A Static Layout Algorithm for DiaMeta

The diagram editor generator framework DiaMeta utilizes meta-model-based language specifications and supports free-hand as well as structured editing. In this paper we present a layouting approach that is especially well suited for a static layout. It is based on the layout algorithm presented in a previous paper that uses the two concepts constraint satisfaction and attribute evaluation. This algorithm is combined with graph transformations and the result is a natural way of describing the layout of visual languages. As an example we use a simplified version of Sugiyama's algorithm, applied to statechart diagrams

Layout Specification on the Concrete and Abstract Syntax Level of a Diagram Language

A visual language consists of several visual component types, e.g. states or transitions in DFAs. Nowadays, the language itself is usually specified via a meta model. To make a diagram look nice, a layouter is required. This layouter may either operate on the concrete syntax level, i.e., on the visual components, or on the abstract syntax level, i.e., on the model instance. In this paper we present an approach that is capable of specifying a flexible layout on both, the concrete as well as the abstract syntax level of a diagram. The approach uses pattern-based transformations. Besides structured editing, it also supports free-hand editing, a challenging task for the layouter. We introduce how such a specification can be created and examine the advantages and shortcomings of each of either operating on the concrete syntax level or on the abstract syntax level

A cognitive exploration of the “non-visual” nature of geometric proofs

Why are Geometric Proofs (Usually) “Non-Visual”? We asked this question as a way to explore the similarities and differences between diagrams and text (visual thinking versus language thinking). Traditional text-based proofs are considered (by many to be) more rigorous than diagrams alone. In this paper we focus on human perceptual-cognitive characteristics that may encourage textual modes for proofs because of the ergonomic affordances of text relative to diagrams. We suggest that visual-spatial perception of physical objects, where an object is perceived with greater acuity through foveal vision rather than peripheral vision, is similar to attention navigating a conceptual visual-spatial structure. We suggest that attention has foveal-like and peripheral-like characteristics and that textual modes appeal to what we refer to here as foveal-focal attention, an extension of prior work in focused attention

Exploiting the Layout Engine to Assess Diagram Completions

A practicable approach to diagram completion is to first compute model completions on the abstract syntax level. These can be translated to corresponding diagram changes by the layout engine afterwards. Normally, several different model completions are possible though. One way to deal with this issue is to let the user choose among them explicitly, which is already helpful. However, such a choice step is a quite time-consuming interruption of the editing process. We argue that users often are mainly interested in completions that preserve their original diagram as far as possible. This criterion cannot be checked on the abstract syntax level though. In fact, minimal model changes might still result in enormous changes of the original diagram. Therefore, we suggest to use the layout engine in advance for assessing all possible model completions with respect to the diagram changes they eventually cause

