/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* 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
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.revolsys.geometry.operation.linemerge;
import com.revolsys.geometry.model.Point;
import com.revolsys.geometry.planargraph.DirectedEdge;
import com.revolsys.geometry.planargraph.Node;
import com.revolsys.geometry.util.Assert;
/**
* A {@link com.revolsys.geometry.planargraph.DirectedEdge} of a
* {@link LineMergeGraph}.
*
* @version 1.7
*/
public class LineMergeDirectedEdge extends DirectedEdge {
/**
* Constructs a LineMergeDirectedEdge connecting the <code>from</code> node to the
* <code>to</code> node.
*
* @param directionPt
* specifies this DirectedEdge's direction (given by an imaginary
* line from the <code>from</code> node to <code>directionPt</code>)
* @param edgeDirection
* whether this DirectedEdge's direction is the same as or
* opposite to that of the parent Edge (if any)
*/
public LineMergeDirectedEdge(final Node from, final Node to, final Point directionPt,
final boolean edgeDirection) {
super(from, to, directionPt, edgeDirection);
}
/**
* Returns the directed edge that starts at this directed edge's end point, or null
* if there are zero or multiple directed edges starting there.
* @return the directed edge
*/
public LineMergeDirectedEdge getNext() {
if (getToNode().getDegree() != 2) {
return null;
}
if (getToNode().getOutEdges().getEdges().get(0) == getSym()) {
return (LineMergeDirectedEdge)getToNode().getOutEdges().getEdges().get(1);
}
Assert.isTrue(getToNode().getOutEdges().getEdges().get(1) == getSym());
return (LineMergeDirectedEdge)getToNode().getOutEdges().getEdges().get(0);
}
}