trunk/proposal/sandbox/junit/src/main/org/apache/tools/ant/taskdefs/optional/rjunit/ArrayEnumeration.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
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 */
package org.apache.tools.ant.taskdefs.optional.rjunit;

import java.util.Enumeration;
import java.util.NoSuchElementException;

/**
 * Convenient enumeration over an array of objects.
 */
class ArrayEnumeration implements Enumeration {

    /** convenient null enumeration */
    public final static Enumeration NULL_ENUMERATION =
            new ArrayEnumeration(new Object[0]);

    /** object array */
    private Object[] array;

    /** current index */
    private int pos;

    /**
     * Initialize a new enumeration that wraps an array.
     * @param       array   the array of object to enumerate.
     */
    public ArrayEnumeration(Object[] array) {
        this.array = array;
        this.pos = 0;
    }

    /**
     * Tests if this enumeration contains more elements.
     *
     * @return  <code>true</code> if and only if this enumeration object
     *           contains at least one more element to provide;
     *          <code>false</code> otherwise.
     */
    public boolean hasMoreElements() {
        return (pos < array.length);
    }

    /**
     * Returns the next element of this enumeration if this enumeration
     * object has at least one more element to provide.
     *
     * @return     the next element of this enumeration.
     * @throws  NoSuchElementException  if no more elements exist.
     */
    public Object nextElement() throws NoSuchElementException {
        if (hasMoreElements()) {
            Object o = array[pos];
            pos++;
            return o;
        }
        throw new NoSuchElementException();
    }
}