Constraint-based user interfaces for simulations

Many simulation environments lack modern user interfaces. This paper describes an approach to user interfaces that is very well suited for object-oriented simulation environments. Our approach views user interfaces as constraints that are maintained between separate objects. The contraints and the participating objects are modelled with a type language that captures the important aspects of an interface. Some of these aspects are the relationships and their types between various presentation objects. The type language can be produced graphically with the help of an interactive interface generator that can define and manipulate user interfaces to typed objects. The implementation of this interface generator does not disturb a running simulation and is based on constraint-satisfaction.