1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.text;
27
28 import java.io.InvalidObjectException;
29 import java.io.Serializable;
30 import java.util.HashMap;
31 import java.util.Map;
32 import java.util.Set;
33
34 /**
35 * An {@code AttributedCharacterIterator} allows iteration through both text and
36 * related attribute information.
37 *
38 * <p>
39 * An attribute is a key/value pair, identified by the key. No two
40 * attributes on a given character can have the same key.
41 *
42 * <p>The values for an attribute are immutable, or must not be mutated
43 * by clients or storage. They are always passed by reference, and not
44 * cloned.
45 *
46 * <p>A <em>run with respect to an attribute</em> is a maximum text range for
47 * which:
48 * <ul>
49 * <li>the attribute is undefined or {@code null} for the entire range, or
50 * <li>the attribute value is defined and has the same non-{@code null} value for the
51 * entire range.
52 * </ul>
53 *
54 * <p>A <em>run with respect to a set of attributes</em> is a maximum text range for
55 * which this condition is met for each member attribute.
56 *
57 * <p>When getting a run with no explicit attributes specified (i.e.,
58 * calling {@link #getRunStart()} and {@link #getRunLimit()}), any
59 * contiguous text segments having the same attributes (the same set
60 * of attribute/value pairs) are treated as separate runs if the
61 * attributes have been given to those text segments separately.
62 *
63 * <p>The returned indexes are limited to the range of the iterator.
64 *
65 * <p>The returned attribute information is limited to runs that contain
66 * the current character.
67 *
68 * <p>
69 * Attribute keys are instances of {@link AttributedCharacterIterator.Attribute} and its
70 * subclasses, such as {@link java.awt.font.TextAttribute}.
71 *
72 * @see AttributedCharacterIterator.Attribute
73 * @see java.awt.font.TextAttribute
74 * @see AttributedString
75 * @see Annotation
76 * @since 1.2
77 */
78
79 public interface AttributedCharacterIterator extends CharacterIterator {
80
81 /**
82 * Defines attribute keys that are used to identify text attributes. These
83 * keys are used in {@code AttributedCharacterIterator} and {@code AttributedString}.
84 * @see AttributedCharacterIterator
85 * @see AttributedString
86 * @since 1.2
87 */
88
89 public static class Attribute implements Serializable {
90
91 /**
92 * The name of this {@code Attribute}. The name is used primarily by {@code readResolve}
93 * to look up the corresponding predefined instance when deserializing
94 * an instance.
95 * @serial
96 */
97 private String name;
98
99 // table of all instances in this class, used by readResolve
100 private static final Map<String, Attribute> instanceMap = new HashMap<>(7);
101
102 /**
103 * Constructs an {@code Attribute} with the given name.
104 *
105 * @param name the name of {@code Attribute}
106 */
107 protected Attribute(String name) {
108 this.name = name;
109 if (this.getClass() == Attribute.class) {
110 instanceMap.put(name, this);
111 }
112 }
113
114 /**
115 * Compares two objects for equality. This version only returns true
116 * for {@code x.equals(y)} if {@code x} and {@code y} refer
117 * to the same object, and guarantees this for all subclasses.
118 */
119 public final boolean equals(Object obj) {
120 return super.equals(obj);
121 }
122
123 /**
124 * Returns a hash code value for the object. This version is identical to
125 * the one in {@code Object}, but is also final.
126 */
127 public final int hashCode() {
128 return super.hashCode();
129 }
130
131 /**
132 * Returns a string representation of the object. This version returns the
133 * concatenation of class name, {@code "("}, a name identifying the attribute
134 * and {@code ")"}.
135 */
136 public String toString() {
137 return getClass().getName() + "(" + name + ")";
138 }
139
140 /**
141 * Returns the name of the attribute.
142 *
143 * @return the name of {@code Attribute}
144 */
145 protected String getName() {
146 return name;
147 }
148
149 /**
150 * Resolves instances being deserialized to the predefined constants.
