Mercurial > dive4elements > gnv-client
comparison gnv-artifacts/src/main/java/de/intevation/gnv/jfreechart/LevelOrderIndices.java @ 1119:7c4f81f74c47
merged gnv-artifacts
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:14:00 +0200 |
| parents | f953c9a559d8 |
| children |
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| 1027:fca4b5eb8d2f | 1119:7c4f81f74c47 |
|---|---|
| 1 /* | |
| 2 * Copyright (c) 2010 by Intevation GmbH | |
| 3 * | |
| 4 * This program is free software under the LGPL (>=v2.1) | |
| 5 * Read the file LGPL.txt coming with the software for details | |
| 6 * or visit http://www.gnu.org/licenses/ if it does not exist. | |
| 7 */ | |
| 8 | |
| 9 package de.intevation.gnv.jfreechart; | |
| 10 | |
| 11 import java.util.LinkedList; | |
| 12 | |
| 13 /** | |
| 14 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a> | |
| 15 */ | |
| 16 public class LevelOrderIndices | |
| 17 { | |
| 18 public interface Visitor { | |
| 19 | |
| 20 Object visit(int index); | |
| 21 } | |
| 22 | |
| 23 | |
| 24 protected int from; | |
| 25 | |
| 26 protected int to; | |
| 27 | |
| 28 | |
| 29 public LevelOrderIndices() { | |
| 30 } | |
| 31 | |
| 32 | |
| 33 public LevelOrderIndices(int to) { | |
| 34 this(0, to); | |
| 35 } | |
| 36 | |
| 37 | |
| 38 public LevelOrderIndices(int from, int to) { | |
| 39 this.from = Math.min(from, to); | |
| 40 this.to = Math.max(from, to); | |
| 41 } | |
| 42 | |
| 43 | |
| 44 public Object visit(Visitor visitor) { | |
| 45 LinkedList<int[]> queue = new LinkedList<int[]>(); | |
| 46 | |
| 47 queue.add(new int [] { from, to }); | |
| 48 | |
| 49 while (!queue.isEmpty()) { | |
| 50 int [] pair = queue.remove(); | |
| 51 | |
| 52 int mid = (pair[0] + pair[1]) >> 1; | |
| 53 | |
| 54 Object result = visitor.visit(mid); | |
| 55 | |
| 56 if (result != null) { | |
| 57 return result; | |
| 58 } | |
| 59 | |
| 60 if (mid-1 >= pair[0]) { | |
| 61 queue.add(new int [] { pair[0], mid-1 }); | |
| 62 } | |
| 63 | |
| 64 if (mid+1 <= pair[1]) { | |
| 65 pair[0] = mid+1; | |
| 66 queue.add(pair); | |
| 67 } | |
| 68 } | |
| 69 | |
| 70 return null; | |
| 71 } | |
| 72 } | |
| 73 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 : |