org.jgrapht.graph

Class GraphDelegator<V,E>

java.lang.Object

org.jgrapht.graph.AbstractGraph<V,E>

org.jgrapht.graph.GraphDelegator<V,E>

All Implemented Interfaces:

Serializable, Graph<V,E>

Direct Known Subclasses:

AsUndirectedGraph, AsUnweightedDirectedGraph, AsUnweightedGraph, AsWeightedGraph, DefaultListenableGraph, EdgeReversedGraph, ParanoidGraph, UnmodifiableGraph

public class GraphDelegator<V,E>
extends AbstractGraph<V,E>
implements Graph<V,E>, Serializable

A graph backed by the the graph specified at the constructor, which delegates all its methods to the backing graph. Operations on this graph "pass through" to the to the backing graph. Any modification made to this graph or the backing graph is reflected by the other.

This graph does not pass the hashCode and equals operations through to the backing graph, but relies on Object's equals and hashCode methods.

This class is mostly used as a base for extending subclasses.

Since:

Jul 20, 2003

Author:

Barak Naveh

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
GraphDelegator(Graph<V,E> g) Constructor for GraphDelegator.

Method Summary

Methods

Modifier and Type	Method and Description
E	addEdge(V sourceVertex, V targetVertex) Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.
boolean	addEdge(V sourceVertex, V targetVertex, E e) Adds the specified edge to this graph, going from the source vertex to the target vertex.
boolean	addVertex(V v) Adds the specified vertex to this graph if not already present.
boolean	containsEdge(E e) Returns true if this graph contains the specified edge.
boolean	containsVertex(V v) Returns true if this graph contains the specified vertex.
int	degreeOf(V vertex)
Set<E>	edgeSet() Returns a set of the edges contained in this graph.
Set<E>	edgesOf(V vertex) Returns a set of all edges touching the specified vertex.
Set<E>	getAllEdges(V sourceVertex, V targetVertex) Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph.
E	getEdge(V sourceVertex, V targetVertex) Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph.
EdgeFactory<V,E>	getEdgeFactory() Returns the edge factory using which this graph creates new edges.
V	getEdgeSource(E e) Returns the source vertex of an edge.
V	getEdgeTarget(E e) Returns the target vertex of an edge.
double	getEdgeWeight(E e) Returns the weight assigned to a given edge.
Set<E>	incomingEdgesOf(V vertex)
int	inDegreeOf(V vertex)
int	outDegreeOf(V vertex)
Set<E>	outgoingEdgesOf(V vertex)
boolean	removeEdge(E e) Removes the specified edge from the graph.
E	removeEdge(V sourceVertex, V targetVertex) Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph.
boolean	removeVertex(V v) Removes the specified vertex from this graph including all its touching edges if present.
void	setEdgeWeight(E e, double weight)
String	toString() Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph.
Set<V>	vertexSet() Returns a set of the vertices contained in this graph.

Methods inherited from class org.jgrapht.graph.AbstractGraph

assertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, removeAllVertices, toStringFromSets

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.jgrapht.Graph

containsEdge, removeAllEdges, removeAllEdges, removeAllVertices

Constructor Detail

GraphDelegator

public GraphDelegator(Graph<V,E> g)

Constructor for GraphDelegator.

Parameters:

g - the backing graph (the delegate).

Throws:

IllegalArgumentException - iff g==null

Method Detail

getAllEdges

public Set<E> getAllEdges(V sourceVertex,
                 V targetVertex)

Description copied from interface: Graph

Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph. If any of the vertices does not exist or is null, returns null. If both vertices exist but no edges found, returns an empty set.

In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.

Specified by:

getAllEdges in interface Graph<V,E>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

a set of all edges connecting source vertex to target vertex.

See Also:

Graph.getAllEdges(Object, Object)

getEdge

public E getEdge(V sourceVertex,
        V targetVertex)

Description copied from interface: Graph

Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph. Otherwise returns null. If any of the specified vertices is null returns null

In undirected graphs, the returned edge may have its source and target vertices in the opposite order.

Specified by:

getEdge in interface Graph<V,E>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

an edge connecting source vertex to target vertex.

See Also:

Graph.getEdge(Object, Object)

getEdgeFactory

public EdgeFactory<V,E> getEdgeFactory()

Description copied from interface: Graph

Returns the edge factory using which this graph creates new edges. The edge factory is defined when the graph is constructed and must not be modified.

Specified by:

getEdgeFactory in interface Graph<V,E>

Returns:

the edge factory using which this graph creates new edges.

See Also:

Graph.getEdgeFactory()

addEdge

public E addEdge(V sourceVertex,
        V targetVertex)

Description copied from interface: Graph

Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, than this method does not change the graph and returns null.

The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

This method creates the new edge e using this graph's EdgeFactory. For the new edge to be added e must not be equal to any other edge the graph (even if the graph allows edge-multiplicity). More formally, the graph must not contain any edge e2 such that e2.equals(e). If such e2 is found then the newly created edge e is abandoned, the method leaves this graph unchanged returns null.

Specified by:

addEdge in interface Graph<V,E>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

The newly created edge if added to the graph, otherwise null.

See Also:

Graph.addEdge(Object, Object)

addEdge

public boolean addEdge(V sourceVertex,
              V targetVertex,
              E e)

Description copied from interface: Graph

Adds the specified edge to this graph, going from the source vertex to the target vertex. More formally, adds the specified edge, e, to this graph if this graph contains no edge e2 such that e2.equals(e). If this graph already contains such an edge, the call leaves this graph unchanged and returns false. Some graphs do not allow edge-multiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, than this method does not change the graph and returns false. If the edge was added to the graph, returns true.

The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.

Specified by:

addEdge in interface Graph<V,E>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

e - edge to be added to this graph.

Returns:

true if this graph did not already contain the specified edge.

See Also:

Graph.addEdge(Object, Object, Object)

addVertex

public boolean addVertex(V v)

Description copied from interface: Graph

Adds the specified vertex to this graph if not already present. More formally, adds the specified vertex, v, to this graph if this graph contains no vertex u such that u.equals(v). If this graph already contains such vertex, the call leaves this graph unchanged and returns false. In combination with the restriction on constructors, this ensures that graphs never contain duplicate vertices.

Specified by:

addVertex in interface Graph<V,E>

Parameters:

v - vertex to be added to this graph.

Returns:

true if this graph did not already contain the specified vertex.

See Also:

Graph.addVertex(Object)

containsEdge

public boolean containsEdge(E e)

Description copied from interface: Graph

Returns true if this graph contains the specified edge. More formally, returns true if and only if this graph contains an edge e2 such that e.equals(e2). If the specified edge is null returns false.

Specified by:

containsEdge in interface Graph<V,E>

Parameters:

e - edge whose presence in this graph is to be tested.

Returns:

true if this graph contains the specified edge.

See Also:

Graph.containsEdge(Object)

containsVertex

public boolean containsVertex(V v)

Description copied from interface: Graph

Returns true if this graph contains the specified vertex. More formally, returns true if and only if this graph contains a vertex u such that u.equals(v). If the specified vertex is null returns false.

Specified by:

containsVertex in interface Graph<V,E>

Parameters:

v - vertex whose presence in this graph is to be tested.

Returns:

true if this graph contains the specified vertex.

See Also:

Graph.containsVertex(Object)

degreeOf

public int degreeOf(V vertex)

See Also:

UndirectedGraph.degreeOf(Object)

edgeSet

public Set<E> edgeSet()

Description copied from interface: Graph

Returns a set of the edges contained in this graph. The set is backed by the graph, so changes to the graph are reflected in the set. If the graph is modified while an iteration over the set is in progress, the results of the iteration are undefined.

The graph implementation may maintain a particular set ordering (e.g. via LinkedHashSet) for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.

Specified by:

edgeSet in interface Graph<V,E>

Returns:

a set of the edges contained in this graph.

See Also:

Graph.edgeSet()

edgesOf

public Set<E> edgesOf(V vertex)

Description copied from interface: Graph

Returns a set of all edges touching the specified vertex. If no edges are touching the specified vertex returns an empty set.

Specified by:

edgesOf in interface Graph<V,E>

Parameters:

vertex - the vertex for which a set of touching edges is to be returned.

Returns:

a set of all edges touching the specified vertex.

See Also:

Graph.edgesOf(Object)

inDegreeOf

public int inDegreeOf(V vertex)

See Also:

DirectedGraph.inDegreeOf(Object)

incomingEdgesOf

public Set<E> incomingEdgesOf(V vertex)

See Also:

DirectedGraph.incomingEdgesOf(Object)

outDegreeOf

public int outDegreeOf(V vertex)

See Also:

DirectedGraph.outDegreeOf(Object)

outgoingEdgesOf

public Set<E> outgoingEdgesOf(V vertex)

See Also:

DirectedGraph.outgoingEdgesOf(Object)

removeEdge

public boolean removeEdge(E e)

Description copied from interface: Graph

Removes the specified edge from the graph. Removes the specified edge from this graph if it is present. More formally, removes an edge e2 such that e2.equals(e), if the graph contains such edge. Returns true if the graph contained the specified edge. (The graph will not contain the specified edge once the call returns).

If the specified edge is null returns false.

Specified by:

removeEdge in interface Graph<V,E>

Parameters:

e - edge to be removed from this graph, if present.

Returns:

true if and only if the graph contained the specified edge.

See Also:

Graph.removeEdge(Object)

removeEdge

public E removeEdge(V sourceVertex,
           V targetVertex)

Description copied from interface: Graph

Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph. Returns the edge if removed or null otherwise.

Specified by:

removeEdge in interface Graph<V,E>

Parameters:

sourceVertex - source vertex of the edge.

targetVertex - target vertex of the edge.

Returns:

The removed edge, or null if no edge removed.

See Also:

Graph.removeEdge(Object, Object)

removeVertex

public boolean removeVertex(V v)

Description copied from interface: Graph

Removes the specified vertex from this graph including all its touching edges if present. More formally, if the graph contains a vertex u such that u.equals(v), the call removes all edges that touch u and then removes u itself. If no such u is found, the call leaves the graph unchanged. Returns true if the graph contained the specified vertex. (The graph will not contain the specified vertex once the call returns).

If the specified vertex is null returns false.

Specified by:

removeVertex in interface Graph<V,E>

Parameters:

v - vertex to be removed from this graph, if present.

Returns:

true if the graph contained the specified vertex; false otherwise.

See Also:

Graph.removeVertex(Object)

toString

public String toString()

Description copied from class: AbstractGraph

Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph. 'V' is the string representation of the vertex set, and 'E' is the string representation of the edge set.

Overrides:

toString in class AbstractGraph<V,E>

Returns:

a string representation of this graph.

See Also:

Object.toString()

vertexSet

public Set<V> vertexSet()

Description copied from interface: Graph

Returns a set of the vertices contained in this graph. The set is backed by the graph, so changes to the graph are reflected in the set. If the graph is modified while an iteration over the set is in progress, the results of the iteration are undefined.

The graph implementation may maintain a particular set ordering (e.g. via LinkedHashSet) for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.

Specified by:

vertexSet in interface Graph<V,E>

Returns:

a set view of the vertices contained in this graph.

See Also:

Graph.vertexSet()

getEdgeSource

public V getEdgeSource(E e)

Description copied from interface: Graph

Returns the source vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning).

Specified by:

getEdgeSource in interface Graph<V,E>

Parameters:

e - edge of interest

Returns:

source vertex

See Also:

Graph.getEdgeSource(Object)

getEdgeTarget

public V getEdgeTarget(E e)

Description copied from interface: Graph

Returns the target vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning).

Specified by:

getEdgeTarget in interface Graph<V,E>

Parameters:

e - edge of interest

Returns:

target vertex

See Also:

Graph.getEdgeTarget(Object)

getEdgeWeight

public double getEdgeWeight(E e)

Description copied from interface: Graph

Returns the weight assigned to a given edge. Unweighted graphs return 1.0 (as defined by WeightedGraph.DEFAULT_EDGE_WEIGHT), allowing weighted-graph algorithms to apply to them where meaningful.

Specified by:

getEdgeWeight in interface Graph<V,E>

Parameters:

e - edge of interest

Returns:

edge weight

See Also:

Graph.getEdgeWeight(Object)

setEdgeWeight

public void setEdgeWeight(E e,
                 double weight)

See Also:

WeightedGraph.setEdgeWeight(Object, double)