PolygonalExtracter.java
/*
* Copyright (c) 2023 Martin Davis.
*
* 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.Geometry;
import org.locationtech.jts.geom.GeometryCollection;
import org.locationtech.jts.geom.MultiPolygon;
import org.locationtech.jts.geom.Polygon;
/**
* Extracts the {@link Polygon} and {@link MultiPolygon} elements from a {@link Geometry}.
*/
public class PolygonalExtracter
{
/**
* Extracts the {@link Polygon} and {@link MultiPolygon} elements from a {@link Geometry}
* and adds them to the provided list.
*
* @param geom the geometry from which to extract
* @param list the list to add the extracted elements to
*/
public static List<Geometry> getPolygonals(Geometry geom, List<Geometry> list)
{
if (geom instanceof Polygon || geom instanceof MultiPolygon) {
list.add(geom);
}
else if (geom instanceof GeometryCollection) {
for (int i = 0; i < geom.getNumGeometries(); i++) {
getPolygonals(geom.getGeometryN(i), list);
}
}
// skip non-Polygonal elemental geometries
return list;
}
/**
* Extracts the {@link Polygon} and {@link MultiPolygon} elements from a {@link Geometry}
* and returns them in a list.
*
* @param geom the geometry from which to extract
*/
public static List<Geometry> getPolygonals(Geometry geom)
{
return getPolygonals(geom, new ArrayList<Geometry>());
}
}