/*------------------------------------------------------------------------
 *  SymbolIterator
 *
 *  Copyright 2007-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
 *
 *  This file is part of the ZBar Bar Code Reader.
 *
 *  The ZBar Bar Code Reader is free software; you can redistribute it
 *  and/or modify it under the terms of the GNU Lesser Public License as
 *  published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  The ZBar Bar Code Reader 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 Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser Public License
 *  along with the ZBar Bar Code Reader; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA  02110-1301  USA
 *
 *  http://sourceforge.net/projects/zbar
 *------------------------------------------------------------------------*/

package net.sourceforge.zbar;

/** Iterator over a SymbolSet.
 */
public class SymbolIterator
    implements java.util.Iterator<Symbol>
{
    /** Next symbol to be returned by the iterator. */
    private Symbol current;

    /** SymbolIterators are only created by internal interface methods. */
    SymbolIterator (Symbol first)
    {
        current = first;
    }

    /** Returns true if the iteration has more elements. */
    public boolean hasNext ()
    {
        return(current != null);
    }

    /** Retrieves the next element in the iteration. */
    public Symbol next ()
    {
        if(current == null)
            throw(new java.util.NoSuchElementException
                  ("access past end of SymbolIterator"));

        Symbol result = current;
        long sym = current.next();
        if(sym != 0)
            current = new Symbol(sym);
        else
            current = null;
        return(result);
    }

    /** Raises UnsupportedOperationException. */
    public void remove ()
    {
        throw(new UnsupportedOperationException
              ("SymbolIterator is immutable"));
    }
}