001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2007, 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     * AbstractXYDataset.java
029     * ----------------------
030     * (C) Copyright 2004-2007, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited).
033     * Contributor(s):   -;
034     *
035     * Changes
036     * -------
037     * 05-May-2004 : Version 1 (DG);
038     * 15-Jul-2004 : Switched getX() with getXValue() and getY() with 
039     *               getYValue() (DG);
040     * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
041     * 
042     */
043    
044    package org.jfree.data.xy;
045    
046    import org.jfree.data.DomainOrder;
047    import org.jfree.data.general.AbstractSeriesDataset;
048    
049    /**
050     * An base class that you can use to create new implementations of the 
051     * {@link XYDataset} interface.
052     */
053    public abstract class AbstractXYDataset extends AbstractSeriesDataset 
054                                            implements XYDataset {
055    
056        /**
057         * Returns the order of the domain (X) values.
058         * 
059         * @return The domain order.
060         */
061        public DomainOrder getDomainOrder() {
062            return DomainOrder.NONE;
063        }
064        
065        /**
066         * Returns the x-value (as a double primitive) for an item within a series.
067         * 
068         * @param series  the series index (zero-based).
069         * @param item  the item index (zero-based).
070         * 
071         * @return The value.
072         */
073        public double getXValue(int series, int item) {
074            double result = Double.NaN;
075            Number x = getX(series, item);
076            if (x != null) {
077                result = x.doubleValue();   
078            }
079            return result;   
080        }
081    
082        /**
083         * Returns the y-value (as a double primitive) for an item within a series.
084         * 
085         * @param series  the series index (zero-based).
086         * @param item  the item index (zero-based).
087         * 
088         * @return The value.
089         */
090        public double getYValue(int series, int item) {
091            double result = Double.NaN;
092            Number y = getY(series, item);
093            if (y != null) {
094                result = y.doubleValue();   
095            }
096            return result;   
097        }
098    
099    }