Automatisches Zeichnen von Graphen für modellgetriebene Softwareentwicklung

As shown previously by Fuhrmann, there are several concepts for increasing the productivity of MDE by improving the practical handling of models. The automatic layout of graph-based models is a key enabler in this context. However, there is a striking contrast between the abundance of research results in the field of graph layout methods and the current state of graphical modeling tools, where only a tiny fraction of these results are ever adopted. This thesis aims to bridge this gap on three separate levels: specialized layout algorithms, configuration management, and software infrastructure. Regarding layout algorithms, here we focus on the layer-based approach. We examine its extension to include ports and hyperedges, which are essential features of certain kinds of graphs, e.g. data flow models. The main contribution is the handling of constraints on the positioning of ports, which is done mainly in the crossing minimization and edge routing phases. Hyperedges are represented with normal edges, simplifying their handling but introducing inaccuracies for counting crossings. A final extension discussed here is a sketch-driven approach for simple integration of user interactivity. An abstract layout is the selection of a layout algorithm with a mapping of its parameters to specific values. We discuss a new meta model allowing to specify the structure of a graph as well as its abstract layout and its concrete layout, i.e. positioning data computed by the layout algorithm. This forms a basis for efficient management of layout configurations. Furthermore, we investigate an evolutionary algorithm for searching the solution space of abstract layouts, taking readability criteria into account for evaluating solutions. The software infrastructure developed here targets the connection of arbitrary diagram viewers (front-ends) with arbitrary graph layout algorithms (back-ends). The main challenge is to find suitable abstractions that allow such generality and at the same time keep the complexity as low as possible. We discuss a possible realization based on the Eclipse platform, which is used by several modeling tools, e.g. the Graphical Modeling Framework. A web-based survey has been conducted among users of the layout infrastructure in order to evaluate to what extent the stated goals have been met. The overall feedback collected from this survey is very positive.Wie bereits von Fuhrmann gezeigt, kann die Produktivität modellgetriebener Softwareentwicklung durch zahlreiche Konzepte zur Verbesserung der praktischen Handhabung von Modellen erhöht werden. Dabei ist das automatische Layout graphenbasierter Modelle ein zentraler Schlüssel. Allerdings gibt es einen bemerkenswerten Kontrast zwischen der Fülle an Forschungsergebnissen im Bereich des Graphen-Layout und dem aktuellen Stand graphischer Modellierungswerkzeuge, bei denen nur ein kleiner Teil dieser Ergebnisse übernommen wird. Das Ziel dieser Arbeit ist diese Lücke auf drei separaten Ebenen zu überbrücken: spezialisierte Layout-Algorithmen, Verwaltung von Konfigurationen und Software-Infrastruktur. Im Bezug auf Layout-Algorithmen liegt der Schwerpunkt auf dem Layer-basierten Ansatz. Wir untersuchen dessen Erweiterung zur Unterstützung von Ports und Hyperkanten, was wesentliche Bestandteile bestimmter Arten von Graphen sind, z.B. Datenflussmodelle. Der Hauptbeitrag ist die Einbeziehung von Bedingungen für die Positionierung von Ports, vor allem während der Kreuzungsminimierung und der Kantenführungsphase. Hyperkanten werden durch normale Kanten repräsentiert, was deren Verarbeitung vereinfacht aber Ungenauigkeiten beim Zählen von Kreuzungen verursacht. Als letzte Erweiterung betrachten wir einen Sketch-basierten Ansatz für die einfache Integration von Nutzerinteraktivität. Ein abstraktes Layout ist die Auswahl eines Layout-Algorithmus zusammen mit einer Abbildung seiner Parameter auf konkrete Werte, während ein konkretes Layout Positionsdaten beschreibt, die von einem Algorithmus berechnet wurden. Wir diskutieren ein neues Metamodell, mit dem sowohl die Struktur als auch das abstrakte sowie das konkrete Layout eines Graphen spezifiziert werden kann. Dies bildet eine Grundlage für die effiziente Verwaltung von Layout-Konfigurationen. Zudem untersuchen wir einen evolutionären Algorithmus für die Suche im Lösungsraum abstrakter Layouts, wobei zur Bewertung von Lösungen Ästhetikkriterien ausgewertet werden. Die in dieser Arbeit entwickelte Software-Infrastruktur hat als Ziel, beliebige Graphen-basierte Diagramme (front-ends) mit beliebigen Layout-Algorithmen (back-ends) zu verbinden. Die größte Herausforderung dabei ist das Finden geeigneter Abstraktionen, die eine solche Allgemeingültigkeit erlauben und gleichzeitig die Komplexität so niedrig wie möglich halten. Wir betrachten eine mögliche Realisierung, die auf Eclipse basiert, eine von vielen Modellierungswerkzeugen verwendete Plattform. Eine Web-basierte Umfrage wurde unter Nutzern der Layout-Infrastruktur durchgeführt, um zu untersuchen inwieweit die gesteckten Ziele erfüllt worden sind. Die allgemeine Resonanz zu dieser Umfrage ist sehr positiv

