diff --git a/callback.c b/callback.c
index 604d4fb..868a628 100644
--- a/callback.c
+++ b/callback.c
@@ -180,20 +180,24 @@ void on_toggle_EXEC_EDIT (GtkWidget *btt_XOR_EXEC_EDIT, GtkWidget *btt_MODEL_RUN
   set_mode (0);
   } else {
   gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "preferences-system-symbolic");
-  gtk_button_set_icon_name (btt_XOR_EXEC_EDIT, "emblem-ok-symbolic"); //   Transport Steam Engine   !!
+  gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "emblem-ok-symbolic"); //   Transport Steam Engine   !!
   gtk_widget_set_sensitive (GTK_WIDGET (btt_MODEL_RUN_STOP), FALSE);
   set_mode (1);
   }
 }
 
+
+
+
+
 void on_open_STATE (GtkWidget *btt_open_STATE, gpointer data) {
   printf("on_open_STATE   status = %d\n", get_status ());
   printf("gtk_check_button_get_active >  after =  %d, %d, %d     from callback : on_open_STATE()\n",\
-          gtk_check_button_get_active (get_GtkButton ("state")), //  (GTK_CHECK_BUTTON (btt_open_STATE)),
-          gtk_check_button_get_active (get_GtkButton ("rules")), //  (GTK_CHECK_BUTTON (btt_open_RULES)),
-          gtk_check_button_get_active (get_GtkButton ("data analysis"))); //  (GTK_CHECK_BUTTON (btt_open_DATA)));
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("state"))), //  (GTK_CHECK_BUTTON (btt_open_STATE)),
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("rules"))), //  (GTK_CHECK_BUTTON (btt_open_RULES)),
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("data analysis")))); //  (GTK_CHECK_BUTTON (btt_open_DATA)));
 
-  if (! gtk_check_button_get_active (get_GtkButton ("state"))) window_main_child (main_window, STATE);
+  if (! gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("state")))) window_main_child (main_window, STATE);
 }// SWITCH_TO (STATE);}
 
 void on_open_RULES (GtkWidget *btt_open_RULES, gpointer data) {
@@ -202,10 +206,30 @@ void on_open_RULES (GtkWidget *btt_open_RULES, gpointer data) {
 }// SWITCH_TO (RULES);}
 
 void on_open_DATA  (GtkWidget *btt_open_DATA,  gpointer data) {
-  printf("on_open_DATA   status = %d\n", get_status ());
+  printf("on_open_DATA    status = %d\n", get_status ());
   window_main_child (main_window, DATA);
 }// SWITCH_TO (DATA);}
 
+
+
+
+
+void on_toggle_STATE_RULES_DATA (GtkToggleButton *source, gpointer user_data) {
+  //  https://docs.gtk.org/gtk4/class.ToggleButton.html  <  f..k !   bad code ++
+  // g_print ("Toggle button [%s] is active: %s\n", gtk_button_get_label (GTK_BUTTON (source)), gtk_toggle_button_get_active (source) ? "Yes" : "No");
+  int choice = 0;
+  switch (choice) {
+  case (STATE): get_GtkButton ("state"); break;  //  get_window_child_STATE ();
+  case (RULES): get_GtkButton ("rules"); break;  //  get_window_child_RULES (); break;
+  case (DATA):  get_GtkButton ("data analysis"); break;  //  get_window_child_DATA ();  break;
+  default :     get_GtkButton ("state"); break;  //  get_window_child_STATE ();
+  }
+}
+
+
+
+
+
 void on_SAVE_CURRENT_MODEL_BEFORE_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data) {
   gtk_widget_set_sensitive (GTK_WIDGET (data), TRUE);
   printf ("callback.c (line 201)  -  SAVE_CURRENT_MODEL_BEFORE_EDITING\n");
diff --git a/callback.h b/callback.h
index ac26745..79025dd 100644
--- a/callback.h
+++ b/callback.h
@@ -24,4 +24,4 @@ void on_open_DATA  (GtkWidget *btt_open_DATA,  gpointer data);
 void on_SAVE_CURRENT_MODEL_BEFORE_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data);
 void on_DISCARD_CURRENT_MODEL_AND_START_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data);
 void on_WRITE_CURRENT_MODEL (GtkWidget *btt_WRITE_CURRENT_MODEL, gpointer data);
-
+void on_toggle_STATE_RULES_DATA (GtkToggleButton *source, gpointer user_data);
diff --git a/contain.c b/contain.c
index 1e38679..32b4526 100644
--- a/contain.c
+++ b/contain.c
@@ -222,9 +222,9 @@ void window_header_bar (GtkWindow *window, char *title){
 //  gtk_check_button_set_active (GTK_CHECK_BUTTON (get_GtkButton ("state")), TRUE);
 
   printf("gtk_check_button_get_active >  after =  %d, %d, %d\n",\
-          gtk_check_button_get_active (get_GtkButton ("state")), //  (GTK_CHECK_BUTTON (btt_open_STATE)),
-          gtk_check_button_get_active (get_GtkButton ("rules")), //  (GTK_CHECK_BUTTON (btt_open_RULES)),
-          gtk_check_button_get_active (get_GtkButton ("data analysis"))); //  (GTK_CHECK_BUTTON (btt_open_DATA)));
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("state"))), //  (GTK_CHECK_BUTTON (btt_open_STATE)),
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("rules"))), //  (GTK_CHECK_BUTTON (btt_open_RULES)),
+          gtk_check_button_get_active (GTK_CHECK_BUTTON (get_GtkButton ("data analysis")))); //  (GTK_CHECK_BUTTON (btt_open_DATA)));
 
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_XOR_EXEC_EDIT));
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_MODEL_RUN_STOP)); //  <<  pas ici !  TODO
@@ -233,7 +233,8 @@ void window_header_bar (GtkWindow *window, char *title){
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_open_RULES));
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_open_DATA));
 
-//  icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
+
+  icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
 //                                                     https://iconduck.com/sets/carbon-icons   <   pas mal ...
 //  ma préférée : Transport Steam Engine Icon     mais : [ process icon ]  semble un bon choix...
 }