FlexClock, a Plastic Clock Written in Oz with the QTk toolkit

This paper focuses on the techniques involved in building an interactive application using a plastic user interface. These techniques take advantage of the QTk toolkit, a toolkit that features innovative and powerful concepts when compared to more classical object-oriented toolkits. These features are possible thanks to the underlying programming language used, Oz, and in particular: a. its support to symbolic records that can express data structures in a similar yet more complete way than XML. b. its capacity to wrap any languages entities into higher order data structures. This paper shows by a case study how the combination of QTk and Oz helps developers write plastic user interfaces very easily.