ComponentCoordinateExtracter.java
/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.geom.util;
import java.util.ArrayList;
import java.util.List;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryComponentFilter;
import org.locationtech.jts.geom.LineString;
import org.locationtech.jts.geom.Point;
/**
* Extracts a representative {@link Coordinate}
* from each connected component of a {@link Geometry}.
*
* @version 1.9
*/
public class ComponentCoordinateExtracter
implements GeometryComponentFilter
{
/**
* Extracts a representative {@link Coordinate}
* from each connected component in a geometry.
* <p>
* If more than one geometry is to be processed, it is more
* efficient to create a single {@link ComponentCoordinateExtracter} instance
* and pass it to each geometry.
*
* @param geom the Geometry from which to extract
* @return a list of representative Coordinates
*/
public static List getCoordinates(Geometry geom)
{
List coords = new ArrayList();
geom.apply(new ComponentCoordinateExtracter(coords));
return coords;
}
private List coords;
/**
* Constructs a LineExtracterFilter with a list in which to store LineStrings found.
*/
public ComponentCoordinateExtracter(List coords)
{
this.coords = coords;
}
public void filter(Geometry geom)
{
if (geom.isEmpty())
return;
// add coordinates from connected components
if (geom instanceof LineString
|| geom instanceof Point)
coords.add(geom.getCoordinate());
}
}