1 /*
2 * Copyright 1999 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.awt.font;
27
28 import java.text.CharacterIterator;
29
30 class CharArrayIterator implements CharacterIterator {
31
32 private char[] chars;
33 private int pos;
34 private int begin;
35
36 CharArrayIterator(char[] chars) {
37
38 reset(chars, 0);
39 }
40
41 CharArrayIterator(char[] chars, int begin) {
42
43 reset(chars, begin);
44 }
45
46 /**
47 * Sets the position to getBeginIndex() and returns the character at that
48 * position.
49 * @return the first character in the text, or DONE if the text is empty
50 * @see getBeginIndex
51 */
52 public char first() {
53
54 pos = 0;
55 return current();
56 }
57
58 /**
59 * Sets the position to getEndIndex()-1 (getEndIndex() if the text is empty)
60 * and returns the character at that position.
61 * @return the last character in the text, or DONE if the text is empty
62 * @see getEndIndex
63 */
64 public char last() {
65
66 if (chars.length > 0) {
67 pos = chars.length-1;
68 }
69 else {
70 pos = 0;
71 }
72 return current();
73 }
74
75 /**
76 * Gets the character at the current position (as returned by getIndex()).
77 * @return the character at the current position or DONE if the current
78 * position is off the end of the text.
79 * @see getIndex
80 */
81 public char current() {
82
83 if (pos >= 0 && pos < chars.length) {
84 return chars[pos];
85 }
86 else {
87 return DONE;
88 }
89 }
90
91 /**
92 * Increments the iterator's index by one and returns the character
93 * at the new index. If the resulting index is greater or equal
94 * to getEndIndex(), the current index is reset to getEndIndex() and
95 * a value of DONE is returned.
96 * @return the character at the new position or DONE if the new
97 * position is off the end of the text range.
98 */
99 public char next() {
100
101 if (pos < chars.length-1) {
102 pos++;
103 return chars[pos];
104 }
105 else {
106 pos = chars.length;
107 return DONE;
108 }
109 }
110
111 /**
112 * Decrements the iterator's index by one and returns the character
113 * at the new index. If the current index is getBeginIndex(), the index
114 * remains at getBeginIndex() and a value of DONE is returned.
115 * @return the character at the new position or DONE if the current
116 * position is equal to getBeginIndex().
117 */
118 public char previous() {
119
120 if (pos > 0) {
121 pos--;
122 return chars[pos];
123 }
124 else {
125 pos = 0;
126 return DONE;
127 }
128 }
129
130 /**
131 * Sets the position to the specified position in the text and returns that
132 * character.
133 * @param position the position within the text. Valid values range from
134 * getBeginIndex() to getEndIndex(). An IllegalArgumentException is thrown
135 * if an invalid value is supplied.
136 * @return the character at the specified position or DONE if the specified position is equal to getEndIndex()
137 */
138 public char setIndex(int position) {
139
140 position -= begin;
141 if (position < 0 || position > chars.length) {
142 throw new IllegalArgumentException("Invalid index");
143 }
144 pos = position;
145 return current();
146 }
147
148 /**
149 * Returns the start index of the text.
150 * @return the index at which the text begins.
151 */
152 public int getBeginIndex() {
153 return begin;
154 }
155
156 /**
157 * Returns the end index of the text. This index is the index of the first
158 * character following the end of the text.
159 * @return the index after the last character in the text
160 */
161 public int getEndIndex() {
162 return begin+chars.length;
163 }
164
165 /**
166 * Returns the current index.
167 * @return the current index.
168 */
169 public int getIndex() {
170 return begin+pos;
171 }
172
173 /**
174 * Create a copy of this iterator
175 * @return A copy of this
176 */
177 public Object clone() {
178 CharArrayIterator c = new CharArrayIterator(chars, begin);
179 c.pos = this.pos;
180 return c;
181 }
182
183 void reset(char[] chars) {
184 reset(chars, 0);
185 }
186
187 void reset(char[] chars, int begin) {
188
189 this.chars = chars;
190 this.begin = begin;
191 pos = 0;
192 }
193 }
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