001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * Dataset.java
029 * ------------
030 * (C) Copyright 2000-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.general;
038
039/**
040 * The base interface for data sets.
041 * <P>
042 * All datasets are required to support the {@link DatasetChangeEvent}
043 * mechanism by allowing listeners to register and receive notification of any
044 * changes to the dataset.
045 * <P>
046 * In addition, all datasets must belong to one (and only one)
047 * {@link DatasetGroup}.  The group object maintains a reader-writer lock
048 * which provides synchronised access to the datasets in multi-threaded code.
049 */
050public interface Dataset {
051
052    /**
053     * Registers an object for notification of changes to the dataset.
054     *
055     * @param listener  the object to register.
056     */
057    void addChangeListener(DatasetChangeListener listener);
058
059    /**
060     * Deregisters an object for notification of changes to the dataset.
061     *
062     * @param listener  the object to deregister.
063     */
064    void removeChangeListener(DatasetChangeListener listener);
065
066    /**
067     * Returns the dataset group.
068     *
069     * @return The dataset group.
070     */
071    DatasetGroup getGroup();
072
073    /**
074     * Sets the dataset group.
075     *
076     * @param group  the dataset group.
077     */
078    void setGroup(DatasetGroup group);
079
080}