WIP: ^c^v pas à pas, suite (DON'T read this commit)

src/ui/sand_box.c

@@ -29,9 +29,61 @@
 #include "../../include/ui.h"
 
 static void and_now_let_s_climb_that_tree (GtkWidget *in_that_box);
-static void on_bind_list_item_cb (GtkListItemFactory* factory, GtkListItem* list_item, gpointer user_data){}
+
-static void on_setup_list_item_cb (GtkListItemFactory* factory, GtkListItem* list_item, gpointer user_data){}
+// This function is a placeholder. You need to implement the logic based on your tree structure.
+static GListModel* create_child_model (const gchar* parent) {
+    GtkStringList* list = gtk_string_list_new (NULL);
+    if (g_strcmp0 (parent, "Parent Item 1") == 0) {
+        gtk_string_list_append (list, "Child 1.1");
+        gtk_string_list_append (list, "Child 1.2");
+    } else if (g_strcmp0 (parent, "Parent Item 2") == 0) {
+        gtk_string_list_append (list, "Child 2.1");
+    }
+    return G_LIST_MODEL (list);
+}
+
 static void on_destroy (GtkWidget *widget, gpointer data) {if (data) g_print (data);  exit (0);}
+
+static void on_bind_list_item_cb (GtkListItemFactory* factory, GtkListItem* list_item, gpointer user_data)
+{
+    GObject* item = gtk_list_item_get_item (list_item);
+    if (!item) return; // Necessary check
+
+    const gchar* text = gtk_string_object_get_string (GTK_STRING_OBJECT (item));
+
+    GtkWidget* label = gtk_label_new (text);
+    GtkWidget* expander = gtk_list_item_get_child (list_item);
+    gtk_tree_expander_set_child (GTK_TREE_EXPANDER (expander), label);
+
+    // Determine if this item should have an expander (i.e., if it has children)
+    GListModel* child_model = create_child_model (text);
+    if (child_model) gtk_tree_expander_set_expanded (GTK_TREE_EXPANDER (expander), TRUE);
+    g_object_unref (child_model); // Cleanup
+}
+
+static void on_setup_list_item_cb (GtkListItemFactory* factory, GtkListItem* list_item, gpointer user_data) {
+    GtkWidget* expander = gtk_tree_expander_new ();
+    gtk_list_item_set_child (list_item, expander);
+}
+
+static GtkTreeListModel* create_tree_list_model () {
+    // Initial parent items
+    GtkStringList* base_model = gtk_string_list_new (NULL);
+    gtk_string_list_append (base_model, "Parent Item 1");
+    gtk_string_list_append (base_model, "Parent Item 2");
+
+    // Create a GtkTreeListModel that uses our function to fetch children for each parent
+    GtkTreeListModel* tree_model = gtk_tree_list_model_new (
+                                              GTK_SELECTION_MODEL (gtk_no_selection_new (G_LIST_MODEL (base_model))),
+                                              TRUE,  // True to check for child items
+                                              0,
+                                              (GtkTreeListModelCreateModelFunc) create_child_model,
+                                              NULL,  // user data
+                                              g_object_unref);
+// cleanup function for user data
+    return tree_model;
+}
+
 static void on_app_activate (GApplication* app, gpointer user_data) {
     GtkWidget* window = gtk_application_window_new (GTK_APPLICATION (app));
     gtk_window_set_title (GTK_WINDOW (window), "GTK4 Tree Example");