151 *
152 * @return the resolved {@code Attribute} object
153 * @throws InvalidObjectException if the object to resolve is not
154 * an instance of {@code Attribute}
155 */
156 protected Object readResolve() throws InvalidObjectException {
157 if (this.getClass() != Attribute.class) {
158 throw new InvalidObjectException("subclass didn't correctly implement readResolve");
159 }
160
161 Attribute instance = instanceMap.get(getName());
162 if (instance != null) {
163 return instance;
164 } else {
165 throw new InvalidObjectException("unknown attribute name");
166 }
167 }
168
169 /**
170 * Attribute key for the language of some text.
171 * <p> Values are instances of {@link java.util.Locale Locale}.
172 * @see java.util.Locale
173 */
174 public static final Attribute LANGUAGE = new Attribute("language");
175
176 /**
177 * Attribute key for the reading of some text. In languages where the written form
178 * and the pronunciation of a word are only loosely related (such as Japanese),
179 * it is often necessary to store the reading (pronunciation) along with the
180 * written form.
181 * <p>Values are instances of {@link Annotation} holding instances of {@link String}.
182 *
183 * @see Annotation
184 * @see java.lang.String
185 */
186 public static final Attribute READING = new Attribute("reading");
187
188 /**
189 * Attribute key for input method segments. Input methods often break
190 * up text into segments, which usually correspond to words.
191 * <p>Values are instances of {@link Annotation} holding a {@code null} reference.
192 * @see Annotation
193 */
194 public static final Attribute INPUT_METHOD_SEGMENT = new Attribute("input_method_segment");
195
196 // make sure the serial version doesn't change between compiler versions
197 private static final long serialVersionUID = -9142742483513960612L;
198
199 };
200
201 /**
202 * Returns the index of the first character of the run
203 * with respect to all attributes containing the current character.
204 *
205 * <p>Any contiguous text segments having the same attributes (the
206 * same set of attribute/value pairs) are treated as separate runs
207 * if the attributes have been given to those text segments separately.
208 *
209 * @return the index of the first character of the run
210 */
211 public int getRunStart();
212
213 /**
214 * Returns the index of the first character of the run
215 * with respect to the given {@code attribute} containing the current character.
216 *
217 * @param attribute the desired attribute.
218 * @return the index of the first character of the run
219 */
220 public int getRunStart(Attribute attribute);
221
222 /**
223 * Returns the index of the first character of the run
224 * with respect to the given {@code attributes} containing the current character.
225 *
226 * @param attributes a set of the desired attributes.
227 * @return the index of the first character of the run
228 */
229 public int getRunStart(Set<? extends Attribute> attributes);
230
231 /**
232 * Returns the index of the first character following the run
233 * with respect to all attributes containing the current character.
234 *
235 * <p>Any contiguous text segments having the same attributes (the
236 * same set of attribute/value pairs) are treated as separate runs
237 * if the attributes have been given to those text segments separately.
238 *
239 * @return the index of the first character following the run
240 */
241 public int getRunLimit();
242
243 /**
244 * Returns the index of the first character following the run
245 * with respect to the given {@code attribute} containing the current character.
246 *
247 * @param attribute the desired attribute
248 * @return the index of the first character following the run
249 */
250 public int getRunLimit(Attribute attribute);
251
252 /**
253 * Returns the index of the first character following the run
254 * with respect to the given {@code attributes} containing the current character.
255 *
256 * @param attributes a set of the desired attributes
257 * @return the index of the first character following the run
258 */
259 public int getRunLimit(Set<? extends Attribute> attributes);
260
261 /**
262 * Returns a map with the attributes defined on the current
263 * character.
264 *
265 * @return a map with the attributes defined on the current character
266 */
267 public Map<Attribute,Object> getAttributes();
268
269 /**
270 * Returns the value of the named {@code attribute} for the current character.
271 * Returns {@code null} if the {@code attribute} is not defined.
272 *
273 * @param attribute the desired attribute
274 * @return the value of the named {@code attribute} or {@code null}
275 */
276 public Object getAttribute(Attribute attribute);
277
278 /**
279 * Returns the keys of all attributes defined on the
280 * iterator's text range. The set is empty if no
281 * attributes are defined.
282 *
283 * @return the keys of all attributes
284 */
285 public Set<Attribute> getAllAttributeKeys();
286 };
287