/* ==========================================
* JGraphT : a free Java graph-theory library
* ==========================================
*
* Project Info: http://jgrapht.sourceforge.net/
* Project Creator: Barak Naveh (http://sourceforge.net/users/barak_naveh)
*
* (C) Copyright 2003-2009, by Barak Naveh and Contributors.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
/* -------------------------
* GraphUnion.java
* -------------------------
* (C) Copyright 2009-2009, by Ilya Razenshteyn
*
* Original Author: Ilya Razenshteyn and Contributors.
*
* $Id: GraphUnion.java 695 2009-07-06 02:18:35Z perfecthash $
*
* Changes
* -------
* 02-Feb-2009 : Initial revision (IR);
*
*/
package edu.nd.nina.graph;
import java.io.*;
import java.util.*;
import edu.nd.nina.*;
import edu.nd.nina.util.*;
/**
* <p>Read-only union of two graphs: G<sub>1</sub> and G<sub>2</sub>. If
* G<sub>1</sub> = (V<sub>1</sub>, E<sub>1</sub>) and G<sub>2</sub> =
* (V<sub>2</sub>, E<sub>2</sub>) then their union G = (V, E), where V is the
* union of V<sub>1</sub> and V<sub>2</sub>, and E is the union of E<sub>1</sub>
* and E<sub>1</sub>.</p>
*
* <p><tt>GraphUnion</tt> implements <tt>Graph</tt> interface. <tt>
* GraphUnion</tt> uses <tt>WeightCombiner</tt> to choose policy for calculating
* edge weight.</p>
*/
public class GraphUnion<V, E, G extends Graph<V, E>>
extends AbstractGraph<V, E>
implements Serializable
{
//~ Static fields/initializers ---------------------------------------------
private static final long serialVersionUID = -740199233080172450L;
private static final String READ_ONLY = "union of graphs is read-only";
//~ Instance fields --------------------------------------------------------
private G g1;
private G g2;
private WeightCombiner operator;
//~ Constructors -----------------------------------------------------------
public GraphUnion(G g1, G g2, WeightCombiner operator)
{
if (g1 == null) {
throw new NullPointerException("g1 is null");
}
if (g2 == null) {
throw new NullPointerException("g2 is null");
}
if (g1 == g2) {
throw new IllegalArgumentException("g1 is equal to g2");
}
this.g1 = g1;
this.g2 = g2;
this.operator = operator;
}
public GraphUnion(G g1, G g2)
{
this(g1, g2, WeightCombiner.SUM);
}
//~ Methods ----------------------------------------------------------------
public Set<E> getAllEdges(V sourceVertex, V targetVertex)
{
Set<E> res = new HashSet<E>();
if (g1.containsVertex(sourceVertex)
&& g1.containsVertex(targetVertex))
{
res.addAll(g1.getAllEdges(sourceVertex, targetVertex));
}
if (g2.containsVertex(sourceVertex)
&& g2.containsVertex(targetVertex))
{
res.addAll(g2.getAllEdges(sourceVertex, targetVertex));
}
return Collections.unmodifiableSet(res);
}
public E getEdge(V sourceVertex, V targetVertex)
{
E res = null;
if (g1.containsVertex(sourceVertex)
&& g1.containsVertex(targetVertex))
{
res = g1.getEdge(sourceVertex, targetVertex);
}
if ((res == null)
&& g2.containsVertex(sourceVertex)
&& g2.containsVertex(targetVertex))
{
res = g2.getEdge(sourceVertex, targetVertex);
}
return res;
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public EdgeFactory<V, E> getEdgeFactory()
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public E addEdge(V sourceVertex, V targetVertex)
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public boolean addEdge(V sourceVertex, V targetVertex, E e)
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public boolean addVertex(V v)
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* @see Graph#getAllMatchingType(Class<?>)
*/
public Set<V> getAllMatchingType(Class<?> clazz) {
Set<V> res = new HashSet<V>();
res.addAll(g1.getAllMatchingType(clazz));
res.addAll(g2.getAllMatchingType(clazz));
return Collections.unmodifiableSet(res);
}
/**
* @see Graph#getTypes()
*/
public Set<Class<?>> getTypes() {
Set<Class<?>> res = new HashSet<Class<?>>();
res.addAll(g1.getTypes());
res.addAll(g2.getTypes());
return Collections.unmodifiableSet(res);
}
public boolean containsEdge(E e)
{
return g1.containsEdge(e) || g2.containsEdge(e);
}
public boolean containsVertex(V v)
{
return g1.containsVertex(v) || g2.containsVertex(v);
}
public Set<E> edgeSet()
{
Set<E> res = new HashSet<E>();
res.addAll(g1.edgeSet());
res.addAll(g2.edgeSet());
return Collections.unmodifiableSet(res);
}
public Set<E> edgesOf(V vertex)
{
Set<E> res = new HashSet<E>();
if (g1.containsVertex(vertex)) {
res.addAll(g1.edgesOf(vertex));
}
if (g2.containsVertex(vertex)) {
res.addAll(g2.edgesOf(vertex));
}
return Collections.unmodifiableSet(res);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public E removeEdge(V sourceVertex, V targetVertex)
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public boolean removeEdge(E e)
{
throw new UnsupportedOperationException(READ_ONLY);
}
/**
* Throws <tt>UnsupportedOperationException</tt>, because <tt>
* GraphUnion</tt> is read-only.
*/
public boolean removeVertex(V v)
{
throw new UnsupportedOperationException(READ_ONLY);
}
public Set<V> vertexSet()
{
Set<V> res = new HashSet<V>();
res.addAll(g1.vertexSet());
res.addAll(g2.vertexSet());
return Collections.unmodifiableSet(res);
}
public V getEdgeSource(E e)
{
if (g1.containsEdge(e)) {
return g1.getEdgeSource(e);
}
if (g2.containsEdge(e)) {
return g2.getEdgeSource(e);
}
return null;
}
public V getEdgeTarget(E e)
{
if (g1.containsEdge(e)) {
return g1.getEdgeTarget(e);
}
if (g2.containsEdge(e)) {
return g2.getEdgeTarget(e);
}
return null;
}
public double getEdgeWeight(E e)
{
if (g1.containsEdge(e) && g2.containsEdge(e)) {
return operator.combine(g1.getEdgeWeight(e), g2.getEdgeWeight(e));
}
if (g1.containsEdge(e)) {
return g1.getEdgeWeight(e);
}
if (g2.containsEdge(e)) {
return g2.getEdgeWeight(e);
}
throw new IllegalArgumentException("no such edge in the union");
}
/**
* @return G<sub>1</sub>
*/
public G getG1()
{
return g1;
}
/**
* @return G<sub>2</sub>
*/
public G getG2()
{
return g2;
}
}
// End GraphUnion.java