ProMeTA: A taxonomy for program metamodels in program reverse engineering

ABSTRACT: To support program comprehension, maintenance, and evolution, metamodels are frequently used during program reverse engineering activities to describe and analyze constituents of a program and their relations. Reverse engineering tools often define their own metamodels according to the intended purposes and features. Although each metamodel has its own advantages, its limitations may be addressed by other metamodels. Existing works have evaluated and compared metamodels and tools, but none have considered all the possible characteristics and limitations to provide a comprehensive guideline for classifying, comparing, reusing, and extending program metamodels. To aid practitioners and researchers in classifying, comparing, reusing, and extending program metamodels and their corresponding reverse engineering tools according to the intended goals, we establish a conceptual framework with definitions of program metamodels and related concepts. We confirmed that any reverse engineering activity can be clearly described as a pattern based on the framework from the viewpoint of program metamodels. Then the framework is used to provide a comprehensive taxonomy, named Program Metamodel TAxonomy (ProMeTA), which incorporates newly identified characteristics into those stated in previous works, which were identified via a systematic literature review (SLR) on program metamodels, while keeping the orthogonality of the entire taxonomy. Additionally, we validate the taxonomy in terms of its orthogonality and usefulness through the classification of popular metamodels

Über die Pragmatik der Graphischen Modellierung

Graphical models help to understand complex systems. However, with the user interaction paradigms established today, activities such as creating, maintaining or browsing graphical models can be very tedious. This thesis presents an approach to enhance productivity by focusing on the pragmatics of model-based design. The contribution includes an interpretation of the notion of pragmatics, orthogonal to syntax and semantics in Model-Driven Engineering (MDE). A proposal on pragmatics-aware modeling is given, employing sophisticated automated layout algorithms to close the gap between MDE and graph drawing theory. Thus, a view management logic presents customized views on models. These concepts get illustrated with the open source Kiel Integrated Environment for Layout Eclipse Rich Client (KIELER) with multiple applications including editing and simulation and shows how view management helps to tame complexity

Languages of games and play: A systematic mapping study

Digital games are a powerful means for creating enticing, beautiful, educational, and often highly addictive interactive experiences that impact the lives of billions of players worldwide. We explore what informs the design and construction of good games to learn how to speed-up game development. In particular, we study to what extent languages, notations, patterns, and tools, can offer experts theoretical foundations, systematic techniques, and practical solutions they need to raise their productivity and improve the quality of games and play. Despite the growing number of publications on this topic there is currently no overview describing the state-of-the-art that relates research areas, goals, and applications. As a result, efforts and successes are often one-off, lessons learned go overlooked, language reuse remains minimal, and opportunities for collaboration and synergy are lost. We present a systematic map that identifies relevant publications and gives an overview of research areas and publication venues. In addition, we categorize research perspectives along common objectives, techniques, and approaches, illustrated by summaries of selected languages. Finally, we distill challenges and opportunities for future research and development

Definition of a Type System for Generic and Reflective Graph Transformations

This thesis presents the extension of the graph transformation language SDM (Story Driven Modeling) with generic and reflective features as well as the definition of type checking rules for this language. The generic and reflective features aim at improving the reusability and expressiveness of SDM, whereas the type checking rules will ensure the type-safety of graph transformations. This thesis starts with an explanation of the relevant concepts as well as a description of the context in order to provide the reader with a better understanding of our approach. The model driven development of software, today considered as the standard paradigm, is generally based on the use of domain-specific languages such as MATLAB Simulink and Stateflow. To increase the quality, the reliability,and the efficiency of models and the generated code, checking and elimination of detected guideline violations defined in huge catalogues has become an essential, but error-prone and time-consuming task in the development process. The MATE/MAJA projects, which are based on the use of the SDM language, aim at an automation of this task for MATLAB Simulink/Stateflow models. Modeling guidelines can be specified on a very high level of abstraction by means of graph transformations. Moreover, these specifications allow for the generation of guideline checking tools. Unfortunately, most graph transformation languages do not offer appropriate concepts for reuse of specification fragments - a MUST, when we deal with hundreds of guidelines. As a consequence we present an extension of the SDM language which supports the definition of generic rewrite rules and combines them with the reflective programming mechanisms of Java and the model repository interface standard JMI. Reusability and expressiveness are not the only aspects we want to improve. Another fundamental aspect of graph transformations must be ensured: their correctness in order to prevent type errors while executing the transformations. Checking and testing the graph transformations manually would ruin the benefit obtained by the automation of the guideline checking and by the generic and reflective features. Therefore, we propose in this work a type-checking method for graph transformations. We introduce a new notation for rules of inference and define a type system for SDM. We also proposed an algorithm to apply this type system. We illustrate and evaluate both contributions of our work by applying them on running examples. Proposals for other additional SDM features as well as for possible improvements of our type checking open new perspectives and future research to pursue our work

