Interaction in Really Graphical User Interfaces

Employing diagrams in the UI causes problems that don't exist in so called G r aphical User Interfaces. We are implementing a tool for generating editors for a certain class of diagrams from a speciication. Diagram Editors are n e e ded i n r e ally graphical UIs and interactive visual language environments. This paper addresses three aspects of the speciication of diagram editors. After highlighting diiculties in user interaction with diagrams event automata are suggested as a model for speciication of dialogs. Furthermore, it is discussed how objects selected by the user can automatically be assembled into semantically meaningful groups. These are needed for more c omplex editing operations. An e asy and versatile way of specifying layout for diagram editors by constraints has been introduced in 11 and is generalized here.