J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | * |
| 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 21 | * have any questions. |
| 22 | */ |
| 23 | |
| 24 | import java.text.BreakIterator; |
| 25 | import java.text.CharacterIterator; |
| 26 | import java.util.ArrayList; |
| 27 | import java.util.Collections; |
| 28 | import java.util.Iterator; |
| 29 | import java.util.List; |
| 30 | import java.util.NoSuchElementException; |
| 31 | |
| 32 | public class MirroredBreakIterator extends BreakIterator { |
| 33 | private final List<Integer> boundaries; |
| 34 | private int charIndex; |
| 35 | private int boundaryIndex; |
| 36 | |
| 37 | MirroredBreakIterator(BreakIterator bi) { |
| 38 | List<Integer> b = new ArrayList<Integer>(); |
| 39 | int i = bi.first(); |
| 40 | charIndex = i; |
| 41 | for (; i != DONE; i = bi.next()) { |
| 42 | b.add(i); |
| 43 | } |
| 44 | boundaries = Collections.unmodifiableList(b); |
| 45 | } |
| 46 | |
| 47 | @Override |
| 48 | public Object clone() { |
| 49 | try { |
| 50 | return super.clone(); |
| 51 | } catch (Exception e) { |
| 52 | throw new RuntimeException("clone failed", e); |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | @Override |
| 57 | public int first() { |
| 58 | return changeIndices(0); |
| 59 | } |
| 60 | |
| 61 | @Override |
| 62 | public int last() { |
| 63 | return changeIndices(boundaries.size() - 1); |
| 64 | } |
| 65 | |
| 66 | @Override |
| 67 | public int next(int n) { |
| 68 | if (n == 0) { |
| 69 | return current(); |
| 70 | } |
| 71 | int newBoundary = boundaryIndex + n; |
| 72 | if (newBoundary < 0) { |
| 73 | first(); |
| 74 | return DONE; |
| 75 | } |
| 76 | if (newBoundary > lastBoundary()) { |
| 77 | last(); |
| 78 | return DONE; |
| 79 | } |
| 80 | return changeIndices(newBoundary); |
| 81 | } |
| 82 | |
| 83 | @Override |
| 84 | public int next() { |
| 85 | if (boundaryIndex == lastBoundary()) { |
| 86 | return DONE; |
| 87 | } |
| 88 | return changeIndices(boundaryIndex + 1); |
| 89 | } |
| 90 | |
| 91 | @Override |
| 92 | public int previous() { |
| 93 | if (boundaryIndex == 0) { |
| 94 | return DONE; |
| 95 | } |
| 96 | return changeIndices(boundaryIndex - 1); |
| 97 | } |
| 98 | |
| 99 | @Override |
| 100 | public int following(int offset) { |
| 101 | validateOffset(offset); |
| 102 | for (int b = 0; b <= lastBoundary(); b++) { |
| 103 | int i = boundaries.get(b); |
| 104 | if (i > offset) { |
| 105 | return changeIndices(i, b); |
| 106 | } |
| 107 | } |
| 108 | return DONE; |
| 109 | } |
| 110 | |
| 111 | @Override |
| 112 | public int preceding(int offset) { |
| 113 | validateOffset(offset); |
| 114 | for (int b = lastBoundary(); b >= 0; b--) { |
| 115 | int i = boundaries.get(b); |
| 116 | if (i < offset) { |
| 117 | return changeIndices(i, b); |
| 118 | } |
| 119 | } |
| 120 | return DONE; |
| 121 | } |
| 122 | |
| 123 | @Override |
| 124 | public boolean isBoundary(int offset) { |
| 125 | // Call the default impelementation in BreakIterator |
| 126 | return super.isBoundary(offset); |
| 127 | } |
| 128 | |
| 129 | @Override |
| 130 | public int current() { |
| 131 | return charIndex; |
| 132 | } |
| 133 | |
| 134 | @Override |
| 135 | public CharacterIterator getText() { |
| 136 | throw new UnsupportedOperationException(); |
| 137 | } |
| 138 | |
| 139 | @Override |
| 140 | public void setText(CharacterIterator newText) { |
| 141 | throw new UnsupportedOperationException(); |
| 142 | } |
| 143 | |
| 144 | private int lastBoundary() { |
| 145 | return boundaries.size() - 1; |
| 146 | } |
| 147 | |
| 148 | private int changeIndices(int newCharIndex, int newBoundary) { |
| 149 | boundaryIndex = newBoundary; |
| 150 | return charIndex = newCharIndex; |
| 151 | } |
| 152 | |
| 153 | private int changeIndices(int newBoundary) { |
| 154 | try { |
| 155 | return changeIndices(boundaries.get(newBoundary), newBoundary); |
| 156 | } catch (IndexOutOfBoundsException e) { |
| 157 | throw new IllegalArgumentException(e); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | private void validateOffset(int offset) { |
| 162 | if (offset < boundaries.get(0) || offset > boundaries.get(lastBoundary())) { |
| 163 | throw new IllegalArgumentException(); |
| 164 | } |
| 165 | } |
| 166 | } |