public class EdgeEditPart extends AbstractDiagramEdgeEditPart implements IStyleEditPart{

	public EdgeEditPart(View view) {
		super(view);
	}
	
	public DragTracker getDragTracker(Request request) {
        return getParent().getDragTracker(request);
    }
	
	@Override
	protected Connection createConnectionFigure() {
		Figure figure = new EdgePipeConnection();
		return (Connection) figure;
	}
	
}

public class TreeEditPartProvider extends AbstractEditPartProvider {

	public TreeEditPartProvider() {
		super();
	}

	@Override
	protected Class<?> getNodeEditPartClass(View view) {
		if (view.getElement() instanceof CustomStyle) {
			CustomStyle customStyle = (CustomStyle) view.getElement();
			if (customStyle.getId().equals(TreeEditPart.TREE_EDITPART_ID)) {
				return TreeEditPart.class;
			}
		}
		return super.getNodeEditPartClass(view);
	}

	@Override
	protected Class<?> getEdgeEditPartClass(View view) {
		if (view.getElement() instanceof DEdge) {
			return EdgeEditPart.class;
		}
		return super.getEdgeEditPartClass(view);
	}
}

public class EdgeEditPart extends AbstractDiagramEdgeEditPart implements IStyleEditPart{

	public EdgeEditPart(View view) {
		super(view);
	}
	
	public DragTracker getDragTracker(Request request) {
        return getParent().getDragTracker(request);
    }
	
	@Override
	protected Connection createConnectionFigure() {
		Figure figure = new EdgePipeConnection();
		return (Connection) figure;
	}
	
}

public class EdgePipeConnection extends PolylineConnectionEx {

	// offset X
	private static int OFFSET_X = 70;

	// offset Y
	private static int OFFSET_Y = 0;

	// list of precision points
	private List<PrecisionPoint> connectionPoints = new ArrayList<PrecisionPoint>();

	// bend x
	private int bend_X;
	// bend y
	private int bend_Y;

	// counter for queue entries
	private int queueEntries = 0;
...

/**
     * @was-generated
     */
    protected boolean addFixedChild(EditPart childEditPart) {
        if (childEditPart instanceof DEdgeNameEditPart) {
            ((DEdgeNameEditPart) childEditPart).setLabel(getPrimaryShape().getFigureViewEdgeNameFigure());
            return true;
        }
        if (childEditPart instanceof DEdgeEndNameEditPart) {
            ((DEdgeEndNameEditPart) childEditPart).setLabel(getPrimaryShape().getFigureViewEndEdgeNameFigure());
            return true;
        }
        if (childEditPart instanceof DEdgeBeginNameEditPart) {
            ((DEdgeBeginNameEditPart) childEditPart).setLabel(getPrimaryShape().getFigureViewBeginEdgeNameFigure());
            return true;
        }
        return false;
    }

    /**
     * @was-generated
     */
    public AbstractDiagramEdgeEditPart.ViewEdgeFigure getPrimaryShape() {
        return (AbstractDiagramEdgeEditPart.ViewEdgeFigure) getFigure();
    }

    /**
     * @was-generated
     */
    @Override
    protected void addChildVisual(EditPart childEditPart, int index) {
        if (addFixedChild(childEditPart)) {
            return;
        }
        super.addChildVisual(childEditPart, -1);
    }