    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
    006     *
    007     * Project Info:  http://www.jfree.org/jfreechart/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     * PlotUtilities.java
    029     * ------------------
    030     * (C) Copyright 2007, 2008, by Sergei Ivanov and Contributors.
    031     *
    032     * Original Author:  Sergei Ivanov;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * Changes
    036     * -------
    037     * 26-Sep-2007 : Version 1, contributed by Sergei Ivanov (see patch
    038     *               1772932) (DG);
    039     *
    040     */
    041
    042    package org.jfree.chart.plot;
    043
    044    import org.jfree.data.general.DatasetUtilities;
    045    import org.jfree.data.xy.XYDataset;
    046
    047    /**
    048     * Some utility methods related to the plot classes.
    049     *
    050     * @since 1.0.7
    051     */
    052    public class PlotUtilities {
    053
    054        /**
    055         * Returns <code>true</code> if all the datasets belonging to the specified
    056         * plot are empty or <code>null</code>, and <code>false</code> otherwise.
    057         *
    058         * @param plot  the plot (<code>null</code> permitted).
    059         *
    060         * @return A boolean.
    061         *
    062         * @since 1.0.7
    063         */
    064        public static boolean isEmptyOrNull(XYPlot plot) {
    065            if (plot != null) {
    066                for (int i = 0, n = plot.getDatasetCount(); i < n; i++) {
    067                    final XYDataset dataset = plot.getDataset(i);
    068                    if (!DatasetUtilities.isEmptyOrNull(dataset)) {
    069                        return false;
    070                    }
    071                }
    072            }
    073            return true;
    074        }
    075
    076    }