Project DIGIS: Building Interactive Applications by Direct Manipulation

Abstract

AbstractDIGIS is a design and implementation system for developers of general purpose interactive applications (IA). It is itself an interactive system that accomplishes its task by Direct Manipulation techniques, in principle without using a programming language. DIGIS is a generator in the form of a window-based workbench. It has two input sources. One is a toolkit of predetined interaction tools consisting of prototypes and instances. The other is the set of predetined application procedures thai make up the application part of the IA. The application procedures do not handle user input but may handle textual or graphical screen output. The task of the developer is to build the user interface by selecting the appropriate interaction tools. tailor them to the interface, and tie them to application procedures. This includes the visual representations of interaction tools, their prompts, echoes and feedback. In the process he maps user input to parameter lists for the application procedures, and return parameters to interface output. DIGIS will also support the detinition of composite input (interaction patterns such as sequences). Unix and X are the initiat operating environment, adaption of the input sources to PCTE. OSF/Motif, and Open Look is feasible and anticipated.The design of DIGIS is based on a hierarchical interaction model that is the second focus of this paper. The implementation will be done using PROCOL, a locally developed concurrent object-oriented language. which offers protocols that support composite input. The language is a superset of C, and therefore fully compatible with existing C libraries.ACM Categories and Subject Descriptors: D.2.2 [Software Engineering]: Tools and Techniques -user interfaces, programmer workbench-D.3.3 [Programming Language]: Language Constructs -input/output, programming structures-H.1.2 [Models and Principles]: User/Machine Systems -human factors-1.3.6 [Computer Graphics]: Methodology and Techniques - interaction techniques, ergonomics, languages: