Visible and invisible hyperedge connectors

In contrast to IlvLinkConnector, the class IlvHyperEdgeConnector is a subclass of IlvGraphic and can display the contact points in the hypergraph. For example, it is useful to display the pins of a pin connector permanently at the nodes that represent electrical circuits in a signal diagram.
Not all subclasses of IlvHyperEdgeConnector use this facility. Like IlvGraphic , some connector classes need to display visible parts. Like IlvLinkConnector , other connector classes are only a logical computation facility for the contact points. Thus, the class IlvHyperEdgeConnector is a mix of a graphic object and a connection calculation algorithm.
Visible hyperedge connectors need to implement the method isGraphic to return true. They also need to implement all the usual methods of IlvGraphic , namely draw, boundingBox, and contains.
Invisible hyperedge connectors need to implement the method isGraphic() to return false. They do not need to implement the usual methods of IlvGraphic , because when isGraphic() returns false these connectors will not be used as graphic objects.
Visible hyperedge connectors can only be attached to nodes, not to hyperedges. The position of a visible hyperedge connector is always the same position as the node. When the node is moved, the hyperedge connector is automatically moved with the node. When the node is removed or inserted into a different hypergraph, the hyperedge connector is automatically removed and inserted into the same hypergraph as the node; that is, you need only to attach the connector to the node and the entire handling of the hyperedge connector as a graphic object is done automatically.
The only predefined visible hyperedge connector is IlvHyperEdgePinConnector. All other predefined hyperedge connectors are invisible connectors. See IlvHyperEdgeConnector for additional information.