    001    /* ===========================================================
    002     * JFreeChart : a free chart 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/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     * Dataset.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: Dataset.java,v 1.3.2.1 2005/10/25 21:32:29 mungady Exp $
    036     *
    037     * Changes (from 18-Sep-2001)
    038     * --------------------------
    039     * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG);
    040     * 15-Oct-2001 : Moved to a new package (com.jrefinery.data.*) (DG);
    041     * 22-Oct-2001 : Changed name to Dataset.java (DG);
    042     * 17-Nov-2001 : Added getLegendItemCount() and getLegendItemLabels() methods,
    043     *               created SeriesDataset interface and transferred series related
    044     *               methods out (DG);
    045     * 22-Jan-2002 : Reconsidered (and removed) the getLegendItemCount() and
    046     *               getLegendItemLabels() methods...leave this to client code (DG);
    047     * 27-Sep-2002 : Added get/setDatasetGroup() methods (DG);
    048     * 10-Jan-2003 : Updated Javadocs (DG);
    049     *
    050     */
    051
    052    package org.jfree.data.general;
    053
    054    /**
    055     * The base interface for data sets.
    056     * <P>
    057     * All datasets are required to support the {@link DatasetChangeEvent}
    058     * mechanism by allowing listeners to register and receive notification of any
    059     * changes to the dataset.
    060     * <P>
    061     * In addition, all datasets must belong to one (and only one)
    062     * {@link DatasetGroup}.  The group object maintains a reader-writer lock
    063     * which provides synchronised access to the datasets in multi-threaded code.
    064     */
    065    public interface Dataset {
    066
    067        /**
    068         * Registers an object for notification of changes to the dataset.
    069         *
    070         * @param listener  the object to register.
    071         */
    072        public void addChangeListener(DatasetChangeListener listener);
    073
    074        /**
    075         * Deregisters an object for notification of changes to the dataset.
    076         *
    077         * @param listener  the object to deregister.
    078         */
    079        public void removeChangeListener(DatasetChangeListener listener);
    080
    081        /**
    082         * Returns the dataset group.
    083         *
    084         * @return The dataset group.
    085         */
    086        public DatasetGroup getGroup();
    087
    088        /**
    089         * Sets the dataset group.
    090         *
    091         * @param group  the dataset group.
    092         */
    093        public void setGroup(DatasetGroup group);
    094
    095    }