GtkTreeSortable The interface for sortable models used by GtkTreeView #GtkTreeSortable is an interface to be implemented by tree models which support sorting. The #GtkTreeView uses the methods provided by this interface to sort the model. #GtkTreeModel, #GtkTreeView @treesortable: the object which received the signal. @g_iface: @sort_column_changed: @get_sort_column_id: @set_sort_column_id: @set_sort_func: @set_default_sort_func: @has_default_sort_func: A GtkTreeIterCompareFunc should return a negative integer, zero, or a positive integer if @a sorts before @b, @a sorts with @b, or @a sorts after @b respectively. If two iters compare as equal, their order in the sorted model is undefined. In order to ensure that the #GtkTreeSortable behaves as expected, the GtkTreeIterCompareFunc must define a partial order on the model, i.e. it must be reflexive, antisymmetric and transitive. For example, if @model is a product catalogue, then a compare function for the "price" column could be one which returns price_of(@a) - price_of(@b). @model: The #GtkTreeModel the comparison is within @a: A #GtkTreeIter in @model @b: Another #GtkTreeIter in @model @user_data: Data passed when the compare func is assigned e.g. by gtk_tree_sortable_set_sort_func() @Returns: @sortable: @sortable: @sort_column_id: @order: @Returns: @sortable: @sort_column_id: @order: @sortable: @sort_column_id: @sort_func: @user_data: @destroy: @sortable: @sort_func: @user_data: @destroy: @sortable: @Returns: