Class ShortCircuitedGeometryVisitor

1	/*
2	* Copyright (c) 2016 Vivid Solutions.
3	*
4	* All rights reserved. This program and the accompanying materials
5	* are made available under the terms of the Eclipse Public License 2.0
6	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
7	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
8	* and the Eclipse Distribution License is available at
9	*
10	* http://www.eclipse.org/org/documents/edl-v10.php.
11	*/
12
13	package org.locationtech.jts.geom.util;
14
15	import org.locationtech.jts.geom.Geometry;
16	import org.locationtech.jts.geom.GeometryCollection;
17
18	/**
19	* A visitor to {@link Geometry} components, which
20	* allows short-circuiting when a defined condition holds.
21	*
22	* @version 1.7
23	*/
24	public abstract class ShortCircuitedGeometryVisitor
25	{
26	private boolean isDone = false;
27
28	public ShortCircuitedGeometryVisitor() {
29	}
30
31	public void applyTo(Geometry geom) {
32	for (int i = 0; i < geom.getNumGeometries() && ! isDone; i++) {
33	Geometry element = geom.getGeometryN(i);
34	if (! (element instanceof GeometryCollection)) {
35	visit(element);
36	if (isDone()) {
37	isDone = true;
38	return;
39	}
40	}
41	else
42	applyTo(element);
43	}
44	}
45
46	protected abstract void visit(Geometry element);
47
48	/**
49	* Reports whether visiting components can be terminated.
50	* Once this method returns <tt>true</tt>, it must
51	* continue to return <tt>true</tt> on every subsequent call.
52	*
53	* @return true if visiting can be terminated.
54	*/
55	protected abstract boolean isDone();
56	}
57