In general, HTKhas a couple of abstract datatypes used to model
elements of the graphical user interface, such as buttons, menus,
short text fields, longer texts, and so on. Recall from
Section 1.2 above that there is an abstract datatype
Button, elements of which are created with the function
This takes a parent GUI element, and a list of configurations as parameter. We will first examine the class Container, which models the GUI element hierarchy, and then the configurations, followed by resources such as fonts and colours. At the end of this section, we explain packing.