ void on_activate_window_creation (GtkApplication *app, gpointer data)
 static void on_setup_cb (GtkSignalListItemFactory *self, GtkListItem *my_list_item, gpointer user_data)
 {
     GtkWidget *my_label = gtk_label_new (NULL);
-    gtk_list_item_set_child (my_list_item, my_label);
-    /* Because gtk_list_item_set_child sunk the floating reference of my_label,
-     * releasing (unref) isn't necessary for my_label. */
+    gtk_list_item_set_child (my_list_item, my_label);  // Because gtk_list_item_set_child sunk the floating reference of my_label,
+                                                       // releasing (unref) isn't necessary for my_label.
 }
 
 static void on_bind_cb (GtkSignalListItemFactory *self, GtkListItem *my_list_item, gpointer user_data)
@@ -68,14 +68,16 @@ static void on_selection_change (GtkStringList *my_selection_model,  guint posit
         g_list_model_get_n_items (G_LIST_MODEL (my_selection_model)),
         g_list_model_get_item_type(G_LIST_MODEL (my_selection_model)),
         position,
-        gtk_string_object_get_string (g_list_model_get_item (my_selection_model, position)),
+        gtk_string_object_get_string (g_list_model_get_item (G_LIST_MODEL (my_selection_model), position)),
         n_items);
 }
 
 //-------------------------------------------------------------------------------------------------------------------------------------------
 
-void on_activating_this_expander (GtkExpander *my_expander, gpointer my_data) {printf("on_activating exp.  >   %s\n", gtk_string_object_get_string (GTK_STRING_OBJECT(my_expander)));}
-void gtk_expander_set_child      (GtkExpander* expander, GtkWidget* child) {printf("gtk_expander_set_child ()   %s\n", gtk_string_object_get_string (GTK_STRING_OBJECT(child)));}
+void on_activating_this_expander (GtkExpander *my_expander, gpointer my_data) {
+    printf("on_activating exp.  >   %s\n", gtk_string_object_get_string (GTK_STRING_OBJECT(my_expander)));}
+void gtk_expander_set_child      (GtkExpander* expander, GtkWidget* child) {
+    printf("gtk_expander_set_child ()   %s\n", gtk_string_object_get_string (GTK_STRING_OBJECT(child)));}
 
 GListModel *my_item_create_func (gpointer item, gpointer user_data)
 {
@@ -108,18 +110,16 @@ static void and_now_let_s_climb_that_tree (GtkWidget *in_that_box)
     if (1) { g_signal_connect (my_selection_model, "selection-changed", G_CALLBACK (on_selection_change), NULL);}
 
 
-//  GListModel *(* GtkTreeListModelCreateModelFunc) (GObject* item, gpointer user_data)  //  remplacerait gtk_string_list_new() ?
 //  https://docs.gtk.org/gtk4/callback.TreeListModelCreateModelFunc.html
 //  https://docs.gtk.org/gtk4/method.TreeListRow.set_expanded.html
 
-    GtkTreeListModel *my_tree_list_model = gtk_tree_list_model_new (G_LIST_MODEL (my_string_list), 1, 0, my_item_create_func, NULL, NULL); // my_string_list   my_selection_model
+    GtkTreeListModel *my_tree_list_model = gtk_tree_list_model_new (G_LIST_MODEL (my_string_list), 1, 0, my_item_create_func, NULL, NULL);
     int rank = 1; printf("in : GListModel *item_create_func (gpointer item,...)   (line 80)     (item n°%d is %s)\n",
                       rank, gtk_string_list_get_string (my_string_list, rank));
 
     GtkWidget *my_list_view = gtk_list_view_new (GTK_SELECTION_MODEL (my_selection_model), my_list_item_factory);
-//    GtkWidget *my_tree_view = gtk_tree_view_new ();
-    gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (in_that_box), my_list_view); // use  my_tree_view  instead of  my_list_view
-//    gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (in_that_box), gtk_tree_view_new ()); // use  my_tree_view  instead of  my_list_view
+//  GtkWidget *my_tree_view = gtk_tree_view_new ();   next line : use  my_tree_view  instead of  my_list_view ?
+    gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (in_that_box), my_list_view);
 }