Incremental diagram layout for automated model migration

Abstract

A range of successful modeling tools to develop complex systems use node-link-style diagrams as their underlying language. Over the years such languages can change, for instance as part of a tool update. When migrating existing models, changes in syntax directly affect the placement of elements in their diagrams. Increasing the size of certain nodes may for example result in node overlaps. In this paper we propose two methods based on graph drawing techniques to adjust the layout of existing diagrams after migration. Although we designed these techniques for diagram migration, they are applicable to other scenarios as well, such as users interactively adding or resizing nodes. We evaluate the techniques based on real world diagrams from the LabVIEW suite and discuss the scenarios each technique seems best suited for.

Pragmatics Twelve Years Later: A Report on Lingua Franca

“…And indeed, there have been several examples of tools that provided some auto-layout functionality produced rather unsatisfactory results. However, there also are positive examples, also in commercial tools; e. g., LabView has employed sophisticated layout algorithms in its "clean-up" functionality [39], which seems quite satisfactory (see also a quote citing LabView further below).…”

Layout Merging with Relative Positioning

“…When a graphical modeling language is updated, migrating existing models may lead to improper layout such as overlap of nodes. Rüegg et al [26] present a layout algorithm based on network simplex which rearranges the model elements to depict a proper layout, i.e., a layout that retains the original positioning of model elements after update. This work, unlike rpGraph, does not support the layout of a merged model during model reuse.…”

“…Second, a layout metamodel which can be used to depict models based on their relative positioning while leveraging existing automatic layout mechanisms such as GraphViz. This can be applied not only in model reuses but also in model adjustment [10,22,26]. And third, a layout algorithm that largely retains the layout of models when merged during reuse.…”

10 Reasons to Get Interested in Graph Drawing

“…Even though there seems to be a pretty clear case for the usage of graph drawing techniques to improve modeler productivity, as argued above, there is little pressure on the tool vendors to provide good solutions. Sometimes, however, there is no way around this; for example, when the visual syntax changes significantly from one tool version to the next, old models must be migrated automatically to the next version [68]. Also, while modelers are often unhappy with automatic layout results applied to "their" finished models that they have hand-crafted before, they seem much more open to automatic layout if it has been applied from the very beginning.…”