An application containing a Graphical User Interface (GUI) should be divided into application, translation and presentation parts.
A State Transition Diagram (STD) contains an explicit specification of the interface which is to be constructed.
The physical appearance of an interface can be used to produce an application instance hierarchy which identifies the components required.
An applet is constructed by extending the Applet class and its interface can be constructed by overriding the Applet init() method.
Container classes, which include Panels, Frames and Applets, control the layout of their instance children using a layout policy.
The translation class has to implement a suitable Listener interface and be registered with an interactive component as its listener in order for it to respond to the user's actions.
The STD should be modelled in the translation class and call state-changing methods in the presentation class as appropriate.
An applet can be executed in a browser without a main() method, but a main() method must be supplied for it to be run as a stand alone application.