org.jscience.computing.graph.graphs
Class AbstractGraph

java.lang.Object
  extended by org.jscience.computing.graph.graphs.AbstractGraph
All Implemented Interfaces:
Graph
Direct Known Subclasses:
AbstractBaseGraph, GraphDelegator, Subgraph

public abstract class AbstractGraph
extends java.lang.Object
implements Graph

A skeletal implementation of the Graph interface, to minimize the effort required to implement graph interfaces. This implementation is applicable to both: directed graphs and undirected graphs.

See Also:
Graph, DirectedGraph, UndirectedGraph

Constructor Summary
AbstractGraph()
          Construct a new empty graph object.
 
Method Summary
 boolean addAllEdges(java.util.Collection edges)
          Adds all of the specified edges to this graph.
 boolean addAllVertices(java.util.Collection vertices)
          Adds all of the specified vertices to this graph.
protected  boolean assertVertexExist(java.lang.Object v)
          Ensures that the specified vertex exists in this graph, or else throws exception.
 boolean containsEdge(java.lang.Object sourceVertex, java.lang.Object targetVertex)
          Returns true if and only if this graph contains an edge going from the source vertex to the target vertex.
 boolean removeAllEdges(java.util.Collection edges)
          Removes all the edges in this graph that are also contained in the specified edge collection.
protected  boolean removeAllEdges(Edge[] edges)
          Removes all the edges in this graph that are also contained in the specified edge array.
 java.util.List removeAllEdges(java.lang.Object sourceVertex, java.lang.Object targetVertex)
          Removes all the edges going from the specified source vertex to the specified target vertex, and returns a list of all removed edges.
 boolean removeAllVertices(java.util.Collection vertices)
          Removes all the vertices in this graph that are also contained in the specified vertex collection.
 java.lang.String toString()
          Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph.
protected  java.lang.String toStringFromSets(java.util.Collection vertexSet, java.util.Collection edgeSet)
          Helper for subclass implementations of toString( ).
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.jscience.computing.graph.Graph
addEdge, addEdge, addVertex, containsEdge, containsVertex, edgeSet, edgesOf, getAllEdges, getEdge, getEdgeFactory, removeEdge, removeEdge, removeVertex, vertexSet
 

Constructor Detail

AbstractGraph

public AbstractGraph()
Construct a new empty graph object.

Method Detail

addAllEdges

public boolean addAllEdges(java.util.Collection edges)
Description copied from interface: Graph
Adds all of the specified edges to this graph. The behavior of this operation is undefined if the specified vertex collection is modified while the operation is in progress. This method will invoke the Graph.addEdge(Edge) method.

Specified by:
addAllEdges in interface Graph
Parameters:
edges - the edges to be added to this graph.
Returns:
true if this graph changed as a result of the call
See Also:
Graph.addAllEdges(Collection)

addAllVertices

public boolean addAllVertices(java.util.Collection vertices)
Description copied from interface: Graph
Adds all of the specified vertices to this graph. The behavior of this operation is undefined if the specified vertex collection is modified while the operation is in progress. This method will invoke the Graph.addVertex(Object) method.

Specified by:
addAllVertices in interface Graph
Parameters:
vertices - the vertices to be added to this graph.
Returns:
true if this graph changed as a result of the call
See Also:
Graph.addAllVertices(Collection)

containsEdge

public boolean containsEdge(java.lang.Object sourceVertex,
                            java.lang.Object targetVertex)
Description copied from interface: Graph
Returns true if and only if this graph contains an edge going from the source vertex to the target vertex. In undirected graphs the same result is obtained when source and target are inverted. If any of the specified vertices does not exist in the graph, or if is null, returns false.

Specified by:
containsEdge in interface Graph
Parameters:
sourceVertex - source vertex of the edge.
targetVertex - target vertex of the edge.
Returns:
true if this graph contains the specified edge.
See Also:
Graph.containsEdge(Object,Object)

removeAllEdges

public boolean removeAllEdges(java.util.Collection edges)
Description copied from interface: Graph
Removes all the edges in this graph that are also contained in the specified edge collection. After this call returns, this graph will contain no edges in common with the specified edges. This method will invoke the Graph.removeEdge(Edge) method.

Specified by:
removeAllEdges in interface Graph
Parameters:
edges - edges to be removed from this graph.
Returns:
true if this graph changed as a result of the call
See Also:
Graph.removeAllEdges(Collection)

removeAllEdges

public java.util.List removeAllEdges(java.lang.Object sourceVertex,
                                     java.lang.Object targetVertex)
Description copied from interface: Graph
Removes all the edges going from the specified source vertex to the specified target vertex, and returns a list of all removed edges. Returns null if any of the specified vertices does exist in the graph. If both vertices exist but no edge found, returns an empty list. This method will either invoke the Graph.removeEdge(Edge) method, or the Graph.removeEdge(Object,Object) method.

Specified by:
removeAllEdges in interface Graph
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.removeAllEdges(Object,Object)

removeAllVertices

public boolean removeAllVertices(java.util.Collection vertices)
Description copied from interface: Graph
Removes all the vertices in this graph that are also contained in the specified vertex collection. After this call returns, this graph will contain no vertices in common with the specified vertices. This method will invoke the Graph.removeVertex(Object) method.

Specified by:
removeAllVertices in interface Graph
Parameters:
vertices - vertices to be removed from this graph.
Returns:
true if this graph changed as a result of the call
See Also:
Graph.removeAllVertices(Collection)

toString

public java.lang.String toString()
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 java.lang.Object
Returns:
a string representation of this graph.

assertVertexExist

protected boolean assertVertexExist(java.lang.Object v)
Ensures that the specified vertex exists in this graph, or else throws exception.

Parameters:
v - vertex
Returns:
true if this assertion holds.
Throws:
java.lang.NullPointerException - if specified vertex is null.
java.lang.IllegalArgumentException - if specified vertex does not exist in this graph.

removeAllEdges

protected boolean removeAllEdges(Edge[] edges)
Removes all the edges in this graph that are also contained in the specified edge array. After this call returns, this graph will contain no edges in common with the specified edges. This method will invoke the Graph.removeEdge(Edge) method.

Parameters:
edges - edges to be removed from this graph.
Returns:
true if this graph changed as a result of the call.
See Also:
Graph.removeEdge(Edge), Graph.containsEdge(Edge)

toStringFromSets

protected java.lang.String toStringFromSets(java.util.Collection vertexSet,
                                            java.util.Collection edgeSet)
Helper for subclass implementations of toString( ).

Parameters:
vertexSet - the vertex set V to be printed
edgeSet - the edge set E to be printed
Returns:
a string representation of (V,E)