Mercurial > dive4elements > gnv-client
comparison gnv-artifacts/src/main/java/de/intevation/gnv/jfreechart/LevelOrderIndices.java @ 875:5e9efdda6894
merged gnv-artifacts/1.0
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:13:56 +0200 |
| parents | 22c18083225e |
| children | f953c9a559d8 |
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| 722:bb3ffe7d719e | 875:5e9efdda6894 |
|---|---|
| 1 package de.intevation.gnv.jfreechart; | |
| 2 | |
| 3 import java.util.LinkedList; | |
| 4 | |
| 5 /** | |
| 6 * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a> | |
| 7 */ | |
| 8 public class LevelOrderIndices | |
| 9 { | |
| 10 public interface Visitor { | |
| 11 | |
| 12 Object visit(int index); | |
| 13 } | |
| 14 | |
| 15 | |
| 16 protected int from; | |
| 17 | |
| 18 protected int to; | |
| 19 | |
| 20 | |
| 21 public LevelOrderIndices() { | |
| 22 } | |
| 23 | |
| 24 | |
| 25 public LevelOrderIndices(int to) { | |
| 26 this(0, to); | |
| 27 } | |
| 28 | |
| 29 | |
| 30 public LevelOrderIndices(int from, int to) { | |
| 31 this.from = Math.min(from, to); | |
| 32 this.to = Math.max(from, to); | |
| 33 } | |
| 34 | |
| 35 | |
| 36 public Object visit(Visitor visitor) { | |
| 37 LinkedList<int[]> queue = new LinkedList<int[]>(); | |
| 38 | |
| 39 queue.add(new int [] { from, to }); | |
| 40 | |
| 41 while (!queue.isEmpty()) { | |
| 42 int [] pair = queue.remove(); | |
| 43 | |
| 44 int mid = (pair[0] + pair[1]) >> 1; | |
| 45 | |
| 46 Object result = visitor.visit(mid); | |
| 47 | |
| 48 if (result != null) { | |
| 49 return result; | |
| 50 } | |
| 51 | |
| 52 if (mid-1 >= pair[0]) { | |
| 53 queue.add(new int [] { pair[0], mid-1 }); | |
| 54 } | |
| 55 | |
| 56 if (mid+1 <= pair[1]) { | |
| 57 pair[0] = mid+1; | |
| 58 queue.add(pair); | |
| 59 } | |
| 60 } | |
| 61 | |
| 62 return null; | |
| 63 } | |
| 64 } | |
| 65 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 : |