Initial opendaylight infrastructure commit!!

[controller.git] / third-party / net.sf.jung2 / src / main / java / edu / uci / ics / jung / algorithms / transformation / DirectionTransformer.java

diff --git a/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/transformation/DirectionTransformer.java b/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/transformation/DirectionTransformer.java
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+++ b/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/transformation/DirectionTransformer.java
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+/*
+ * Copyright (c) 2003, the JUNG Project and the Regents of the University 
+ * of California
+ * All rights reserved.
+ *
+ * This software is open-source under the BSD license; see either
+ * "license.txt" or
+ * http://jung.sourceforge.net/license.txt for a description.
+ */
+/*
+ * Created on Apr 21, 2004
+ */
+package edu.uci.ics.jung.algorithms.transformation;
+
+import org.apache.commons.collections15.Factory;
+
+import edu.uci.ics.jung.graph.DirectedGraph;
+import edu.uci.ics.jung.graph.Graph;
+import edu.uci.ics.jung.graph.UndirectedGraph;
+import edu.uci.ics.jung.graph.util.EdgeType;
+import edu.uci.ics.jung.graph.util.Pair;
+
+/**
+ * <p>Functions for transforming graphs into directed or undirected graphs.</p>
+ * 
+ * 
+ * @author Danyel Fisher
+ * @author Joshua O'Madadhain
+ */
+public class DirectionTransformer 
+{
+
+    /**
+     * Transforms <code>graph</code> (which may be of any directionality)
+     * into an undirected graph. (This may be useful for
+     * visualization tasks).
+     * Specifically:
+     * <ul>
+     * <li/>Vertices are copied from <code>graph</code>.
+     * <li/>Directed edges are 'converted' into a single new undirected edge in the new graph.
+     * <li/>Each undirected edge (if any) in <code>graph</code> is 'recreated' with a new undirected edge in the new
+     * graph if <code>create_new</code> is true, or copied from <code>graph</code> otherwise.
+     * </ul>
+     * 
+     * @param graph     the graph to be transformed
+     * @param create_new specifies whether existing undirected edges are to be copied or recreated
+     * @param graph_factory used to create the new graph object
+     * @param edge_factory used to create new edges
+     * @return          the transformed <code>Graph</code>
+     */
+    public static <V,E> UndirectedGraph<V,E> toUndirected(Graph<V,E> graph, 
+               Factory<UndirectedGraph<V,E>> graph_factory,
+            Factory<E> edge_factory, boolean create_new)
+    {
+        UndirectedGraph<V,E> out = graph_factory.create();
+        
+        for (V v : graph.getVertices())
+            out.addVertex(v);
+        
+        for (E e : graph.getEdges())
+        {
+            Pair<V> endpoints = graph.getEndpoints(e);
+            V v1 = endpoints.getFirst();
+            V v2 = endpoints.getSecond();
+            E to_add;
+            if (graph.getEdgeType(e) == EdgeType.DIRECTED || create_new)
+                to_add = edge_factory.create();
+            else
+                to_add = e;
+            out.addEdge(to_add, v1, v2, EdgeType.UNDIRECTED);
+        }
+        return out;
+    }
+    
+    /**
+     * Transforms <code>graph</code> (which may be of any directionality)
+     * into a directed graph.  
+     * Specifically:
+     * <ul>
+     * <li/>Vertices are copied from <code>graph</code>.
+     * <li/>Undirected edges are 'converted' into two new antiparallel directed edges in the new graph.
+     * <li/>Each directed edge (if any) in <code>graph</code> is 'recreated' with a new edge in the new
+     * graph if <code>create_new</code> is true, or copied from <code>graph</code> otherwise.
+     * </ul>
+     * 
+     * @param graph     the graph to be transformed
+     * @param create_new specifies whether existing directed edges are to be copied or recreated
+     * @param graph_factory used to create the new graph object
+     * @param edge_factory used to create new edges
+     * @return          the transformed <code>Graph</code>
+     */
+    public static <V,E> Graph<V,E> toDirected(Graph<V,E> graph, Factory<DirectedGraph<V,E>> graph_factory,
+            Factory<E> edge_factory, boolean create_new)
+    {
+        DirectedGraph<V,E> out = graph_factory.create();
+        
+        for (V v : graph.getVertices())
+            out.addVertex(v);
+        
+        for (E e : graph.getEdges())
+        {
+            Pair<V> endpoints = graph.getEndpoints(e);
+            if (graph.getEdgeType(e) == EdgeType.UNDIRECTED)
+            {
+                V v1 = endpoints.getFirst();
+                V v2 = endpoints.getSecond();
+                out.addEdge(edge_factory.create(), v1, v2, EdgeType.DIRECTED);
+                out.addEdge(edge_factory.create(), v2, v1, EdgeType.DIRECTED);
+            }
+            else // if the edge is directed, just add it 
+            {
+                V source = graph.getSource(e);
+                V dest = graph.getDest(e);
+                E to_add = create_new ? edge_factory.create() : e;
+                out.addEdge(to_add, source, dest, EdgeType.DIRECTED);
+            }
+                
+        }
+        return out;
+    }
+}
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