Rollit: An Application Builder

Contemporary user interface development systems greatly simplify the creation of traditional dialogue user interface made of buttons or menus, but they do not support the construction and manipulation of application-specific graphical objects. This report describes Rollit, a domain-specific, interactive, application builder. The goal of this system is to automatically generate, as a result of direct manipulation, the domain-specific user interface and its run-time behavior as well as the traditional dialogue user interface. Application programmers construct complex objects from standard components, define the interactions between those objects and attach behaviors to them. A constraint-based inference system facilitates the definition of geometrical constraints between objects. Our run-time system kernel supports standard operations on those objects, such as creation and deletion, cut and paste, grouping, save and load. This report describes our system, illustrates its usefulness through applications built within our environment, and shows how it reduces the effort required to develop such applications.