edu.uci.ics.jung.visualization.util.ParallelEdgeIndexFunction Maven / Gradle / Ivy
/*
* Created on Sep 24, 2005
*
* Copyright (c) 2005, The JUNG Authors
*
* All rights reserved.
*
* This software is open-source under the BSD license; see either
* "license.txt" or
* https://github.com/jrtom/jung/blob/master/LICENSE for a description.
*/
package edu.uci.ics.jung.visualization.util;
import com.google.common.graph.EndpointPair;
import com.google.common.graph.Network;
import java.util.HashMap;
import java.util.Map;
/**
* A class which creates and maintains indices for parallel edges. Parallel edges are defined here
* to be the collection of edges that are returned by graph.edgesConnecting(v, w) for
* some v and w.
*
* At this time, users are responsible for resetting the indices (by calling reset()
* ) if changes to the graph make it appropriate.
*
* @author Joshua O'Madadhain
* @author Tom Nelson
*/
public class ParallelEdgeIndexFunction implements EdgeIndexFunction {
protected Map edge_index = new HashMap<>();
public int getIndex(Context, E> context) {
Network network = context.graph;
E edge = context.element;
Integer index = edge_index.get(edge);
if (index == null) {
EndpointPair endpoints = network.incidentNodes(edge);
N u = endpoints.nodeU();
N v = endpoints.nodeV();
int count = 0;
for (E connectingEdge : network.edgesConnecting(u, v)) {
edge_index.put(connectingEdge, count++);
}
return edge_index.get(edge);
}
return index;
}
public void reset(Context, E> context) {
edge_index.remove(context.element);
}
public void reset() {
edge_index.clear();
}
}