]>
Commit | Line | Data |
---|---|---|
1b2798f6 EK |
1 | /******************************************************************************* |
2 | * Copyright (c) 2000, 2011 IBM Corporation and others. | |
3 | * All rights reserved. This program and the accompanying materials | |
4 | * are made available under the terms of the Eclipse Public License v1.0 | |
5 | * which accompanies this distribution, and is available at | |
6 | * http://www.eclipse.org/legal/epl-v10.html | |
7 | * | |
8 | * Contributors: | |
9 | * IBM Corporation - initial API and implementation | |
10 | *******************************************************************************/ | |
11 | package org.eclipse.jdt.internal.ui.text; | |
12 | ||
13 | import java.text.CharacterIterator; | |
14 | ||
15 | import org.eclipse.core.runtime.Assert; | |
16 | ||
17 | ||
18 | ||
19 | /** | |
20 | * A <code>CharSequence</code> based implementation of <code>CharacterIterator</code>. | |
21 | * | |
22 | * @since 3.0 | |
23 | */ | |
24 | public class SequenceCharacterIterator implements CharacterIterator { | |
25 | ||
26 | private int fIndex= -1; | |
27 | private final CharSequence fSequence; | |
28 | private final int fFirst; | |
29 | private final int fLast; | |
30 | ||
31 | private void invariant() { | |
32 | Assert.isTrue(fIndex >= fFirst); | |
33 | Assert.isTrue(fIndex <= fLast); | |
34 | } | |
35 | ||
36 | /** | |
37 | * Creates an iterator for the entire sequence. | |
38 | * | |
39 | * @param sequence the sequence backing this iterator | |
40 | */ | |
41 | public SequenceCharacterIterator(CharSequence sequence) { | |
42 | this(sequence, 0); | |
43 | } | |
44 | ||
45 | /** | |
46 | * Creates an iterator. | |
47 | * | |
48 | * @param sequence the sequence backing this iterator | |
49 | * @param first the first character to consider | |
50 | * @throws IllegalArgumentException if the indices are out of bounds | |
51 | */ | |
52 | public SequenceCharacterIterator(CharSequence sequence, int first) throws IllegalArgumentException { | |
53 | this(sequence, first, sequence.length()); | |
54 | } | |
55 | ||
56 | /** | |
57 | * Creates an iterator. | |
58 | * | |
59 | * @param sequence the sequence backing this iterator | |
60 | * @param first the first character to consider | |
61 | * @param last the last character index to consider | |
62 | * @throws IllegalArgumentException if the indices are out of bounds | |
63 | */ | |
64 | public SequenceCharacterIterator(CharSequence sequence, int first, int last) throws IllegalArgumentException { | |
65 | if (sequence == null) | |
66 | throw new NullPointerException(); | |
67 | if (first < 0 || first > last) | |
68 | throw new IllegalArgumentException(); | |
69 | if (last > sequence.length()) | |
70 | throw new IllegalArgumentException(); | |
71 | fSequence= sequence; | |
72 | fFirst= first; | |
73 | fLast= last; | |
74 | fIndex= first; | |
75 | invariant(); | |
76 | } | |
77 | ||
78 | /* | |
79 | * @see java.text.CharacterIterator#first() | |
80 | */ | |
81 | public char first() { | |
82 | return setIndex(getBeginIndex()); | |
83 | } | |
84 | ||
85 | /* | |
86 | * @see java.text.CharacterIterator#last() | |
87 | */ | |
88 | public char last() { | |
89 | if (fFirst == fLast) | |
90 | return setIndex(getEndIndex()); | |
91 | else | |
92 | return setIndex(getEndIndex() - 1); | |
93 | } | |
94 | ||
95 | /* | |
96 | * @see java.text.CharacterIterator#current() | |
97 | */ | |
98 | public char current() { | |
99 | if (fIndex >= fFirst && fIndex < fLast) | |
100 | return fSequence.charAt(fIndex); | |
101 | else | |
102 | return DONE; | |
103 | } | |
104 | ||
105 | /* | |
106 | * @see java.text.CharacterIterator#next() | |
107 | */ | |
108 | public char next() { | |
109 | return setIndex(Math.min(fIndex + 1, getEndIndex())); | |
110 | } | |
111 | ||
112 | /* | |
113 | * @see java.text.CharacterIterator#previous() | |
114 | */ | |
115 | public char previous() { | |
116 | if (fIndex > getBeginIndex()) { | |
117 | return setIndex(fIndex - 1); | |
118 | } else { | |
119 | return DONE; | |
120 | } | |
121 | } | |
122 | ||
123 | /* | |
124 | * @see java.text.CharacterIterator#setIndex(int) | |
125 | */ | |
126 | public char setIndex(int position) { | |
127 | if (position >= getBeginIndex() && position <= getEndIndex()) | |
128 | fIndex= position; | |
129 | else | |
130 | throw new IllegalArgumentException(); | |
131 | ||
132 | invariant(); | |
133 | return current(); | |
134 | } | |
135 | ||
136 | /* | |
137 | * @see java.text.CharacterIterator#getBeginIndex() | |
138 | */ | |
139 | public int getBeginIndex() { | |
140 | return fFirst; | |
141 | } | |
142 | ||
143 | /* | |
144 | * @see java.text.CharacterIterator#getEndIndex() | |
145 | */ | |
146 | public int getEndIndex() { | |
147 | return fLast; | |
148 | } | |
149 | ||
150 | /* | |
151 | * @see java.text.CharacterIterator#getIndex() | |
152 | */ | |
153 | public int getIndex() { | |
154 | return fIndex; | |
155 | } | |
156 | ||
157 | /* | |
158 | * @see java.text.CharacterIterator#clone() | |
159 | */ | |
160 | @Override | |
161 | public Object clone() { | |
162 | try { | |
163 | return super.clone(); | |
164 | } catch (CloneNotSupportedException e) { | |
165 | throw new InternalError(); | |
166 | } | |
167 | } | |
168 | } |