Mercurial > dive4elements > gnv-client
comparison gnv-artifacts/src/main/java/de/intevation/gnv/jfreechart/LevelOrderIndices.java @ 540:80630520e25a
merged gnv-artifacts/0.4
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:13:49 +0200 |
| parents | 20a480753ff9 |
| children | c4156275c1e1 |
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| 415:9f4a0b990d27 | 540:80630520e25a |
|---|---|
| 1 package de.intevation.gnv.jfreechart; | |
| 2 | |
| 3 import java.util.LinkedList; | |
| 4 | |
| 5 /** | |
| 6 * @author Sascha L. Teichmann (sascha.teichmann@intevation.de) | |
| 7 */ | |
| 8 public class LevelOrderIndices | |
| 9 { | |
| 10 public interface Visitor { | |
| 11 Object visit(int index); | |
| 12 } | |
| 13 | |
| 14 protected int from; | |
| 15 protected int to; | |
| 16 | |
| 17 public LevelOrderIndices() { | |
| 18 } | |
| 19 | |
| 20 public LevelOrderIndices(int to) { | |
| 21 this(0, to); | |
| 22 } | |
| 23 | |
| 24 public LevelOrderIndices(int from, int to) { | |
| 25 this.from = Math.min(from, to); | |
| 26 this.to = Math.max(from, to); | |
| 27 } | |
| 28 | |
| 29 public Object visit(Visitor visitor) { | |
| 30 LinkedList<int[]> queue = new LinkedList<int[]>(); | |
| 31 | |
| 32 queue.add(new int [] { from, to }); | |
| 33 | |
| 34 while (!queue.isEmpty()) { | |
| 35 int [] pair = queue.remove(); | |
| 36 | |
| 37 int mid = (pair[0] + pair[1]) >> 1; | |
| 38 | |
| 39 Object result = visitor.visit(mid); | |
| 40 | |
| 41 if (result != null) { | |
| 42 return result; | |
| 43 } | |
| 44 | |
| 45 if (mid-1 >= pair[0]) { | |
| 46 queue.add(new int [] { pair[0], mid-1 }); | |
| 47 } | |
| 48 | |
| 49 if (mid+1 <= pair[1]) { | |
| 50 pair[0] = mid+1; | |
| 51 queue.add(pair); | |
| 52 } | |
| 53 } | |
| 54 | |
| 55 return null; | |
| 56 } | |
| 57 } | |
| 58 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 : |