private GraphicsController createEdgeController(GeometryIndex index) {
    CompositeGeometryIndexController controller =
        new CompositeGeometryIndexController(
            mapWidget,
            editingService,
            index,
            editingService.getEditingState() == GeometryEditState.DRAGGING);
    for (AbstractGeometryIndexMapHandler handler : EditingHandlerRegistry.getEdgeHandlers()) {
      controller.addMapHandler(handler);
    }
    for (EdgeMapHandlerFactory factory : customEdgeFactories) {
      controller.addMapHandler(factory.create());
    }

    EdgeMarkerHandler edgeMarkerHandler =
        new EdgeMarkerHandler(mapWidget, editingService, controller);
    controller.addMouseOutHandler(edgeMarkerHandler);
    controller.addMouseMoveHandler(edgeMarkerHandler);
    controller.addMapDownHandler(edgeMarkerHandler);
    return controller;
  }