Formal methods are increasingly accepted for developing software systems, however their application to user-interface development is less common. In this thesis, we demonstrate the utility of formal object-oriented techniques for specifying, designing and implementing user-interfaces. The specification of a user-interface describes user-perceivable operations and information structures for an interactive system in an implementation-independent way. Operations of a user-interface specification define tasks. User-interfaces can be specified by a system of communicating agents where some agents are presented to users. An agent and its presentation together define an interactor. Defining the presentation of interactors is a design concern. Widgets are common re-usable interactors for which the presentation is usually well defined. Definitions of widgets may be stored in a library. We illustrate the characteristics of notations for interactor based specification using the Object-Z language and demonstrate using interactors from a widget library. Formal methods enable a "model-based" approach to be taken to the development of user-interface designs. A specification in terms of widgets is derivable from an abstract interactor-based specification. A corresponding user-interface design is usually easily identified from a widget-based specification. Interactor-based user-interface designs can be used to define an architecture for a corresponding system implementation. Derivation of a widget-based specification from an abstract specification corresponds to a task decomposition (i.e., the abstract and widget-based specifications enable the same tasks to be performed, although the operations involved differ). Task decomposition defines a compatibility relation between user-interface specifications. We give "specification patterns" to assist incrementally transforming an abstract user-interface specification to an equivalent specification in terms of widgets.
Identifer | oai:union.ndltd.org:ADTP/253795 |
Creators | Hussey, Andrew Patrick |
Source Sets | Australiasian Digital Theses Program |
Detected Language | English |
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