Generating Editors for Direct Manipulation of Diagrams

. Diagrams (e.g., trees for hierarchical structures, or graphs for finite state machines) are often needed as part of advanced user interfaces, and are frequently specific to a user's application. The implementation of editors for diagramsshouldbe supported by a tool andbasedona formal model. This paper gives an overview of DiaGen, our generator for diagram editors. An editor for a certain kind of diagram is generated from a specification, which includes a grammar to describe the structure of diagrams. The user of a diagram editor, however, does not have to be concerned with the grammar, but can manipulate diagrams very conveniently by direct manipulation. 1 Introduction Today's Graphical User Interfaces (GUIs) are usually not very graphical, an assessment also made in a recent CACM issue on GUIs [1]: What the market considers a GUI is little more than a glorified menu system, having no graphics. This leaves the graphical representation of the application domain as an exercise for th..