Difference between revisions of "GEF/GEF4/DOT"

Revision as of 08:21, 28 January 2016

Note to non-wiki readers: This documentation is generated from the Eclipse wiki - if you have corrections or additions it would be awesome if you added them in the original wiki page.

Introduction

The GEF4 DOT component provides support for Graphviz DOT, in terms of

• an Xtext-based .dot file editor
• support for Graphviz-based generation of PDF-output for .dot files
• a GEF4 Zest-based DOT Graph Viewer
• API to import/export DOT to/from GEF4 Graph representations (which can be visualized with GEF4 Zest)

It is internally decomposed into two modules, namely DOT and DOT.UI. There are also a couple of undeployed DOT Examples. The user documentation is provided in terms of the GEF4 DOT User Guide.

This component was started as a project in the Google Summer of Code 2009 by Fabian Steeg, mentored by Ian Bull, for Zest. It was initially included in Zest 2 and has finally been migrated to GEF4 DOT, being now based on GEF4 Graph, GEF4 Layout, and GEF4 Zest.

DOT

• feature: org.eclipse.gef4.dot
• bundle: org.eclipse.gef4.dot

The DOT module of GEF4 DOT provides support for importing (DotImport) and exporting (DotExport) Graphviz DOT to/from a GEF4 Graph-based model. The GEF4 Graph-based model uses Graphviz specific properties, which are defined in DotProperties.

{Root}

• package: org.eclipse.gef4.dot

The {Root} package provides an importer (DotImport) and exporter (DotExport) between a Graphviz DOT and a related GEF4 Graph representation. The imported or to be exported graph has to make use of the properties defined in DotProperties.

DotImport

DotImport provides support for importing a Graphviz DOT into a GEF4 Graph data model, using the properties defined in DotProperties.

/* We can create Graphs based on Graphviz Dot files and strings */
Graph graph = new DotImport("graph { 1--2 ; 1--3 }").newGraphInstance();
Graph digraph = new DotImport("digraph { 1->2 ; 1->3 }").newGraphInstance();
 
/* We can also import Graphviz Dot files/string into an existing graph */
Graph.Builder graph2 = new Graph.Builder();
new DotImport("digraph{1->2}").into(graph2);
new DotImport("node[label=zested]; 2->3; 2->4").into(graph2);
new DotImport("edge[style=dashed]; 3->5; 4->6").into(graph2);

The complete sample usage is available in the repository, more input samples can be found here.

Internally, DotImport is based on an Xtext-based parser. It uses the generated Xtext switch API to dynamically create GEF4 Graph graphs from the DOT abstract syntax tree (represented as an EMF model).

DotExport

DotExport can be used to serialize a GEF4 Graph-model, which uses the properties defined in DotProperties to a Graphviz DOT as follows:

/* Create a directed graph, making use of DotProperties */
Graph.Builder graph = new Graph.Builder();
Node node1 = new Node.Builder().attr(DotProperties.NODE_ID, "1").attr(DotProperties.NODE_LABEL, "Node 1").build();
Node node2 = new Node.Builder().attr(DotProperties.NODE_ID, "2").attr(DotProperties.NODE_LABEL, "Node 2").build();
Edge edge = new Edge.Builder(node1, node2).attr(DotProperties.EDGE_LABEL, "A dotted edge").attr(DotProperties.EDGE_STYLE, DotProperties.EDGE_STYLE_DOTTED).build();
graph.attr(DotProperties.GRAPH_TYPE, DotProperties.GRAPH_TYPE_DIRECTED.nodes(node1, node2).edges(edge);
 
/* Export the graph to a DOT string (or a DOT file) */
DotExport dotExport = new DotExport(graph.build());
System.out.println(dotExport.toDotString());

Internally, DotExport is based on JET to keep its runtime dependencies minimal.

DotProperties

DotProperties defines the (currently) supported Graphviz attributes.

DOT.UI

• feature: org.eclipse.gef4.dot.ui
• bundle: org.eclipse.gef4.dot.ui

The DOT.UI module of GEF4 DOT realizes the DOT editor as well as the DOT Graph viewer as end-user features. It does not provide any public API.