/* * 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 * java.text.CharacterIterator 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, java.text.CharacterIterator 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 UCharacterIterator 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 UCharacterIterator 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 UCharacterIterator 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 * next(). 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 getLength(). * Usage: * * *
     *         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()];
     *             }
     *         }
     * 
*
* * @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 getText(char[], int) 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(); } }