001    /* AttributedCharacterIterator.java -- Iterate over attributes
002       Copyright (C) 1998, 1999, 2004, 2006, Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010     
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.text;
040    
041    import java.io.InvalidObjectException;
042    import java.io.Serializable;
043    import java.util.Map;
044    import java.util.Set;
045    
046    /**
047     * This interface extends the <code>CharacterIterator</code> interface
048     * in order to support iteration over character attributes as well as
049     * over the characters themselves.
050     * <p>
051     * In addition to attributes of specific characters, this interface
052     * supports the concept of the "attribute run", which is an attribute
053     * that is defined for a particular value across an entire range of
054     * characters or which is undefined over a range of characters.
055     *
056     * @since 1.2
057     * 
058     * @author Aaron M. Renn (arenn@urbanophile.com)
059     * @since 1.2
060     */
061    public interface AttributedCharacterIterator extends CharacterIterator
062    {
063      /**
064       * Defines attribute keys that are used as text attributes.
065       */
066      public static class Attribute implements Serializable
067      {
068        private static final long serialVersionUID = -9142742483513960612L;
069    
070        /**
071         * This is the attribute for the language of the text.  The value of
072         * attributes of this key type are instances of <code>Locale</code>.
073         */
074        public static final Attribute LANGUAGE = new Attribute("language");
075    
076        /**
077         * This is the attribute for the reading form of text.  This is used
078         * for storing pronunciation along with the written text for languages
079         * which need it.  The value of attributes of this key type are
080         * instances of <code>Annotation</code> which wrappers a 
081         * <code>String</code>.
082         */
083        public static final Attribute READING = new Attribute("reading");
084    
085        /**
086         * This is the attribute for input method segments.  The value of attributes
087         * of this key type are instances of <code>Annotation</code> which wrapper
088         * a <code>String</code>.
089         */
090        public static final Attribute INPUT_METHOD_SEGMENT =
091          new Attribute("input_method_segment");
092    
093        /**
094         * The name of the attribute key
095         * @serial
096         */
097        private String name;
098    
099        /**
100         * Initializes a new instance of this class with the specified name.
101         *
102         * @param name The name of this attribute key.
103         */
104        protected Attribute(String name)
105        {
106          this.name = name;
107        }
108    
109        /**
110         * Returns the name of this attribute.
111         *
112         * @return The attribute name
113         */
114        protected String getName()
115        {
116          return name;
117        }
118    
119        /**
120         * Resolves an instance of 
121         * <code>AttributedCharacterIterator.Attribute</code>
122         * that is being deserialized to one of the three pre-defined attribute
123         * constants.  It does this by comparing the names of the attributes.  The
124         * constant that the deserialized object resolves to is returned.
125         *
126         * @return The resolved contant value
127         *
128         * @exception InvalidObjectException If the object being deserialized 
129         *            cannot be resolved.
130         */
131        protected Object readResolve() throws InvalidObjectException
132        {
133          if (getName().equals(READING.getName()))
134            return READING;
135    
136          if (getName().equals(LANGUAGE.getName()))
137            return LANGUAGE;
138    
139          if (getName().equals(INPUT_METHOD_SEGMENT.getName()))
140            return INPUT_METHOD_SEGMENT;
141    
142          throw new InvalidObjectException ("Can't resolve Attribute: " 
143                  + getName());
144        }
145        
146        /**
147         * Tests this object for equality against the specified object.
148         * The two objects will be considered equal if and only if:
149         * <ul>
150         * <li>The specified object is not <code>null</code>.
151         * <li>The specified object is an instance of 
152         * <code>AttributedCharacterIterator.Attribute</code>.
153         * <li>The specified object has the same attribute name as this object.
154         * </ul>
155         *
156         * @param obj  the <code>Object</code> to test for equality against this 
157         *             object.
158         *
159         * @return <code>true</code> if the specified object is equal to this one, 
160         *         <code>false</code> otherwise.
161         */
162        public final boolean equals(Object obj)
163        {
164          if (obj == this)
165            return true;
166          else 
167            return false;
168        }
169    
170        /**
171         * Returns a hash value for this object.
172         *
173         * @return A hash value for this object.
174         */
175        public final int hashCode()
176        {
177          return super.hashCode();
178        }
179    
180        /**
181         * Returns a <code>String</code> representation of this object.
182         *
183         * @return A <code>String</code> representation of this object.
184         */
185        public String toString()
186        {
187          return getClass().getName() + "(" + getName() + ")";
188        }
189    
190      } // Inner class Attribute
191    
192      /**
193       * Returns a list of all keys that are defined for the 
194       * text range.  This can be an empty list if no attributes are defined.
195       *
196       * @return A list of keys 
197       */
198      Set<Attribute> getAllAttributeKeys();
199    
200      /**
201       * Returns a <code>Map</code> of the attributes defined for the current 
202       * character.
203       *
204       * @return A <code>Map</code> of the attributes for the current character.
205       */
206      Map<Attribute, Object> getAttributes();
207    
208      /**
209       * Returns the value of the specified attribute for the
210       * current character.  If the attribute is not defined for the current
211       * character, <code>null</code> is returned.
212       *
213       * @param attrib The attribute to retrieve the value of.
214       *
215       * @return The value of the specified attribute
216       */
217      Object getAttribute(AttributedCharacterIterator.Attribute attrib);
218    
219      /**
220       * Returns the index of the first character in the run that
221       * contains all attributes defined for the current character.
222       *
223       * @return The start index of the run
224       */
225      int getRunStart();
226    
227      /**
228       * Returns the index of the first character in the run that
229       * contains all attributes in the specified <code>Set</code> defined for
230       * the current character.
231       *
232       * @param attribs The <code>Set</code> of attributes.
233       *
234       * @return The start index of the run.
235       */
236      int getRunStart(Set<? extends Attribute> attribs);
237      
238      /**
239       * Returns the index of the first character in the run that
240       * contains the specified attribute defined for the current character.
241       *
242       * @param attrib The attribute.
243       *
244       * @return The start index of the run.
245       */
246      int getRunStart(AttributedCharacterIterator.Attribute attrib);
247      
248      /**
249       * Returns the index of the character after the end of the run
250       * that contains all attributes defined for the current character.
251       *
252       * @return The end index of the run.
253       */
254      int getRunLimit();
255      
256      /**
257       * Returns the index of the character after the end of the run
258       * that contains all attributes in the specified <code>Set</code> defined
259       * for the current character.
260       *
261       * @param attribs The <code>Set</code> of attributes.
262       *
263       * @return The end index of the run.
264       */
265      int getRunLimit(Set<? extends Attribute> attribs);
266      
267      /**
268       * Returns the index of the character after the end of the run
269       * that contains the specified attribute defined for the current character.
270       *
271       * @param attrib The attribute.
272       * 
273       * @return The end index of the run.
274       */
275      int getRunLimit(AttributedCharacterIterator.Attribute attrib);
276    
277    } // interface AttributedCharacterIterator