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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 1996-2010, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.impl;
import java.text.CharacterIterator;
import com.ibm.icu.text.UCharacterIterator;
/**
* This class is a wrapper around UCharacterIterator and implements the
* CharacterIterator protocol
* @author ram
*/
public class UCharacterIteratorWrapper implements CharacterIterator{
public UCharacterIteratorWrapper(UCharacterIterator iter){
this.iterator = iter;
}
private UCharacterIterator iterator;
/**
* Sets the position to getBeginIndex() and returns the character at that
* position.
* @return the first character in the text, or DONE if the text is empty
* @see #getBeginIndex()
*/
@Override
public char first(){
//UCharacterIterator always iterates from 0 to length
iterator.setToStart();
return (char)iterator.current();
}
/**
* Sets the position to getEndIndex()-1 (getEndIndex() if the text is empty)
* and returns the character at that position.
* @return the last character in the text, or DONE if the text is empty
* @see #getEndIndex()
*/
@Override
public char last(){
iterator.setToLimit();
return (char)iterator.previous();
}
/**
* Gets the character at the current position (as returned by getIndex()).
* @return the character at the current position or DONE if the current
* position is off the end of the text.
* @see #getIndex()
*/
@Override
public char current(){
return (char) iterator.current();
}
/**
* Increments the iterator's index by one and returns the character
* at the new index. If the resulting index is greater or equal
* to getEndIndex(), the current index is reset to getEndIndex() and
* a value of DONE is returned.
* @return the character at the new position or DONE if the new
* position is off the end of the text range.
*/
@Override
public char next(){
//pre-increment
iterator.next();
return (char) iterator.current();
}
/**
* Decrements the iterator's index by one and returns the character
* at the new index. If the current index is getBeginIndex(), the index
* remains at getBeginIndex() and a value of DONE is returned.
* @return the character at the new position or DONE if the current
* position is equal to getBeginIndex().
*/
@Override
public char previous(){
//pre-decrement
return (char) iterator.previous();
}
/**
* Sets the position to the specified position in the text and returns that
* character.
* @param position the position within the text. Valid values range from
* getBeginIndex() to getEndIndex(). An IllegalArgumentException is thrown
* if an invalid value is supplied.
* @return the character at the specified position or DONE if the specified position is equal to getEndIndex()
*/
@Override
public char setIndex(int position){
iterator.setIndex(position);
return (char) iterator.current();
}
/**
* Returns the start index of the text.
* @return the index at which the text begins.
*/
@Override
public int getBeginIndex(){
//UCharacterIterator always starts from 0
return 0;
}
/**
* Returns the end index of the text. This index is the index of the first
* character following the end of the text.
* @return the index after the last character in the text
*/
@Override
public int getEndIndex(){
return iterator.getLength();
}
/**
* Returns the current index.
* @return the current index.
*/
@Override
public int getIndex(){
return iterator.getIndex();
}
/**
* Create a copy of this iterator
* @return A copy of this
*/
@Override
public Object clone(){
try {
UCharacterIteratorWrapper result = (UCharacterIteratorWrapper) super.clone();
result.iterator = (UCharacterIterator)this.iterator.clone();
return result;
} catch (CloneNotSupportedException e) {
return null; // only invoked if bad underlying character iterator
}
}
}