_nodeCreator = new NodeCreator();
_nodeCreator.setMouseFilter(_controlFilter);
pane.getBackgroundEventLayer().addInteractor(_nodeCreator);
// Create the interactor that drags new edges.
_edgeCreator = new EdgeCreator(this) {
public Object createEdge() {
Object semanticObject = Integer.valueOf(_globalCount++);
BasicGraphModel bgm = (BasicGraphModel) getGraphModel();
return bgm.createEdge(semanticObject);
}