Statechart Development Beyond WYSIWYG

Abstract

Abstract. Modeling systems based on semi-formal graphical formalisms, such as Statecharts, have become standard practice in the design of reactive embedded devices. Statecharts are often more intuitively understandable than equivalent textual descriptions, and their animated simulation can help to visualize complex behaviors. However, in terms of editing speed, project management, and meta-modeling, textual descriptions have advantages. As alternative to the standard WYSIWYG editing paradigm, we present an approach that is also graphical but oriented on the underlying structure of the system under development, and another approach based on a textual, dialect-independent Statechart description language. These approaches have been implemented in a prototypical modeling tool, which encompasses automatic Statechart layout. An empirical study on the usability and practicability of our Statechart editing techniques, including a Statechart layout comparison, indicates significant performance improvements in terms of editing speed and model comprehension compared to traditional modeling approaches.

Port Constraints in Hierarchical Layout of Data Flow Diagrams

“…KIELER is a platform for experimental approaches to graphical model-based design and for combination of different aspects of graphical modeling, such as methods of model editing, visualization of simulation, and automatic layout. Unlike its preceding project, the Kiel Integrated Environment for Layout (KIEL), which was developed as a stand-alone Java application [13], KIELER builds on Eclipse, an extensible platform comprised of various integrated development environments. Our Eclipse interface enables the layout functionality for editors of the Eclipse …”

On the Pragmatics of Model-Based Design

“…This was employed for Statecharts as shown in Fig. 2(b) using the layered based Sugiyama layouter of the GraphViz library in the KIEL project [3]. Small enhancements of the graphical syntax might have severe consequences for the layout.…”

“…Focus and Context in KIEL The Kiel Integrated Environment for Layout (KIEL) project [3] uses a semantical graphical focus and context technique to hide details in the context while highlighting the focus. It is semantical, because the decision of objects to be filtered is made automatically from semantic background information from the model [27].…”

“…For example, there are fundamental practical differences in using textual or graphical languages [1], and freeing the modeler from the burden of manually drawing a graphical model opens the door to a number of productivity-enhancing techniques that allow to combine the best of both worlds [3]. Furthermore, there are already a number of paradigms well established in software engineering that could be put to use for model-based design processes, including the design of the modeling infrastructure itself.…”

Finite State Machines and Modal Models in Ptolemy II

“…Alur et al (1999) give a very nice study of semantic questions around concurrent FSMs, including various complexity questions. Prochnow and von Hanxleden (2007) describe sophisticated techniques for visual editing of concurrent state machines. …”