Animated graphical interfaces using temporal constraints

Algorithm animation has an acknowledged and growing role in computer aided algorithm design, as well as in documentation and technology transfer, since the medium of interactive graphics is a broader, richer channel than text by which to communicate information. Since an animation constitutes the interface between a user and an algorithm, a kit that facilitates the construction of such has all the basic elements of a User Interface Management System. Constraint languages are useful in constructing such an interface construction kit, whereby consistency is maintained among the elements of a structure and among those of a view of that structure presented to the user. But constraints specify only static state in current implementations. To specify the evolution of structures and views by discrete time increments, as in animation, requires a extension to current constraint languages to allow expression of specifications of temporal behavior.