Initial opendaylight infrastructure commit!!

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

diff --git a/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/filters/VertexPredicateFilter.java b/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/filters/VertexPredicateFilter.java
new file mode 100644 (file)
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+++ b/third-party/net.sf.jung2/src/main/java/edu/uci/ics/jung/algorithms/filters/VertexPredicateFilter.java
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+/*
+ * Created on May 19, 2008
+ *
+ * Copyright (c) 2008, 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.
+ */
+package edu.uci.ics.jung.algorithms.filters;
+
+import java.util.Collection;
+
+import org.apache.commons.collections15.Predicate;
+
+import edu.uci.ics.jung.graph.Graph;
+
+/**
+ * Transforms the input graph into one which contains only those vertices 
+ * that pass the specified <code>Predicate</code>.  The filtered graph
+ * is a copy of the original graph (same type, uses the same vertex and
+ * edge objects).  Only those edges whose entire incident vertex collection
+ * passes the predicate are copied into the new graph.
+ * 
+ * @author Joshua O'Madadhain
+ */
+public class VertexPredicateFilter<V,E> implements Filter<V,E>
+{
+    protected Predicate<V> vertex_pred;
+
+    /**
+     * Creates an instance based on the specified vertex <code>Predicate</code>.
+     * @param vertex_pred   the predicate that specifies which vertices to add to the filtered graph
+     */
+    public VertexPredicateFilter(Predicate<V> vertex_pred)
+    {
+        this.vertex_pred = vertex_pred;
+    }
+    
+    @SuppressWarnings("unchecked")
+       public Graph<V,E> transform(Graph<V,E> g)
+    {
+        Graph<V, E> filtered;
+        try
+        {
+            filtered = g.getClass().newInstance();
+        }
+        catch (InstantiationException e)
+        {
+            throw new RuntimeException("Unable to create copy of existing graph: ", e);
+        }
+        catch (IllegalAccessException e)
+        {
+            throw new RuntimeException("Unable to create copy of existing graph: ", e);
+        }
+
+        for (V v : g.getVertices())
+            if (vertex_pred.evaluate(v))
+                filtered.addVertex(v);
+        
+        Collection<V> filtered_vertices = filtered.getVertices();
+        
+        for (E e : g.getEdges())
+        {
+            Collection<V> incident = g.getIncidentVertices(e);
+            if (filtered_vertices.containsAll(incident))
+                filtered.addEdge(e, incident);
+        }
+        
+        return filtered;
+    }
+
+}