001    /*
002     * Databinder: a simple bridge from Wicket to Hibernate
003     * Copyright (C) 2006  Nathan Hamblen nathan@technically.us
004    
005     * This library is free software; you can redistribute it and/or
006     * modify it under the terms of the GNU Lesser General Public
007     * License as published by the Free Software Foundation; either
008     * version 2.1 of the License, or (at your option) any later version.
009     *
010     * This library is distributed in the hope that it will be useful,
011     * but WITHOUT ANY WARRANTY; without even the implied warranty of
012     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013     * Lesser General Public License for more details.
014     *
015     * You should have received a copy of the GNU Lesser General Public
016     * License along with this library; if not, write to the Free Software
017     * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
018     */
019    
020    package net.databinder.components;
021    
022    import org.apache.wicket.AttributeModifier;
023    import org.apache.wicket.markup.html.list.ListItem;
024    import org.apache.wicket.model.AbstractReadOnlyModel;
025    
026    /**
027     * Alternates between class attribute values of "a" and "b", or user selected
028     * values, for even and odd ListItem components.
029     * @author Nathan Hamblen
030     */
031    public class AlternatingClassModifier extends AttributeModifier {
032            /**
033             * Constructs AttributeModifier for "class" with values "a" or "b".
034             * @param item Object whose index determines class value.
035             */
036            public AlternatingClassModifier(final ListItem item) {
037                    this(item, "a", "b");
038            }
039    
040            /**
041             * Constructs AttributeModifier for "class" with the given alternating class values.
042             * @param item Object whose index determines class value.
043             */
044            public AlternatingClassModifier(final ListItem item, final String classA, final String classB) {
045                    super("class", true, new AbstractReadOnlyModel() {
046                            @Override
047                            public Object getObject() {
048                                    return item.getIndex() % 2 == 0 ? classA : classB;
049                            }
050                    });
051            }
052    }