    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    025 * Other names may be trademarks of their respective owners.]
    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
    042package org.jfree.chart.plot;
    043
    044import org.jfree.data.general.DatasetUtilities;
    045import org.jfree.data.xy.XYDataset;
    046
    047/**
    048 * Some utility methods related to the plot classes.
    049 *
    050 * @since 1.0.7
    051 */
    052public 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}