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    package net.databinder.components;
020    
021    import java.util.Collections;
022    import java.util.List;
023    
024    import org.apache.wicket.ResourceReference;
025    import org.apache.wicket.markup.html.list.ListItem;
026    
027    /** Move the given list item up in its list. */
028    public class MoveUpButton extends ListItemButton {
029            public MoveUpButton(String id, ListItem item) {
030                    super(id, item, new ResourceReference(MoveUpButton.class, "image/up-arrow.png"));
031            }
032            @Override
033            public void onSubmit() {
034                    List list = getListView().getList();
035                    int index = item.getIndex();
036                    getListView().modelChanging();
037                    Collections.swap(list, index, index - 1);
038                    getListView().modelChanged();
039            }
040            @Override
041            public boolean isEnabled() {
042                    return item.getIndex() > 0;
043            }
044    
045    }