Event-driven grammars: Relating abstract and concrete levels of visual languages

The final publication is available at Springer via http://dx.doi.org/10.1007/s10270-007-0051-2In this work we introduce event-driven grammars, a kind of graph grammars that are especially suited for visual modelling environments generated by meta-modelling. Rules in these grammars may be triggered by user actions (such as creating, editing or connecting elements) and in their turn may trigger other user-interface events. Their combination with triple graph transformation systems allows constructing and checking the consistency of the abstract syntax graph while the user is building the concrete syntax model, as well as managing the layout of the concrete syntax representation. As an example of these concepts, we show the definition of a modelling environment for UML sequence diagrams. A discussion is also presented of methodological aspects for the generation of environments for visual languages with multiple views, its connection with triple graph grammars, the formalization of the latter in the double pushout approach and its extension with an inheritance concept.This work has been partially sponsored by the Spanish Ministry of Education and Science with projects MOSAIC (TSI2005-08225-C07-06) and MODUWEB (TIN 2006-09678)

Arcadia, a software development environment research project

The research objectives of the Arcadia project are two-fold: discovery and development of environment architecture principles and creation of novel software development tools, particularly powerful analysis tools, which will function within an environment built upon these architectural principles.Work in the architecture area is concerned with providing the framework to support integration while also supporting the often conflicting goal of extensibility. Thus, this area of research is directed toward achieving external integration by providing a consistent, uniform user interface, while still admitting customization and addition of new tools and interface functions. In an effort to also attain internal integration, research is aimed at developing mechanisms for structuring and managing the tools and data objects that populate a software development environment, while facilitating the insertion of new kinds of tools and new classes of objects.The unifying theme of work in the tools area is support for effective analysis at every stage of a software development project. Research is directed toward tools suitable for analyzing pre-implementation descriptions of software, software itself, and towards the production of testing and debugging tools. In many cases, these tools are specifically tailored for applicability to concurrent, distributed, or real-time software systems.The initial focus of Arcadia research is on creating a prototype environment, embodying the architectural principles, which supports Ada1 software development. This prototype environment is itself being developed in Ada.Arcadia is being developed by a consortium of researchers from the University of California at Irvine, the University of Colorado at Boulder, the University of Massachusetts at Amherst, TRW, Incremental Systems Corporation, and The Aerospace Corporation. This paper delineates the research objectives and describes the approaches being taken, the organization of the research endeavor, and current status of the work

Constraint specification by example in a Meta-CASE tool

CASE tools are very helpful to software engineers in different ways and in different phases of software development. However, they are not easy to specialise to meet the needs of particular application domains or particular software modelling requirements. Meta-CASE tools offer a way of providing such specialisation by enabling a designer to specify a tool which is then generated automatically. Constraints are often used in such meta-CASE tools as a technique for governing the syntax and semantics of model elements and the values of their attributes. However, although constraint definition is a difficult process it has attracted relatively little research attention. The PhD research described here presents an approach for improving the process of CASE tool constraint specification based on the notion of programming by example (or demonstration). The feasibility of the approach will be demonstrated via experiments with a prototype using the meta-CASE tool Diagram Editor Constraints System (DECS) as context

Formalizing graphical notations

The thesis describes research into graphical notations for software engineering, with a principal interest in ways of formalizing them. The research seeks to provide a theoretical basis that will help in designing both notations and the software tools that process them. The work starts from a survey of literature on notation, followed by a review of techniques for formal description and for computational handling of notations. The survey concentrates on collecting views of the benefits and the problems attending notation use in software development; the review covers picture description languages, grammars and tools such as generic editors and visual programming environments. The main problem of notation is found to be a lack of any coherent, rigorous description methods. The current approaches to this problem are analysed as lacking in consensus on syntax specification and also lacking a clear focus on a defined concept of notated expression. To address these deficiencies, the thesis embarks upon an exploration of serniotic, linguistic and logical theory; this culminates in a proposed formalization of serniosis in notations, using categorial model theory as a mathematical foundation. An argument about the structure of sign systems leads to an analysis of notation into a layered system of tractable theories, spanning the gap between expressive pictorial medium and subject domain. This notion of 'tectonic' theory aims to treat both diagrams and formulae together. The research gives details of how syntactic structure can be sketched in a mathematical sense, with examples applying to software development diagrams, offering a new solution to the problem of notation specification. Based on these methods, the thesis discusses directions for resolving the harder problems of supporting notation design, processing and computer-aided generic editing. A number of future research areas are thereby opened up. For practical trial of the ideas, the work proceeds to the development and partial implementation of a system to aid the design of notations and editors. Finally the thesis is evaluated as a contribution to theory in an area which has not attracted a standard approach

