com.phoenixst.plexus.examples
Class EmptyGraph

java.lang.Object
  com.phoenixst.plexus.AbstractGraph
      com.phoenixst.plexus.examples.AbstractIntegerNodeGraph
          com.phoenixst.plexus.examples.EmptyGraph

All Implemented Interfaces:

Graph, Serializable

public class EmptyGraph
extends AbstractIntegerNodeGraph

A Graph containing a set of Integer nodes and no edges.

Since:

1.0

Version:

$Revision: 1.25 $

Author:

Ray A. Conner

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.phoenixst.plexus.examples.AbstractIntegerNodeGraph

AbstractIntegerNodeGraph.AbstractIntegerEdgeCollection, AbstractIntegerNodeGraph.EdgeImpl

Nested classes/interfaces inherited from interface com.phoenixst.plexus.Graph

Graph.Edge

Constructor Summary

EmptyGraph(int n)
Creates a new EmptyGraph.

Method Summary

Collection	adjacentNodes(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns an empty Collection.
boolean	containsEdge(Graph.Edge edge) Returns false.
protected Graph.Edge	createEdge(int tailIndex, int headIndex) If an edge exists between the specified indices, create and return it.
protected Collection	createEdgeCollection() Creates the (single) collection of edges for this instance.
protected Traverser	createTraverser(int nodeIndex) Creates a traverser with no filtering; assumes that the node index is valid.
int	degree(Object node) Returns 0.
int	degree(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns 0.
Collection	edges(org.apache.commons.collections.Predicate edgePredicate) Returns an empty Collection.
Object	getAdjacentNode(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns null.
Graph.Edge	getEdge(org.apache.commons.collections.Predicate edgePredicate) Returns null.
Graph.Edge	getIncidentEdge(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns null.
Collection	incidentEdges(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns an empty Collection.
String	toString()
Traverser	traverser(Object node, org.apache.commons.collections.Predicate traverserPredicate) Returns an empty Traverser.

Methods inherited from class com.phoenixst.plexus.examples.AbstractIntegerNodeGraph

checkNode, containsNode, edges, getNodeIndex, getNodeSize, nodes, removeEdge, removeNode, traverser

Methods inherited from class com.phoenixst.plexus.AbstractGraph

addEdge, addNode, getNode, nodes

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyGraph

public EmptyGraph(int n)

Creates a new EmptyGraph.

Method Detail

containsEdge

public boolean containsEdge(Graph.Edge edge)

Returns false.

Specified by:

containsEdge in interface Graph

Overrides:

containsEdge in class AbstractIntegerNodeGraph

Parameters:

edge - the Graph.Edge whose presence in this Graph is to be tested.

Returns:

true if this Graph contains the specified Graph.Edge.

degree

public int degree(Object node)

Returns 0.

Specified by:

degree in interface Graph

Overrides:

degree in class AbstractGraph

Parameters:

node - return the degree of this node.

Returns:

the degree of node.

degree

public int degree(Object node,
                  org.apache.commons.collections.Predicate traverserPredicate)

Returns 0.

Specified by:

degree in interface Graph

Overrides:

degree in class AbstractGraph

Parameters:

node - return the degree of this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the counted Graph.Edges must satisfy.

Returns:

the degree of node for which the specified predicate is satisfied.

edges

public Collection edges(org.apache.commons.collections.Predicate edgePredicate)

Returns an empty Collection.

Specified by:

edges in interface Graph

Overrides:

edges in class AbstractGraph

Parameters:

edgePredicate - the predicate which the returned Graph.Edges must satisfy.

Returns:

the Graph.Edges from this Graph that satisfy the specified predicate.

adjacentNodes

public Collection adjacentNodes(Object node,
                                org.apache.commons.collections.Predicate traverserPredicate)

Returns an empty Collection.

Specified by:

adjacentNodes in interface Graph

Overrides:

adjacentNodes in class AbstractGraph

Parameters:

node - return the nodes adjacent to this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the returned nodes and the traversed Graph.Edges must satisfy.

Returns:

the nodes adjacent to the specified node for which the specified predicate is satisfied.

incidentEdges

public Collection incidentEdges(Object node,
                                org.apache.commons.collections.Predicate traverserPredicate)

Returns an empty Collection.

Specified by:

incidentEdges in interface Graph

Overrides:

incidentEdges in class AbstractGraph

Parameters:

node - return the Graph.Edges incident on this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the returned Graph.Edges must satisfy.

Returns:

the Graph.Edges incident on the specified node for which the specified predicate is satisfied.

getEdge

public Graph.Edge getEdge(org.apache.commons.collections.Predicate edgePredicate)

Returns null.

Specified by:

getEdge in interface Graph

Overrides:

getEdge in class AbstractGraph

Parameters:

edgePredicate - the predicate which the returned Graph.Edge must satisfy.

Returns:

a Graph.Edge from this Graph that satisfies the specified predicate, or null if no such Graph.Edge exists.

getAdjacentNode

public Object getAdjacentNode(Object node,
                              org.apache.commons.collections.Predicate traverserPredicate)

Returns null.

Specified by:

getAdjacentNode in interface Graph

Overrides:

getAdjacentNode in class AbstractGraph

Parameters:

node - traverse to a node adjacent to this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the returned node and the traversed Graph.Edge must satisfy.

Returns:

a node adjacent to the specified node for which the specified predicate is satisfied.

getIncidentEdge

public Graph.Edge getIncidentEdge(Object node,
                                  org.apache.commons.collections.Predicate traverserPredicate)

Returns null.

Specified by:

getIncidentEdge in interface Graph

Overrides:

getIncidentEdge in class AbstractGraph

Parameters:

node - traverse to a Graph.Edge incident on this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the returned Graph.Edge must satisfy.

Returns:

a Graph.Edge incident on the specified node for which the specified predicate is satisfied.

traverser

public Traverser traverser(Object node,
                           org.apache.commons.collections.Predicate traverserPredicate)

Returns an empty Traverser.

Specified by:

traverser in interface Graph

Overrides:

traverser in class AbstractGraph

Parameters:

node - traverse over all nodes adjacent to this node for which the specified predicate is satisfied.

traverserPredicate - the predicate which the returned nodes and their traversed Graph.Edges must satisfy.

Returns:

a Traverser from node to all adjacent nodes for which the specified predicate is satisfied.

createEdge

protected Graph.Edge createEdge(int tailIndex,
                                int headIndex)

Description copied from class: AbstractIntegerNodeGraph

If an edge exists between the specified indices, create and return it. If not, return null. The indices are assumed to represent valid nodes for this Graph.

Specified by:

createEdge in class AbstractIntegerNodeGraph

createEdgeCollection

protected Collection createEdgeCollection()

Description copied from class: AbstractIntegerNodeGraph

Creates the (single) collection of edges for this instance.

Specified by:

createEdgeCollection in class AbstractIntegerNodeGraph

createTraverser

protected Traverser createTraverser(int nodeIndex)

Description copied from class: AbstractIntegerNodeGraph

Creates a traverser with no filtering; assumes that the node index is valid.

Specified by:

createTraverser in class AbstractIntegerNodeGraph

toString

public String toString()

Overrides:

toString in class Object