Theobject represents a value which has an associated lower and upper bound, together with step and page increments, and a page size. It is used within several GTK+ widgets, including , , and (which is a base class for , , , and ). The object does not update the value itself. Instead it is left up to the owner of the to control the value. The owner of the typically calls the gtk_adjustment_value_changed() and gtk_adjustment_changed() functions after changing the value and its bounds. This results in the emission of the or signal respectively.