src/com/ibm/icu/impl/ICUCharacterIterator.java

/*
 *******************************************************************************
 * Copyright (C) 1996-2000, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 *
 * $Source: /xsrl/Nsvn/icu/icu4j/src/com/ibm/icu/impl/Attic/ICUCharacterIterator.java,v $ 
 * $Date: 2002/06/20 01:18:07 $ 
 * $Revision: 1.1 $
 *
 *******************************************************************************
 */
package com.ibm.icu.impl;

import java.text.CharacterIterator;

public class ICUCharacterIterator extends UCharacterIterator {
    
    private CharacterIterator iterator;
    
    /**
     * Current index
     */
    private int currentIndex;
    
    /**
     * length
     */
    private int length;

    /**
     * cache of begin offset in character iterator
     */
    private int beginIndex;
    
    public ICUCharacterIterator(CharacterIterator iter){
        if(iter==null){
            throw new IllegalArgumentException();
        }
        iterator     = iter;
        currentIndex = 0;
	    beginIndex   = iter.getBeginIndex();
        length       = iter.getEndIndex() - beginIndex;	   
    }

    /**
     * @see UCharacterIterator#current()
     */
    public int current() {
		if (currentIndex < length) {
		    return iterator.setIndex(beginIndex + currentIndex);
		}
		return DONE;
    }

    /**
     * @see UCharacterIterator#getLength()
     */
    public int getLength() {
	    return length;
    }

    /**
     * @see UCharacterIterator#getIndex()
     */
    public int getIndex() {
	    return currentIndex;
    }

    /**
     * @see UCharacterIterator#next()
     */
    public int next() {
		if(currentIndex < length){
		    return iterator.setIndex(beginIndex + currentIndex++);
		}
		return DONE;
    }

    /**
     * @see UCharacterIterator#previous()
     */
    public int previous() {
	    if(currentIndex>0){
	        return iterator.setIndex(beginIndex + --currentIndex);
	    }
	    return DONE;
    }

    /**
     * @see UCharacterIterator#setIndex(int)
     */
    public void setIndex(int index) {
		if (index < 0 || index > length) {
		    throw new IndexOutOfBoundsException();
		}
		currentIndex = index;
    }

    /**
     * @see UCharacterIterator#setToLimit()
     */
    public void setToLimit() {
		currentIndex = length;
    }

    /**
     * @see UCharacterIterator#getText(char[])
     */
    public int getText(char[] fillIn, int offset){
        if(offset < 0 || offset + length > fillIn.length){
            throw new IndexOutOfBoundsException(Integer.toString(length));
        }
	
        for (char ch = iterator.first(); ch != iterator.DONE; ch = iterator.next()) {
	        fillIn[offset++] = ch;
	    }
	    iterator.setIndex(beginIndex + currentIndex);

        return length;
    }

    /**
     * Creates a clone of this iterator.  Clones the underlying character iterator.
     * @see UCharacterIterator#clone()
     */
    public Object clone(){
		try {
		    ICUCharacterIterator result = (ICUCharacterIterator) super.clone();
		    result.iterator = (CharacterIterator)this.iterator.clone();
		    return result;
		} catch (CloneNotSupportedException e) {      
            return null; // only invoked if bad underlying character iterator
		}
    }
    
    /**
     * @see UCharacterIterator#moveIndex()
     */
    public int moveIndex(int index){
        currentIndex += index;
        
        if(currentIndex < 0) {
	        currentIndex = 0;
		} else if(currentIndex > length) {
		    currentIndex = length;
		}
        return currentIndex;
    }
    
    /**
     * @see UCharacterIterator#getCharacterIterator()
     */
    public CharacterIterator getCharacterIterator(){
        return (CharacterIterator)iterator.clone();
    } 
}