com.ibm.icu.impl.ReplaceableUCharacterIterator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of icu4j Show documentation
Show all versions of icu4j Show documentation
International Component for Unicode for Java (ICU4J) is a mature, widely used Java library
providing Unicode and Globalization support
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 1996-2015, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.impl;
import com.ibm.icu.text.Replaceable;
import com.ibm.icu.text.ReplaceableString;
import com.ibm.icu.text.UCharacterIterator;
import com.ibm.icu.text.UTF16;
/**
* DLF docs must define behavior when Replaceable is mutated underneath
* the iterator.
*
* This and ICUCharacterIterator share some code, maybe they should share
* an implementation, or the common state and implementation should be
* moved up into UCharacterIterator.
*
* What are first, last, and getBeginIndex doing here?!?!?!
*/
public class ReplaceableUCharacterIterator extends UCharacterIterator {
// public constructor ------------------------------------------------------
/**
* Public constructor
* @param replaceable text which the iterator will be based on
*/
public ReplaceableUCharacterIterator(Replaceable replaceable){
if(replaceable==null){
throw new IllegalArgumentException();
}
this.replaceable = replaceable;
this.currentIndex = 0;
}
/**
* Public constructor
* @param str text which the iterator will be based on
*/
public ReplaceableUCharacterIterator(String str){
if(str==null){
throw new IllegalArgumentException();
}
this.replaceable = new ReplaceableString(str);
this.currentIndex = 0;
}
/**
* Public constructor
* @param buf buffer of text on which the iterator will be based
*/
public ReplaceableUCharacterIterator(StringBuffer buf){
if(buf==null){
throw new IllegalArgumentException();
}
this.replaceable = new ReplaceableString(buf);
this.currentIndex = 0;
}
// public methods ----------------------------------------------------------
/**
* Creates a copy of this iterator, does not clone the underlying
* Replaceableobject
* @return copy of this iterator
*/
@Override
public Object clone(){
try {
return super.clone();
} catch (CloneNotSupportedException e) {
return null; // never invoked
}
}
/**
* Returns the current UTF16 character.
* @return current UTF16 character
*/
@Override
public int current(){
if (currentIndex < replaceable.length()) {
return replaceable.charAt(currentIndex);
}
return DONE;
}
/**
* Returns the current codepoint
* @return current codepoint
*/
@Override
public int currentCodePoint(){
// cannot use charAt due to it different
// behaviour when index is pointing at a
// trail surrogate, check for surrogates
int ch = current();
if(UTF16.isLeadSurrogate((char)ch)){
// advance the index to get the next code point
next();
// due to post increment semantics current() after next()
// actually returns the next char which is what we want
int ch2 = current();
// current should never change the current index so back off
previous();
if(UTF16.isTrailSurrogate((char)ch2)){
// we found a surrogate pair
return Character.toCodePoint((char)ch, (char)ch2);
}
}
return ch;
}
/**
* Returns the length of the text
* @return length of the text
*/
@Override
public int getLength(){
return replaceable.length();
}
/**
* Gets the current currentIndex in text.
* @return current currentIndex in text.
*/
@Override
public int getIndex(){
return currentIndex;
}
/**
* Returns next UTF16 character and increments the iterator's currentIndex by 1.
* If the resulting currentIndex is greater or equal to the text length, the
* currentIndex is reset to the text length and a value of DONECODEPOINT is
* returned.
* @return next UTF16 character in text or DONE if the new currentIndex is off the
* end of the text range.
*/
@Override
public int next(){
if (currentIndex < replaceable.length()) {
return replaceable.charAt(currentIndex++);
}
return DONE;
}
/**
* Returns previous UTF16 character and decrements the iterator's currentIndex by
* 1.
* If the resulting currentIndex is less than 0, the currentIndex is reset to 0 and a
* value of DONECODEPOINT is returned.
* @return next UTF16 character in text or DONE if the new currentIndex is off the
* start of the text range.
*/
@Override
public int previous(){
if (currentIndex > 0) {
return replaceable.charAt(--currentIndex);
}
return DONE;
}
/**
* Sets the currentIndex to the specified currentIndex in the text and returns that
* single UTF16 character at currentIndex.
* This assumes the text is stored as 16-bit code units.
* @param currentIndex the currentIndex within the text.
* @exception IllegalArgumentException is thrown if an invalid currentIndex is
* supplied. i.e. currentIndex is out of bounds.
* @returns the character at the specified currentIndex or DONE if the specified
* currentIndex is equal to the end of the text.
*/
@Override
public void setIndex(int currentIndex) throws IndexOutOfBoundsException{
if (currentIndex < 0 || currentIndex > replaceable.length()) {
throw new IndexOutOfBoundsException();
}
this.currentIndex = currentIndex;
}
@Override
public int getText(char[] fillIn, int offset){
int length = replaceable.length();
if(offset < 0 || offset + length > fillIn.length){
throw new IndexOutOfBoundsException(Integer.toString(length));
}
replaceable.getChars(0,length,fillIn,offset);
return length;
}
// private data members ----------------------------------------------------
/**
* Replacable object
*/
private Replaceable replaceable;
/**
* Current currentIndex
*/
private int currentIndex;
}