001/* ========================================================================
002 * JCommon : a free general purpose class library for the Java(tm) platform
003 * ========================================================================
004 *
005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jcommon/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -----------------------
028 * SortableTableModel.java
029 * -----------------------
030 * (C) Copyright 2000-2005, by Object Refinery Limited;
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * $Id: SortableTableModel.java,v 1.6 2008/09/10 09:26:11 mungady Exp $
036 *
037 * Changes (from 26-Oct-2001)
038 * --------------------------
039 * 26-Oct-2001 : Changed package to com.jrefinery.ui.* (DG);
040 * 20-Nov-2001 : Made constructor protected (DG);
041 * 14-Oct-2002 : Fixed errors reported by Checkstyle (DG);
042 *
043 */
044
045package org.jfree.ui;
046
047import javax.swing.table.AbstractTableModel;
048
049/**
050 * The base class for a sortable table model.
051 *
052 * @author David Gilbert
053 */
054public abstract class SortableTableModel extends AbstractTableModel {
055
056    /** The column on which the data is sorted (-1 for no sorting). */
057    private int sortingColumn;
058
059    /** Indicates ascending (true) or descending (false) order. */
060    private boolean ascending;
061
062    /**
063     * Constructs a sortable table model.
064     */
065    public SortableTableModel() {
066        this.sortingColumn = -1;
067        this.ascending = true;
068    }
069
070    /**
071     * Returns the index of the sorting column, or -1 if the data is not sorted
072     * on any column.
073     *
074     * @return the column used for sorting.
075     */
076    public int getSortingColumn() {
077        return this.sortingColumn;
078    }
079
080    /**
081     * Returns <code>true</code> if the data is sorted in ascending order, and
082     * <code>false</code> otherwise.
083     *
084     * @return <code>true</code> if the data is sorted in ascending order, and
085     *         <code>false</code> otherwise.
086     */
087    public boolean isAscending() {
088        return this.ascending;
089    }
090
091    /**
092     * Sets the flag that determines whether the sort order is ascending or
093     * descending.
094     *
095     * @param flag  the flag.
096     */
097    public void setAscending(final boolean flag) {
098        this.ascending = flag;
099    }
100
101    /**
102     * Sorts the table.
103     *
104     * @param column  the column to sort on (zero-based index).
105     * @param ascending  a flag to indicate ascending order or descending order.
106     */
107    public void sortByColumn(final int column, final boolean ascending) {
108        if (isSortable(column)) {
109            this.sortingColumn = column;
110        }
111    }
112
113    /**
114     * Returns a flag indicating whether or not a column is sortable.
115     *
116     * @param column  the column (zero-based index).
117     *
118     * @return boolean.
119     */
120    public boolean isSortable(final int column) {
121        return false;
122    }
123
124}