Selecting screens in a GUI using events generated by a set of view controllers

A method and apparatus in a data processing system for presenting a set of screens in a graphical user interface. A first screen within a set of screens is presented, wherein the set of screens are presented using a set of view controllers. Responsive to a selected user input to the first screen, an event is generated by a view controller within the set of view controllers identifying the user input to the first screen, which is handled by the first view controller. Responsive to detecting the event generated by the view controller, a second screen from the set of screens is selected, by an application mediator, for display by sending a response to a view controller handling the second screen. The application mediator is initialized from reading a state machine file and control processing of view event received from virtual controllers.