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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 package java.text;

 import java.io.InvalidObjectException;

 import java.io.Serializable;

 import java.util.HashMap;

 import java.util.Map;

 import java.util.Set;

 /**

  * An {@code AttributedCharacterIterator} allows iteration through both text and

  * related attribute information.

  *

  * <p>

  * An attribute is a key/value pair, identified by the key.  No two

  * attributes on a given character can have the same key.

  *

  * <p>The values for an attribute are immutable, or must not be mutated

  * by clients or storage.  They are always passed by reference, and not

  * cloned.

  *

  * <p>A <em>run with respect to an attribute</em> is a maximum text range for

  * which:

  * <ul>

  * <li>the attribute is undefined or {@code null} for the entire range, or

  * <li>the attribute value is defined and has the same non-{@code null} value for the

  *     entire range.

  * </ul>

  *

  * <p>A <em>run with respect to a set of attributes</em> is a maximum text range for

  * which this condition is met for each member attribute.

  *

  * <p>When getting a run with no explicit attributes specified (i.e.,

  * calling {@link #getRunStart()} and {@link #getRunLimit()}), any

  * contiguous text segments having the same attributes (the same set

  * of attribute/value pairs) are treated as separate runs if the

  * attributes have been given to those text segments separately.

  *

  * <p>The returned indexes are limited to the range of the iterator.

  *

  * <p>The returned attribute information is limited to runs that contain

  * the current character.

  *

  * <p>

  * Attribute keys are instances of {@link AttributedCharacterIterator.Attribute} and its

  * subclasses, such as {@link java.awt.font.TextAttribute}.

  *

  * @see AttributedCharacterIterator.Attribute

  * @see java.awt.font.TextAttribute

  * @see AttributedString

  * @see Annotation

  * @since 1.2

  */

 public interface AttributedCharacterIterator extends CharacterIterator {

     /**

      * Defines attribute keys that are used to identify text attributes. These

      * keys are used in {@code AttributedCharacterIterator} and {@code AttributedString}.

      * @see AttributedCharacterIterator

      * @see AttributedString

      * @since 1.2

      */

     public static class Attribute implements Serializable {

         /**

          * The name of this {@code Attribute}. The name is used primarily by {@code readResolve}

          * to look up the corresponding predefined instance when deserializing

          * an instance.

          * @serial

          */

         private String name;

         // table of all instances in this class, used by readResolve

         private static final Map instanceMap = new HashMap(7);

         /**

          * Constructs an {@code Attribute} with the given name.

          */

         protected Attribute(String name) {

             this.name = name;

             if (this.getClass() == Attribute.class) {

                 instanceMap.put(name, this);

             }

         }

         /**

          * Compares two objects for equality. This version only returns true

          * for <code>x.equals(y)</code> if <code>x</code> and <code>y</code> refer

          * to the same object, and guarantees this for all subclasses.

          */

         public final boolean equals(Object obj) {

             return super.equals(obj);

         }

         /**

          * Returns a hash code value for the object. This version is identical to

          * the one in {@code Object}, but is also final.

          */

         public final int hashCode() {

             return super.hashCode();

         }

         /**

          * Returns a string representation of the object. This version returns the

          * concatenation of class name, {@code "("}, a name identifying the attribute

          * and {@code ")"}.

          */

         public String toString() {

             return getClass().getName() + "(" + name + ")";

         }

         /**

          * Returns the name of the attribute.

          */

         protected String getName() {

             return name;

         }

         /**

          * Resolves instances being deserialized to the predefined constants.

          */

         protected Object readResolve() throws InvalidObjectException {

             if (this.getClass() != Attribute.class) {

                 throw new InvalidObjectException("subclass didn't correctly implement readResolve");

             }

             Attribute instance = (Attribute) instanceMap.get(getName());

             if (instance != null) {

                 return instance;

             } else {

                 throw new InvalidObjectException("unknown attribute name");

             }

         }

         /**

          * Attribute key for the language of some text.

          * <p> Values are instances of {@link java.util.Locale Locale}.

          * @see java.util.Locale

          */

         public static final Attribute LANGUAGE = new Attribute("language");

         /**

          * Attribute key for the reading of some text. In languages where the written form

          * and the pronunciation of a word are only loosely related (such as Japanese),

          * it is often necessary to store the reading (pronunciation) along with the

          * written form.

          * <p>Values are instances of {@link Annotation} holding instances of {@link String}.

          * @see Annotation

          * @see java.lang.String

          */

         public static final Attribute READING = new Attribute("reading");

         /**

          * Attribute key for input method segments. Input methods often break

          * up text into segments, which usually correspond to words.

          * <p>Values are instances of {@link Annotation} holding a {@code null} reference.

          * @see Annotation

          */

         public static final Attribute INPUT_METHOD_SEGMENT = new Attribute("input_method_segment");

         // make sure the serial version doesn't change between compiler versions

         private static final long serialVersionUID = -9142742483513960612L;

     };

     /**

      * Returns the index of the first character of the run

      * with respect to all attributes containing the current character.

      *

      * <p>Any contiguous text segments having the same attributes (the

      * same set of attribute/value pairs) are treated as separate runs

      * if the attributes have been given to those text segments separately.

      */

     public int getRunStart();

     /**

      * Returns the index of the first character of the run

      * with respect to the given {@code attribute} containing the current character.

      */

     public int getRunStart(Attribute attribute);

     /**

      * Returns the index of the first character of the run

      * with respect to the given {@code attributes} containing the current character.

      */

     public int getRunStart(Set<? extends Attribute> attributes);

     /**

      * Returns the index of the first character following the run

      * with respect to all attributes containing the current character.

      *

      * <p>Any contiguous text segments having the same attributes (the

      * same set of attribute/value pairs) are treated as separate runs

      * if the attributes have been given to those text segments separately.

      */

     public int getRunLimit();

     /**

      * Returns the index of the first character following the run

      * with respect to the given {@code attribute} containing the current character.

      */

     public int getRunLimit(Attribute attribute);

     /**

      * Returns the index of the first character following the run

      * with respect to the given {@code attributes} containing the current character.

      */

     public int getRunLimit(Set<? extends Attribute> attributes);

     /**

      * Returns a map with the attributes defined on the current

      * character.

      */

     public Map<Attribute,Object> getAttributes();

     /**

      * Returns the value of the named {@code attribute} for the current character.

      * Returns {@code null} if the {@code attribute} is not defined.

      */

     public Object getAttribute(Attribute attribute);

     /**

      * Returns the keys of all attributes defined on the

      * iterator's text range. The set is empty if no

      * attributes are defined.

      */

     public Set<Attribute> getAllAttributeKeys();

 };