Class BoundablePairDistanceComparator

1
2	/*
3	* Copyright (c) 2017 Jia Yu.
4	*
5	* All rights reserved. This program and the accompanying materials
6	* are made available under the terms of the Eclipse Public License 2.0
7	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
8	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
9	* and the Eclipse Distribution License is available at
10	*
11	* http://www.eclipse.org/org/documents/edl-v10.php.
12	*/
13	package org.locationtech.jts.index.strtree;
14
15	import java.io.Serializable;
16	import java.util.Comparator;
17
18
19	/**
20	* The Class BoundablePairDistanceComparator. It implements Java comparator and is used
21	* as a parameter to sort the BoundablePair list.
22	*/
23	public class BoundablePairDistanceComparator implements Comparator<BoundablePair>, Serializable{
24
25	/** The normal order. */
26	boolean normalOrder;
27
28	/**
29	* Instantiates a new boundable pair distance comparator.
30	*
31	* @param normalOrder true puts the lowest record at the head of this queue.
32	* This is the natural order. PriorityQueue peek() will get the least element.
33	*/
34	public BoundablePairDistanceComparator(boolean normalOrder)
35	{
36	this.normalOrder = normalOrder;
37	}
38
39	/* (non-Javadoc)
40	* @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
41	*/
42	public int compare(BoundablePair p1, BoundablePair p2) {
43	double distance1 = p1.getDistance();
44	double distance2 = p2.getDistance();
45	if(this.normalOrder)
46	{
47	if (distance1 > distance2) {
48	return 1;
49	} else if (distance1 == distance2) {
50	return 0;
51	}
52	return -1;
53	}
54	else
55	{
56	if (distance1 > distance2) {
57	return -1;
58	} else if (distance1 == distance2) {
59	return 0;
60	}
61	return 1;
62	}
63
64	}
65	}
66