rem: g_signal_connect (selection, "changed", G_CALLBACK (selection_cb), preference_tree_model);
add: g_signal_connect (selection, "changed", G_CALLBACK (selectionne_liste_preference), preference_tree_model);
context: GtkWidget * create_preferences_tree(){  GtkWidget *tree, *item;  GList *items = NULL;  GtkTreeIter iter;  GtkTreeViewColumn *column;  GtkCellRenderer *cell;  preference_tree_model = gtk_tree_store_new (2, 					      G_TYPE_STRING, 					      G_TYPE_POINTER);  tree = gtk_tree_view_new();  gtk_tree_view_set_model (GTK_TREE_VIEW (tree), GTK_TREE_MODEL (preference_tree_model));  selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (tree));/*   gtk_tree_store_append (GTK_TREE_STORE (model), &iter, NULL); *//*   gtk_tree_store_set (GTK_TREE_STORE (model), *//* 		      &iter, *//* 		      0, "Un", *//* 		      1, "plip", *//* 		      -1); *//*   gtk_tree_store_append (GTK_TREE_STORE (model), &iter, NULL); *//*   gtk_tree_store_set (GTK_TREE_STORE (model), *//* 		      &iter, *//* 		      0, "Deux", *//* 		      1, "plop", *//* 		      -1); */  cell = gtk_cell_renderer_text_new ();  column =     gtk_tree_view_column_new_with_attributes ("Categories",					      cell,					      "text", 0,					      NULL);  gtk_tree_view_append_column (GTK_TREE_VIEW (tree),			       GTK_TREE_VIEW_COLUMN (column));    g_signal_connect (selection, "changed", G_CALLBACK (selection_cb), preference_tree_model);  return tree;}