| /* |
| * Copyright (c) 2003, 2015, 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. |
| */ |
| |
| /* |
| ******************************************************************************* |
| * Copyright (C) 1996-2014, International Business Machines Corporation and * |
| * others. All Rights Reserved. * |
| ******************************************************************************* |
| */ |
| |
| 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); |
| } |
| |
| /** |
| * 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 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(); |
| |
| |
| /** |
| * Retreat to the start of the previous code point in the text, |
| * and return it (pre-decrement semantics). If the index is not |
| * preceeded by a valid surrogate pair, the behavior is the same |
| * as <code>previous()</code>. Otherwise the iterator is |
| * decremented to the start of the surrogate pair, and the code |
| * point represented by the pair is returned. |
| * @return the previous code point in the text, or DONE if the new |
| * index is before the start of the text. |
| * @stable ICU 2.4 |
| */ |
| public int previousCodePoint(){ |
| int ch1 = previous(); |
| if(UTF16.isTrailSurrogate((char)ch1)){ |
| int ch2 = previous(); |
| if(UTF16.isLeadSurrogate((char)ch2)){ |
| return UCharacterProperty.getRawSupplementary((char)ch2, |
| (char)ch1); |
| }else if (ch2 != DONE) { |
| //unmatched trail surrogate so back out |
| next(); |
| } |
| } |
| return ch1; |
| } |
| |
| /** |
| * 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); |
| |
| /** |
| * Sets the current index to the start. |
| * @stable ICU 2.4 |
| */ |
| public void setToStart() { |
| setIndex(0); |
| } |
| |
| /** |
| * 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> |
| * |
| * <pre>{@code |
| * 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> |
| * |
| * @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 IndexOutOfBoundsException 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); |
| |
| /** |
| * 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 IndexOutOfBoundsException exception if there is not enough |
| * room in the array. |
| * @stable ICU 2.4 |
| */ |
| public final int getText(char[] fillIn) { |
| return getText(fillIn, 0); |
| } |
| |
| /** |
| * Convenience method for returning the underlying text storage as a 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 points |
| * specified, either forward or backward depending on the sign of |
| * delta (positive or negative respectively). If the current index |
| * is at a trail surrogate then the first adjustment is by code |
| * unit, and the remaining adjustments are by code points. 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 delta is |
| * supplied |
| * @stable ICU 2.4 |
| * |
| */ |
| public int moveCodePointIndex(int delta){ |
| if(delta>0){ |
| while(delta>0 && nextCodePoint() != DONE){delta--;} |
| }else{ |
| while(delta<0 && previousCodePoint() != DONE){delta++;} |
| } |
| if(delta!=0){ |
| throw new IndexOutOfBoundsException(); |
| } |
| |
| return getIndex(); |
| } |
| |
| /** |
| * 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(); |
| } |
| |
| } |