001/*
002 * Copyright (c) 2005 Peter Palotas, Fredrik Johansson, Einar Pehrson,
003 * Sebastian Kekkonen, Lars Magnus Lang, Malin Johansson and Sofia Nilsson
004 *
005 * This file is part of
006 * CleanSheets Extension for Assertions
007 *
008 * CleanSheets Extension for Assertions is free software; you can
009 * redistribute it and/or modify it under the terms of the GNU General Public
010 * License as published by the Free Software Foundation; either version 2 of
011 * the License, or (at your option) any later version.
012 *
013 * CleanSheets Extension for Assertions is distributed in the hope that
014 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
015 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with CleanSheets Extension for Assertions; if not, write to the
020 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
021 * Boston, MA  02111-1307  USA
022 */
023package csheets.ext.assertion;
024
025import java.util.Iterator;
026import java.util.NoSuchElementException;
027
028/** An iterator wrapper used by MultiInterval to be able to expose
029    the intervals contained in the MultiInterval without
030    allowing the user to modify the underlying collection
031    directly.
032    @author Peter Palotas */
033public class ConstMultiIntervalIterator implements Iterator<Interval> {
034
035        private Iterator<Interval> iter;
036
037        /** Creates a new "const"-iterator using the iterator specified
038            for all operations except remove.
039            @param iter the iterator to use for iteration. */
040        protected ConstMultiIntervalIterator(Iterator<Interval> iter) {
041                this.iter = iter;
042        }
043
044        /** Returns <code>true</code> if the iteration has more elements.
045                (In other words, returns <code>true</code> if <code>next</code> would return
046                an element rather than throwing an exception.)
047                @return true if the iterator has more elements, <code>false</code> otherwise. */
048        public boolean hasNext() {
049                return iter.hasNext();
050        }
051
052        /** Returns the next element in the iteration. Calling this method repeatedly until the
053                <code>hasNext()</code> method returns <code>false</code> will return each element
054                in the underlying collection exactly once.
055                @return the next element in the iteration.
056                @exception NoSuchElementException iteration has no more elements. */
057        public Interval next() {
058                return iter.next();
059        }
060
061        /** Throws UnsupportedOperationException since this iterator does not allow modification
062                of the unerlying collection.
063                @exception UnsupportedOperationException whenever called. */
064        public void remove() {
065                throw new UnsupportedOperationException("Cannot modify a MultiInterval through its iterator");
066        }
067};