Engineering scalable modelling Languages

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Ingeniería Informática. Fecha de lectura: 08-11-2019Esta tesis tiene embargado el acceso al texto completo hasta el 08-05-2021Model-Driven Engineering (MDE) aims at reducing the cost of system development by raising the level of abstraction at which developers work. MDE-based solutions frequently involve the creation of Domain-Specific Modelling Languages (DSMLs). WhilethedefinitionofDSMLsandtheir(sometimesgraphical)supportingenvironments are recurring activities in MDE, they are mostly developed ad-hoc from scratch. The construction of these environments requires high expertise by developers, which currently need to spend large efforts for their construction. This thesis focusses on the development of scalable modelling environments for DSMLs based on patterns. For this purpose, we propose a catalogue of modularity patterns that can be used to extend a modelling language with services related to modularization and scalability. More specifically, these patterns allows defining model fragmentation strategies, scoping and visibility rules, model indexing services, and scoped constraints. Once the patterns have been applied to the meta-model of a modelling language, we synthesize a customized modelling environment enriched with the defined services, which become applicable to both existing monolithic legacy models and new models. A second contribution of this thesis is a set of concepts and technologies to facilitate the creation of graphical editors. For this purpose, we define heuristics which identify structures in the DSML abstract syntax, and automatically assign their diagram representation. Using this approach, developers can create a graphical representation by default from a meta-model, which later can be customised. These contributions have been implemented in two Eclipse plug-ins called EMFSplitter and EMF-Stencil. On one hand, EMF-Splitter implements the catalogue of modularity patterns and, on the other hand, EMF-Stencil supports the heuristics and the generation of a graphical modelling environment. Both tools were evaluated in different case studies to prove their versatility, efficiency, and capabilitieEl Desarrollo de Software Dirigido por Modelos (MDE, por sus siglas en inglés) tiene como objetivo reducir los costes en el desarrollo de aplicaciones, elevando el nivel de abstracciónconelqueactualmentetrabajanlosdesarrolladores. Lassolucionesbasadas en MDE frecuentemente involucran la creación de Lenguajes de Modelado de Dominio Específico (DSML, por sus siglas en inglés). Aunque la definición de los DSMLs y sus entornos gráficos de modelado son actividades recurrentes en MDE, actualmente en la mayoría de los casos se desarrollan ad-hoc desde cero. La construcción de estos entornos requiere una alta experiencia por parte de los desarrolladores, que deben realizar un gran esfuerzo para construirlos. Esta tesis se centra en el desarrollo de entornos de modelado escalables para DSML basados en patrones. Para ello, se propone un catálogo de patrones de modularidad que se pueden utilizar para extender un lenguaje de modelado con servicios relacionados con la modularización y la escalabilidad. Específicamente, los patrones permiten definir estrategias de fragmentación de modelos, reglas de alcance y visibilidad, servicios de indexación de modelos y restricciones de alcance. Una vez que los patrones se han aplicado al meta-modelo de un lenguaje de modelado, se puede generar automáticamente un entorno de modelado personalizado enriquecido con los servicios definidos, que se vuelven aplicables tanto a los modelos monolíticos existentes, como a los nuevos modelos. Una segunda contribución de esta tesis es la propuesta de conceptos y tecnologías para facilitar la creación de editores gráficos. Para ello, definimos heurísticas que identifican estructuras en la sintaxis abstracta de los DSMLs y asignan automáticamente su representación en el diagrama. Usando este enfoque, los desarrolladores pueden crear una representación gráfica por defecto a partir de un meta-modelo. Estas contribuciones se implementaron en dos plug-ins de Eclipse llamados EMFSplitter y EMF-Stencil. Por un lado, EMF-Splitter implementa el catálogo de patrones y, por otro lado, EMF-Stencil implementa las heurísticas y la generación de un entorno de modelado gráfico. Ambas herramientas se han evaluado con diferentes casos de estudio para demostrar su versatilidad, eficiencia y capacidade