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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();

};