salvo.jesus.graph.listener

Class DirectedAcyclicGraphListener

java.lang.Object

salvo.jesus.graph.listener.NullGraphListener

salvo.jesus.graph.listener.DirectedAcyclicGraphListener

All Implemented Interfaces:

Serializable, EventListener, GraphListener

public class DirectedAcyclicGraphListener
extends NullGraphListener

DirectedAcyclicGraphListener enforces the DAG property of a graph. It can be used as a delegate by any class which wants to implement the DirectedAcyclicGraph interface.

Version:

$Id: DirectedAcyclicGraphListener.java,v 1.2 2002/03/12 07:48:34 perfecthash Exp $

Author:

John V. Sichi

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DirectedAcyclicGraphListener(DirectedAcyclicGraph graph) Creates a new DirectedAcyclicGraphListener for the given graph.

Method Summary

Modifier and Type	Method and Description
void	beforeEdgeAdded(GraphAddEdgeEvent event) Called when an edge is being added to a graph, just before the graph structure is actually changed.
List	getRoot() Implementation for DirectedAcyclicGraph.getRoot().

Methods inherited from class salvo.jesus.graph.listener.NullGraphListener

afterEdgeAdded, afterEdgeRemoved, afterVertexAdded, afterVertexRemoved, beforeEdgeRemoved, beforeVertexAdded, beforeVertexRemoved

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DirectedAcyclicGraphListener

public DirectedAcyclicGraphListener(DirectedAcyclicGraph graph)

Creates a new DirectedAcyclicGraphListener for the given graph.

Parameters:

graph - the graph to which this listener is to be attached; this constructor will automatically register the listener to receive all events

Method Detail

beforeEdgeAdded

public void beforeEdgeAdded(GraphAddEdgeEvent event)
                     throws Exception

Description copied from interface: GraphListener

Called when an edge is being added to a graph, just before the graph structure is actually changed.

Specified by:

beforeEdgeAdded in interface GraphListener

Overrides:

beforeEdgeAdded in class NullGraphListener

Parameters:

event - the event describing the edge addition

Throws:

Exception

getRoot

public List getRoot()

Implementation for DirectedAcyclicGraph.getRoot().