diff --git a/include/widget.h b/include/widget.h
index 1fc3772..a379674 100644
--- a/include/widget.h
+++ b/include/widget.h
@@ -28,6 +28,6 @@
 #pragma once
 #include <gtk-4.0/gtk/gtk.h>
 
-void on_windows_activation (GtkApplication *app);
-void widget_get_main_window (GtkWindow *main_window, GtkApplication *app);
-
+void on_app_activation (GtkApplication *app);
+void widget_design_main_window (GtkWindow *main_window, GtkApplication *app);
+gboolean on_window_close_request (GtkWindow *main_window, gpointer user_data);
diff --git a/src/main.c b/src/main.c
index 078977c..93aca3a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -74,7 +74,7 @@ int main (int argc, char **argv)
                        "| 👉️  windows creation requested");
 
 //  g_signal_connect (app, "startup",  G_CALLBACK (on_windows_startup), NULL);
-    g_signal_connect (app, "activate", G_CALLBACK (on_windows_activation), NULL);
+    g_signal_connect (app, "activate", G_CALLBACK (on_app_activation), NULL);
 
     status = g_application_run (G_APPLICATION (app), argc, argv);
     g_object_unref (app);
diff --git a/src/widget/main_window/design.c b/src/widget/main_window/design.c
index 7cfda4f..20bb98f 100644
--- a/src/widget/main_window/design.c
+++ b/src/widget/main_window/design.c
@@ -39,16 +39,16 @@
  * @param *main_window
  * @param *app
  */
-void widget_get_main_window (GtkWindow *main_window, GtkApplication *app)
+void widget_design_main_window (GtkWindow *main_window, GtkApplication *app)
 {
     fsm_add_log (INFO, TOPBAR, "widget/main_window/design",
                                "main window", "start of design");
 
-    GtkWidget *topbar = GTK_WIDGET (gtk_header_bar_new ());
+    /* GtkWidget *topbar = GTK_WIDGET (gtk_header_bar_new ()); */
 
-    char *title = "E coli   (with permission from David S. Goodsell, 2009)";
-    gtk_header_bar_set_title_widget (GTK_HEADER_BAR (topbar),
-                                     gtk_label_new (title));
+    /* char *title = "E coli   (with permission from David S. Goodsell, 2009)"; */
+    /* gtk_header_bar_set_title_widget (GTK_HEADER_BAR (topbar), */
+    /*                                  gtk_label_new (title)); */
 
     GtkWidget *e_coli = GTK_WIDGET (gtk_picture_new_for_filename
                           ("./docs/showcase/E coli (Goodsell).png"));
@@ -60,4 +60,3 @@ void widget_get_main_window (GtkWindow *main_window, GtkApplication *app)
     fsm_add_log (INFO, TOPBAR, "widget/main_window/design",
                                "main window", "ready for presentation");
 }
-
diff --git a/src/widget/manager.c b/src/widget/manager.c
index 9f93bcb..95ae579 100644
--- a/src/widget/manager.c
+++ b/src/widget/manager.c
@@ -35,20 +35,18 @@
 
 #include <stdio.h>
 
-static GtkWindow *main_window;
+static GtkWindow *window;
 
 
 /**
  * @brief 1) creates a new main window  2) presents this window
  *
- * NB > on_windows_activation() is in: widget/manager  NOT in: src/signal
+ * NB > on_app_activation() is in: widget/manager  NOT in: src/signal
  *
  * @since 2024-06
  *
  * @callgraph
  * @see widget_design_main_window()
- * @see widget_design_dialog_window()
- * @see widget_design_text_window()
  * @see util_trigger_test()
  * @see fsm_add_log()
  *
@@ -57,9 +55,9 @@ static GtkWindow *main_window;
  *
  * @param *app
  */
-void on_windows_activation (GtkApplication *app)
+void on_app_activation (GtkApplication *app)
 {
-    fsm_add_log (INFO, WIDGETS, "widget/manager", "windows activation()", "has began");
+    fsm_add_log (INFO, WIDGETS, "widget/manager", "app activation()", "has began");
 
     //  on_windows_activation() is in: widget/manager  NOT in:  src/signal
     //  g_application_activate (G_APPLICATION (app));   <   how ?   >   in main is
@@ -76,12 +74,14 @@ void on_windows_activation (GtkApplication *app)
     //gtk_widget_destroy(widget);
 
 
-    main_window   = GTK_WINDOW (gtk_application_window_new (app));
+    window   = GTK_WINDOW (gtk_application_window_new (app));
 
-    int window_int_id = gtk_application_window_get_id (GTK_APPLICATION_WINDOW (main_window));
+    int window_int_id = gtk_application_window_get_id (GTK_APPLICATION_WINDOW (window));
     char window_char_id[40];
     sprintf(window_char_id, "%d", window_int_id);
 
+    g_signal_connect(window, "close-request", G_CALLBACK (on_window_close_request), (void *)(long long)window_int_id);
+
     //printf ("gtk_application_window_id = %s = %d\n", window_char_id, window_int_id);
 
     fsm_add_log (INFO, WIDGETS, "widget/manager", "gtk_application_window_get_id",
@@ -90,9 +90,9 @@ void on_windows_activation (GtkApplication *app)
     //printf ("gtk_application_window_get_id (main_window) = %d\n",
             //gtk_application_window_get_id (GTK_APPLICATION_WINDOW (main_window)));
 
-    widget_get_main_window   (main_window, app);
+    widget_design_main_window   (window, app);
 
-    gtk_window_present (GTK_WINDOW (main_window));
+    gtk_window_present (GTK_WINDOW (window));
 
     // g_object_unref (main_window); TODO get the closing signal of the main window
 
@@ -117,7 +117,21 @@ void on_windows_activation (GtkApplication *app)
     g_action_map_add_action (G_ACTION_MAP (app), G_ACTION (act_b));
     g_signal_connect (act_b, "activate", G_CALLBACK (action_b), app2);*/
 
-    fsm_add_log (INFO, WIDGETS, "widget/manager", "windows activation()",
+    fsm_add_log (INFO, WIDGETS, "widget/manager", "app activation()",
                        "has ended 🧐️ | 👉️ a new session starts");
 }
 
+gboolean on_window_close_request (GtkWindow *window, gpointer user_data)
+{
+
+    fsm_add_log (INFO, WIDGETS, "widget/manager", "window close request()",
+                       "freeing all ressources !");
+
+    // free the only child
+    gtk_window_set_child (window, NULL); // deleting the child from window
+
+    // drop window's reference
+    gtk_window_destroy (window);
+
+    return false; // the default handler takes care of g_object_unref for window
+}