public SWTJGraphPane(Composite theParent, Graph graph, GroupLegendItem theLegendRoot) {
super(theParent, SWT.NO_BACKGROUND);
this.parent = theParent;
m_legend = new Legend(theLegendRoot, true);
m_graphListner = new GraphHandler();
m_lensListener = new LensHandler();
m_nodePositions = new HashMap <Node, JPowerGraphPoint>();
m_manipulators = new ArrayList <Manipulator> ();
m_manipulatorsByName = new HashMap <String, Manipulator> ();