/*
 * Copyright (c) 2006 Henri Sivonen
 *
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 */

package nu.validator.checker.table;

import java.util.Comparator;

/**
 * Compares cells using their <code>left</code> field. The cells can never be equal.
 * 
 * @version $Id$
 * @author hsivonen
 */
final class HorizontalCellComparator implements Comparator<Cell> {

    public static final HorizontalCellComparator THE_INSTANCE = new HorizontalCellComparator();
    
    private HorizontalCellComparator() {
        super();
    }

    @Override
    public int compare(Cell cell0, Cell cell1) {
        if (cell0.getLeft() < cell1.getLeft()) {
            return -1;
        } else if (cell0.getLeft() > cell1.getLeft()) {
            return 1;
        } else {
            throw new IllegalStateException("Two cells in effect cannot start on the same column, so this should never happen!");
        }
    }

}
