learning GTK4 tree (bottom-up)

display.h

@@ -9,6 +9,7 @@
 
 GtkWidget *get_text_view();
 GtkFrame *get_frame_with_label();
+GtkWidget *get_run_rules_page_new();
 
 GtkWidget *get_image_ALL_SPACE();
 GtkWidget *get_image_GLUTAMATE();

hot.c

@@ -15,11 +15,12 @@
 
 static void on_experimental_expander_toggled(GtkExpander *expander, gpointer user_data){
   gtk_expander_set_expanded (expander, gtk_expander_get_expanded (expander));
-  printf(">>>>>>>  %s  <<<<<<<\n", gtk_expander_get_label (user_data));
+  printf(">  %s\n", gtk_expander_get_label (user_data));
 }
 
 GtkBox *get_experimental_box_new(){
   GtkBox *experimental_box = GTK_BOX(gtk_box_new (GTK_ORIENTATION_VERTICAL, 0));
+  gtk_widget_set_size_request (GTK_WIDGET (experimental_box), 0, 400);
   gtk_box_append (experimental_box, GTK_WIDGET(gtk_separator_new (GTK_ORIENTATION_HORIZONTAL)));
   gtk_box_append (experimental_box, GTK_WIDGET(gtk_label_new ("\n\n")));
 
@@ -32,11 +33,10 @@ GtkBox *get_experimental_box_new(){
   GtkExpander *it_s_me = GTK_EXPANDER (gtk_expander_new ("it's me !"));
   gtk_expander_set_expanded (GTK_EXPANDER (it_s_me), FALSE);
   gtk_widget_set_margin_start(GTK_WIDGET (it_s_me), 20);
-  g_signal_connect (hello, "activate", G_CALLBACK (on_experimental_expander_toggled), it_s_me);
+  g_signal_connect (it_s_me, "activate", G_CALLBACK (on_experimental_expander_toggled), it_s_me);
   gtk_box_append (experimental_box, GTK_WIDGET (it_s_me));
 
   gtk_box_append (experimental_box, GTK_WIDGET(gtk_label_new ("\n\n")));
-
   return experimental_box;
 }
 

hot.h

@@ -12,5 +12,5 @@
 #include "display.h"
 #include "contain.h"
 
-GtkWidget *get_run_rules_page_new();
+
 GtkBox *get_experimental_box_new();

tree.c

@@ -263,9 +263,8 @@ static void ui_create_tree (GtkWidget *target_widget)
 
 GtkBox *get_rules_user_tree_new(){
   GtkBox *tree_sketch_box = GTK_BOX(gtk_box_new (GTK_ORIENTATION_VERTICAL, 0));
-  ui_create_tree (GTK_WIDGET (tree_sketch_box));
-
   gtk_box_append (tree_sketch_box, GTK_WIDGET (get_experimental_box_new()));
+  ui_create_tree (GTK_WIDGET (tree_sketch_box));
   return tree_sketch_box;
 }