/*
 * Copyright (c) 2014, peelo.net
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.peelo.enumeration;

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

/**
 * An {@link Enumeration} implementation which enumerates single object.
 */
public final class SingleElementEnumeration<E> implements Enumeration<E>
{
    /** The object to be enumerated. */
    private final E element;
    /** Whether the object has been enumerated or not. */
    private boolean enumerated;

    /**
     * Constructs new instance of {@code SingleElementEnumeration}.
     *
     * @param element The element which the new {@link Enumeration} enumerates
     */
    public SingleElementEnumeration(E element)
    {
        this.element = element;
    }

    @Override
    public boolean hasMoreElements()
    {
        return !this.enumerated;
    }

    @Override
    public E nextElement()
    {
        if (this.enumerated)
        {
            throw new NoSuchElementException();
        }
        this.enumerated = true;

        return this.element;
    }
}
