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/*******************************************************************************
 * Copyright (c) 2016 Association Cénotélie (cenotelie.fr)
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this program.
 * If not, see .
 ******************************************************************************/

package fr.cenotelie.commons.utils.collections;

import java.util.Iterator;

/**
 * Represents an iterator that concatenates other iterators
 *
 * @param  The type of elements to iterator over
 * @author Laurent Wouters
 */
public class ConcatenatedIterator implements Iterator {
    /**
     * The inner iterators
     */
    protected final Iterator[] content;
    /**
     * The index of the current iterator
     */
    protected int index;
    /**
     * The iterator of the current result
     */
    protected Iterator currentIterator;

    /**
     * Initializes this iterator
     *
     * @param content The inner iterators
     */
    public ConcatenatedIterator(Iterator[] content) {
        this.content = content;
        this.index = 0;
        while (index != content.length && !content[index].hasNext())
            index++;
    }

    @Override
    public boolean hasNext() {
        return (index != content.length && content[index].hasNext());
    }

    @Override
    public T next() {
        T result = content[index].next();
        currentIterator = content[index];
        while (index != content.length && !content[index].hasNext())
            index++;
        return result;
    }

    @Override
    public void remove() {
        currentIterator.remove();
    }
}