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/* * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved. * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ /* ******************************************************************************* * (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved                     * *                                                                             * * The original version of this source code and documentation is copyrighted   * * and owned by IBM, These materials are provided under terms of a License     * * Agreement between IBM and Sun. This technology is protected by multiple     * * US and International patents. This notice and attribution to IBM may not    * * to removed.                                                                 * ******************************************************************************* */ package sun.text.normalizer; import java.text.CharacterIterator; /** * Abstract class that defines an API for iteration on text objects.This is an * interface for forward and backward iteration and random access into a text * object. Forward iteration is done with post-increment and backward iteration * is done with pre-decrement semantics, while the * <code>java.text.CharacterIterator</code> interface methods provided forward * iteration with "pre-increment" and backward iteration with pre-decrement * semantics. This API is more efficient for forward iteration over code points. * The other major difference is that this API can do both code unit and code point * iteration, <code>java.text.CharacterIterator</code> can only iterate over * code units and is limited to BMP (0 - 0xFFFF) * @author Ram * @stable ICU 2.4 */public abstract class UCharacterIterator                      implements Cloneable {     /**     * Protected default constructor for the subclasses     * @stable ICU 2.4     */    protected UCharacterIterator(){    }     /**     * Indicator that we have reached the ends of the UTF16 text.     * Moved from UForwardCharacterIterator.java     * @stable ICU 2.4     */    public static final int DONE = -1;     // static final methods ----------------------------------------------------     /**     * Returns a <code>UCharacterIterator</code> object given a     * source string.     * @param source a string     * @return UCharacterIterator object     * @exception IllegalArgumentException if the argument is null     * @stable ICU 2.4     */    public static final UCharacterIterator getInstance(String source){        return new ReplaceableUCharacterIterator(source);    }     //// for StringPrep    /**     * Returns a <code>UCharacterIterator</code> object given a     * source StringBuffer.     * @param source an string buffer of UTF-16 code units     * @return UCharacterIterator object     * @exception IllegalArgumentException if the argument is null     * @stable ICU 2.4     */    public static final UCharacterIterator getInstance(StringBuffer source){        return new ReplaceableUCharacterIterator(source);    }     /**     * Returns a <code>UCharacterIterator</code> object given a     * CharacterIterator.     * @param source a valid CharacterIterator object.     * @return UCharacterIterator object     * @exception IllegalArgumentException if the argument is null     * @stable ICU 2.4     */    public static final UCharacterIterator getInstance(CharacterIterator source){        return new CharacterIteratorWrapper(source);    }     // public methods ----------------------------------------------------------     /**     * Returns the code unit at the current index.  If index is out     * of range, returns DONE.  Index is not changed.     * @return current code unit     * @stable ICU 2.4     */    public abstract int current();     /**     * Returns the length of the text     * @return length of the text     * @stable ICU 2.4     */    public abstract int getLength();      /**     * Gets the current index in text.     * @return current index in text.     * @stable ICU 2.4     */    public abstract int getIndex();      /**     * Returns the UTF16 code unit at index, and increments to the next     * code unit (post-increment semantics).  If index is out of     * range, DONE is returned, and the iterator is reset to the limit     * of the text.     * @return the next UTF16 code unit, or DONE if the index is at the limit     *         of the text.     * @stable ICU 2.4     */    public abstract int next();     /**     * Returns the code point at index, and increments to the next code     * point (post-increment semantics).  If index does not point to a     * valid surrogate pair, the behavior is the same as     * <code>next()</code>.  Otherwise the iterator is incremented past     * the surrogate pair, and the code point represented by the pair     * is returned.     * @return the next codepoint in text, or DONE if the index is at     *         the limit of the text.     * @stable ICU 2.4     */    public int nextCodePoint(){        int ch1 = next();        if(UTF16.isLeadSurrogate((char)ch1)){            int ch2 = next();            if(UTF16.isTrailSurrogate((char)ch2)){                return UCharacterProperty.getRawSupplementary((char)ch1,                                                              (char)ch2);            }else if (ch2 != DONE) {                // unmatched surrogate so back out                previous();            }        }        return ch1;    }     /**     * Decrement to the position of the previous code unit in the     * text, and return it (pre-decrement semantics).  If the     * resulting index is less than 0, the index is reset to 0 and     * DONE is returned.     * @return the previous code unit in the text, or DONE if the new     *         index is before the start of the text.     * @stable ICU 2.4     */    public abstract int previous();     /**     * Sets the index to the specified index in the text.     * @param index the index within the text.     * @exception IndexOutOfBoundsException is thrown if an invalid index is     *            supplied     * @stable ICU 2.4     */    public abstract void setIndex(int index);     //// for StringPrep    /**     * Fills the buffer with the underlying text storage of the iterator     * If the buffer capacity is not enough a exception is thrown. The capacity     * of the fill in buffer should at least be equal to length of text in the     * iterator obtained by calling <code>getLength()</code>.     * <b>Usage:</b>     *     * <code>     * <pre>     *         UChacterIterator iter = new UCharacterIterator.getInstance(text);     *         char[] buf = new char[iter.getLength()];     *         iter.getText(buf);     *     *         OR     *         char[] buf= new char[1];     *         int len = 0;     *         for(;;){     *             try{     *                 len = iter.getText(buf);     *                 break;     *             }catch(IndexOutOfBoundsException e){     *                 buf = new char[iter.getLength()];     *             }     *         }     * </pre>     * </code>     *     * @param fillIn an array of chars to fill with the underlying UTF-16 code     *         units.     * @param offset the position within the array to start putting the data.     * @return the number of code units added to fillIn, as a convenience     * @exception IndexOutOfBounds exception if there is not enough     *            room after offset in the array, or if offset < 0.     * @stable ICU 2.4     */    public abstract int getText(char[] fillIn, int offset);     //// for StringPrep    /**     * Convenience override for <code>getText(char[], int)</code> that provides     * an offset of 0.     * @param fillIn an array of chars to fill with the underlying UTF-16 code     *         units.     * @return the number of code units added to fillIn, as a convenience     * @exception IndexOutOfBounds exception if there is not enough     *            room in the array.     * @stable ICU 2.4     */    public final int getText(char[] fillIn) {        return getText(fillIn, 0);    }     //// for StringPrep    /**     * Convenience method for returning the underlying text storage as as string     * @return the underlying text storage in the iterator as a string     * @stable ICU 2.4     */    public String getText() {        char[] text = new char[getLength()];        getText(text);        return new String(text);    }     /**     * Moves the current position by the number of code units     * specified, either forward or backward depending on the sign     * of delta (positive or negative respectively).  If the resulting     * index would be less than zero, the index is set to zero, and if     * the resulting index would be greater than limit, the index is     * set to limit.     *     * @param delta the number of code units to move the current     *              index.     * @return the new index.     * @exception IndexOutOfBoundsException is thrown if an invalid index is     *            supplied     * @stable ICU 2.4     *     */    public int moveIndex(int delta) {        int x = Math.max(0, Math.min(getIndex() + delta, getLength()));        setIndex(x);        return x;    }     /**     * Creates a copy of this iterator, independent from other iterators.     * If it is not possible to clone the iterator, returns null.     * @return copy of this iterator     * @stable ICU 2.4     */    public Object clone() throws CloneNotSupportedException{        return super.clone();    } }