    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}