Gentleman : a lightweight web-based projectional editor

Lors de la conception et la manipulation de logiciel par modélisation, il est avantageux de bénéficier d’un grand degré de liberté au niveau de la présentation afin de comprendre l’information et prendre une action en exerçant peu d’effort cognitif et physique. Cette caractéristique doit aussi s’étendre aux outils que nous employons afin que ceux-ci augmentent nos capacités, plutôt que les restreindre. En génie logiciel, nous travaillons présentement à rehausser encore le niveau d’abstraction afin de réduire le rôle central du code décrit avec un langage de programmation à usage général. Ceci permettrait d’inclure les experts non techniques dans les activités de développement de logiciel. Cette approche, centralisée sur le domaine et l’expert, s’inscrit dans l’ingénierie dirigée par les modèles (IDM), où un modèle est produit et manipulé par divers experts et utilisateurs. Le modèle est alors décrit avec un langage créé spécifiquement pour un domaine d’application ou une tache, appelé langage dédié (DSL). Une technique utilisée pour créer ces modèles et leurs DSL est le projectional editing, qui permet d’utiliser des notations diverses interchangeables et d’étendre et composer facilement un langage. Toutefois, les solutions actuelles sont lourdes, spécifiques à une plateforme, et manquent considérablement d’utilisabilité, limitant ainsi l’usage et l’exploitation de cette approche. Pour mieux refléter les avantages du paradigme IDM avec le style projectionnel, nous introduisons dans cette thèse Gentleman, un éditeur projectionnel léger sur le web. Avec Gentleman, le développeur crée un modèle en combinant des concepts utilisés pour définir la structure du modèle et des projections pour les manipuler dans l’éditeur. Nous avons évalué Gentleman à travers une étude basée sur un groupe d’utilisateur. L’étude a confirmé sa capacité à créer et manipuler des modèles efficacement. Les participants ont noté qu’il est facile de prendre en main Gentleman et que l’interface est très intuitive comparativement aux éditeurs existants. Nous avons aussi intégré Gentleman avec succès à une plateforme web, démontrant ainsi ses capacités d’interopérabilité et l’avantage d’une solution web.In software activities and, more specifically, when modeling, the modeler should benefit from as much freedom as possible to understand the presented information and take action with minimal cognitive and mechanical effort. This characteristic should also apply to the tools used in the process so that they extend our capabilities rather than limit them. In the field of software engineering, current work aims to push the level of abstraction past general-purpose programming language into domain-specific modeling. This enables domain experts with various backgrounds to participate in software development activities. This vision is central to model-driven engineering (MDE) where, instead of code, various experts and users produce and manipulate domain-specific language (DSL). In recent years, projectional editing has proven to be a valid approach to creating and manipulating DSLs, as it supports various easily interchangeable notations and enables language extension and composition. However, current solutions are heavyweight, platform-specific, and suffer from poor usability. To better support this paradigm and minimize the risk of accidental complexity in terms of expressiveness, in this thesis, we introduce Gentleman, a lightweight web-based projectional editor. With Gentleman, a developer creates a model by combining concepts used to define its structure and projections to interact and manipulate them in the editor. We have evaluated Gentleman through a user study. The evaluation confirmed its capacity to create and manipulate models effectively. Most participants noted that the editor is very user-friendly and intuitive compared to existing editors. We have also successfully integrated Gentleman into a web application, demonstrating its interoperability and the benefit of a web solution

RULEBENDER: INTEGRATED MODELING, SIMULATION, AND VISUALIZATION FOR RULE-BASED INTRACELLULAR BIOCHEMISTRY

Rule-based modeling (RBM) is a powerful and increasingly popular approach to modeling cell signaling networks. However, novel visual tools are needed in order to make RBM accessible to a broad range of users, to make specification of models less error prone, and to improve workflows. We introduce RuleBender, a novel visualization system for the integrated visualization, modeling and simulation of rule-based intracellular biochemistry. We present the user requirements, visual paradigms, algorithms and design decisions behind RuleBender, with emphasis on visual global/local model exploration and integrated execution of simulations. The support of RBM creation, debugging, and interactive visualization expedites the RBM learning process and reduces model construction time; while built-in model simulation and results with multiple linked views streamline the execution and analysis of newly created models and generated networks. RuleBender has been adopted as both an educational and a research tool and is available as a free open source tool at http://www.rulebender.org. A development cycle that includes close interaction with expert users allows RuleBender to better serve the needs of the systems biology community