Difference between revisions of "GEF/GEF4/DOT"

/* We can create Graphs based on Graphviz Dot files and strings */
DotImport dotImport = new DotImport();
Graph graph = dotImport.importDot("graph { 1--2 ; 1--3 }");
Graph digraph = dotImport.importDot("digraph { 1->2 ; 1->3 }");

/* Set up a directed graph with a single connection: */
Graph graph = new Graph.Builder()
.attr(DotAttributes._TYPE__G, DotAttributes._TYPE__G__GRAPH)
.node("n1")
.attr(DotAttributes._NAME__GNE, "1")
.attr(DotAttributes.LABEL__GNE, "Node 1")
.node("n2")
.attr(DotAttributes._NAME__GNE, "2")
.attr(DotAttributes.LABEL__GNE, "Node 2")
.edge("n1", "n2")
.attr(DotAttributes.LABEL__GNE, "A dotted edge")
.attr(DotAttributes.STYLE__GNE, EdgeStyle.DOTTED.toString())
.build();
 
/* Export the graph to a DOT string or a DOT file: */
System.out.println(new DotExport().exportDot(graph));

@Override
public void applyLayout(boolean clean) {
  // convert a Graph with LayoutAttributes (input model to ILayoutAlgorithm) into one with DotAttributes, which can be
  // exported to a DOT string; keep track of converted nodes (as a side-effect)
  final Map<Node, String> nodesToNameMap = new HashMap<>();
  IAttributeCopier layout2DotAttributesConverter = new IAttributeCopier() {
    int nodeIndex = 0;
 
    @Override
    public void copy(IAttributeStore source, IAttributeStore target) {
      if (source instanceof Node && target instanceof Node) {
        // convert LayoutProperties#location to DotAttributes#pos (both refer to center locations)
        Point location = LayoutProperties.getLocation((Node) source);
        org.eclipse.gef4.dot.internal.parser.point.Point posParsed = PointFactory.eINSTANCE.createPoint();
        posParsed.setX(location.x);
        posParsed.setY(location.y);
        DotAttributes.setPosParsed((Node) target, posParsed);
        // provide unique names and keep track of the mapped nodes
        DotAttributes._setName((Node) target, Integer.toString(++nodeIndex));
        nodesToNameMap.put((Node) source, DotAttributes._getName((Node) target));
      }
    }			
  };			 
  Graph dotGraph = new GraphCopier(layout2DotAttributesConverter).copy(context.getGraph());
 
  // set graph type
  DotAttributes._setType(dotGraph, DotAttributes._TYPE__G__DIGRAPH);
 
  // specify layout algorithm
  DotAttributes.setLayout(dotGraph, Layout.CIRCO.toString());
 
  // export the dot string and call the dot executable to add layout info to it.
  DotExport dotExport = new DotExport();
  String dot = dotExport.exportDot(dotGraph);
  File tmpFile = DotFileUtils.write(dot);
  String[] dotResult = DotExecutableUtils.executeDot(new File(dotExecutablePath), true, tmpFile, null, null);
  if (!dotResult[1].isEmpty()) {
    System.err.println(dotResult[1]);
  }
  tmpFile.delete();
  Graph layoutedDotGraph = new DotImport().importDot(dotResult[0]);
 
  // transfer the DOT provided position information back to the input Graph
  for (Node target : context.getGraph().getNodes()) {
    String nodeName = nodesToNameMap.get(target);
    for (Node source : layoutedDotGraph.getNodes()) {
      if (nodeName.equals(DotAttributes._getName(source))) {
        // convert back DotAttributes#pos to LayoutProperties#location
        org.eclipse.gef4.dot.internal.parser.point.Point posParsed = DotAttributes.getPosParsed(source);
        LayoutProperties.setLocation(target, new Point(posParsed.getX(), posParsed.getY()));
	break;
      }
    }
  }
}