01: /*
02: * The JTS Topology Suite is a collection of Java classes that
03: * implement the fundamental operations required to validate a given
04: * geo-spatial data set to a known topological specification.
05: *
06: * Copyright (C) 2001 Vivid Solutions
07: *
08: * This library is free software; you can redistribute it and/or
09: * modify it under the terms of the GNU Lesser General Public
10: * License as published by the Free Software Foundation; either
11: * version 2.1 of the License, or (at your option) any later version.
12: *
13: * This library is distributed in the hope that it will be useful,
14: * but WITHOUT ANY WARRANTY; without even the implied warranty of
15: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16: * Lesser General Public License for more details.
17: *
18: * You should have received a copy of the GNU Lesser General Public
19: * License along with this library; if not, write to the Free Software
20: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21: *
22: * For more information, contact:
23: *
24: * Vivid Solutions
25: * Suite #1A
26: * 2328 Government Street
27: * Victoria BC V8T 5G5
28: * Canada
29: *
30: * (250)385-6040
31: * www.vividsolutions.com
32: */
33: package com.vividsolutions.jts.operation.distance;
34:
35: import java.util.*;
36: import com.vividsolutions.jts.geom.*;
37:
38: /**
39: * Extracts a single point
40: * from each connected element in a Geometry
41: * (e.g. a polygon, linestring or point)
42: * and returns them in a list
43: *
44: * @version 1.7
45: */
46: public class ConnectedElementPointFilter implements GeometryFilter {
47:
48: /**
49: * Returns a list containing a Coordinate from each Polygon, LineString, and Point
50: * found inside the specified geometry. Thus, if the specified geometry is
51: * not a GeometryCollection, an empty list will be returned.
52: */
53: public static List getCoordinates(Geometry geom) {
54: List pts = new ArrayList();
55: geom.apply(new ConnectedElementPointFilter(pts));
56: return pts;
57: }
58:
59: private List pts;
60:
61: ConnectedElementPointFilter(List pts) {
62: this .pts = pts;
63: }
64:
65: public void filter(Geometry geom) {
66: if (geom instanceof Point || geom instanceof LineString
67: || geom instanceof Polygon)
68: pts.add(geom.getCoordinate());
69: }
70:
71: }
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