/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.graph.build.line;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.Graphable;
import org.geotools.graph.structure.Node;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineSegment;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.MultiLineString;
/**
* Builds a graph representing a line network in which edges in the network are
* represented by LineString geometries. This implementation is a wrapper around
* a LineGraphGenerator which sets underlying edge objects to be LineString
* objects, and underlying Node objects to be Point objects. While generating
* the graph, the generator uses the visited flag of created components to
* determine when to create underlying objects. For this reason it is not recommended
* to modify the visited flag of any graph components.
*
* @see com.vividsolutions.jts.geom.LineString
* @see com.vividsolutions.jts.geom.Point
*
* @author Justin Deoliveira, Refractions Research Inc, jdeolive@refractions.net
*
*
* @source $URL$
*/
public class LineStringGraphGenerator extends BasicLineGraphGenerator {
private static GeometryFactory gf = new GeometryFactory();
public Graphable add(Object obj) {
LineString ls = null;
if (obj instanceof MultiLineString)
ls = (LineString) ((MultiLineString)obj).getGeometryN(0);
else
ls = (LineString)obj;
//parent class expects a line segment
Edge e = (Edge)super.add(
new LineSegment(
ls.getCoordinateN(0), ls.getCoordinateN(ls.getNumPoints()-1)
)
);
//over write object to be the linestring
e.setObject(ls);
return(e);
}
public Graphable remove(Object obj) {
LineString ls = (LineString)obj;
//parent ecpexts a line segment
return(
super.remove(
new LineSegment(
ls.getCoordinateN(0), ls.getCoordinateN(ls.getNumPoints()-1)
)
)
);
}
public Graphable get(Object obj) {
LineString ls = (LineString)obj;
//parent ecpexts a line segment
return(
super.get(
new LineSegment(
ls.getCoordinateN(0), ls.getCoordinateN(ls.getNumPoints()-1)
)
)
);
}
protected void setObject(Node n, Object obj) {
//set underlying object to be point instead of coordinate
Coordinate c = (Coordinate)obj;
n.setObject(gf.createPoint(c));
}
// /** underlying line graph generator **/
// private LineGraphGenerator m_generator;
//
// /**
// * Constructs a new LineStringGraphGenerator.
// *
// */
// public LineStringGraphGenerator() {
// this(new BasicLineGraphGenerator());
// }
//
// /**
// * Constructs a new LineStringGraphGenerator.
// *
// * @param generator Underlying generator.
// */
// public LineStringGraphGenerator(LineGraphGenerator generator) {
// m_generator = generator;
// }
//
// /**
// * Adds a LineString object to the graph. An edge is created to represent the
// * LineString and its underlying object is set to the LineString.
// *
// * @param obj A LineString.
// *
// * @see GraphGenerator#add(Object)
// */
// public Graphable add(Object obj) {
// LineString line = (LineString)obj;
// Coordinate[] c = line.getCoordinates();
//
// //instruct the underlying line graph generate and edge represented by
// // the endpoints of the linestring, set the underlying object to be the
// //linstring itself
// Edge e = (Edge)m_generator.add(
// new LineSegment(c[0], c[c.length-1])
// );
// e.setObject(line);
//
// //check nodes of edge, if not visited, set object to point
// if (!e.getNodeA().isVisited()) {
// e.getNodeA().setVisited(true);
// e.getNodeA().setObject(line.getPointN(0));
// }
//
// if (!e.getNodeB().isVisited()) {
// e.getNodeB().setVisited(true);
// e.getNodeB().setObject(line.getPointN(c.length-1));
// }
//
// return(e);
// }
//
// /**
// * Returns the edge created to represent a LineString object.
// *
// * @param obj A LineString.
// *
// * @see GraphGenerator#get(Object)
// */
// public Graphable get(Object obj) {
// LineString line = (LineString)obj;
// Coordinate[] c = line.getCoordinates();
//
// Edge e = (Edge)m_generator.get(
// new LineSegment(c[0], c[c.length-1])
// );
//
// return(e);
// }
//
// /**
// * Removes an edge from the graph which represents a LineString object.
// *
// * @param A LineString.
// *
// * @see GraphGenerator#remove(Object)
// */
// public Graphable remove(Object obj) {
// LineString line = (LineString)obj;
// Coordinate[] c = line.getCoordinates();
//
// Edge e = (Edge)m_generator.remove(
// new LineSegment(c[0], c[c.length-1])
// );
//
// return(e);
// }
//
// /**
// * Sets the underlying builder of the underlying generator.
// *
// * @see GraphGenerator#setGraphBuilder(GraphBuilder)
// */
// public void setGraphBuilder(GraphBuilder builder) {
// m_generator.setGraphBuilder(builder);
// }
//
// /**
// * Returns the underlying builder of the underlying generator.
// *
// * @see GraphGenerator#getGraphBuilder()
// */
// public GraphBuilder getGraphBuilder() {
// return(m_generator.getGraphBuilder());
// }
//
// /**
// * @see GraphGenerator#getGraph()
// */
// public Graph getGraph() {
// return(m_generator.getGraph());
// }
//
// public Node getNode(Coordinate c) {
// return(m_generator.getNode(c));
// }
//
// public Edge getEdge(Coordinate c1, Coordinate c2) {
// return(m_generator.getEdge(c1,c2));
// }
}