/*
* Copyright (c) 2000-2001 Sosnoski Software Solutions, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
package org.jibx.runtime.impl;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Iterator class for sparse values in an array. This type of iterator
* can be used for an object array which has references interspersed with
* <code>null</code>s.
*
* @author Dennis M. Sosnoski
* @version 1.1
*/
public class SparseArrayIterator implements Iterator
{
/** Array supplying values for iteration. */
protected Object[] m_array;
/** Offset of next iteration value. */
protected int m_offset;
/**
* Internal constructor.
*
* @param array array containing values to be iterated
*/
private SparseArrayIterator(Object[] array) {
m_array = array;
m_offset = -1;
advance();
}
/**
* Advance to next iteration value. This advances the current position in
* the array to the next non-<code>null</code> value.
*
* @return <code>true</code> if element available, <code>false</code> if
* not
*/
protected boolean advance() {
while (++m_offset < m_array.length) {
if (m_array[m_offset] != null) {
return true;
}
}
return false;
}
/**
* Check for iteration element available.
*
* @return <code>true</code> if element available, <code>false</code> if
* not
*/
public boolean hasNext() {
return m_offset < m_array.length;
}
/**
* Get next iteration element.
*
* @return next iteration element
* @exception NoSuchElementException if past end of iteration
*/
public Object next() {
if (m_offset < m_array.length) {
Object result = m_array[m_offset];
advance();
return result;
} else {
throw new NoSuchElementException();
}
}
/**
* Remove element from iteration. This optional operation is not supported
* and always throws an exception.
*
* @exception UnsupportedOperationException for unsupported operation
*/
public void remove() {
throw new UnsupportedOperationException();
}
/**
* Build iterator.
*
* @param array array containing values to be iterated (may be
* <code>null</code>)
* @return constructed iterator
*/
public static Iterator buildIterator(Object[] array) {
if (array == null || array.length == 0) {
return ArrayRangeIterator.EMPTY_ITERATOR;
} else {
return new SparseArrayIterator(array);
}
}
}