/*
* 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.vividsolutions.jts.geom.util;
import java.util.*;
import com.vividsolutions.jts.geom.*;
/**
* Extracts the components of a given type from a {@link Geometry}.
*
* @version 1.7
*/
public class GeometryExtracter
implements GeometryFilter
{
protected static boolean isOfClass(Object o, Class clz)
{
return clz.isAssignableFrom(o.getClass());
// return o.getClass() == clz;
}
/**
* Extracts the components of type <tt>clz</tt> from a {@link Geometry}
* and adds them to the provided {@link List}.
*
* @param geom the geometry from which to extract
* @param list the list to add the extracted elements to
*/
public static List extract(Geometry geom, Class clz, List list)
{
if (isOfClass(geom, clz)) {
list.add(geom);
}
else if (geom instanceof GeometryCollection) {
geom.apply(new GeometryExtracter(clz, list));
}
// skip non-LineString elemental geometries
return list;
}
/**
* Extracts the components of type <tt>clz</tt> from a {@link Geometry}
* and returns them in a {@link List}.
*
* @param geom the geometry from which to extract
*/
public static List extract(Geometry geom, Class clz)
{
return extract(geom, clz, new ArrayList());
}
private Class clz;
private List comps;
/**
* Constructs a filter with a list in which to store the elements found.
*
* @param clz the class of the components to extract (null means all types)
* @param comps the list to extract into
*/
public GeometryExtracter(Class clz, List comps)
{
this.clz = clz;
this.comps = comps;
}
public void filter(Geometry geom)
{
if (clz == null || isOfClass(geom, clz)) comps.add(geom);
}
}