001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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     * XYDataset.java
029     * --------------
030     * (C) Copyright 2000-2006, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: XYDataset.java,v 1.2.2.2 2006/08/03 16:22:40 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 : Renamed DataSource.java --> Dataset.java etc. (DG);
042     * 17-Nov-2001 : Now extends SeriesDataset (DG);
043     * 15-Jul-2004 : Switched getX() with getXValue() and getY() with 
044     *               getYValue() (DG);
045     * 29-Jul-2004 : Added getDomainOrder() method (DG);
046     * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
047     * 
048     */
049    
050    package org.jfree.data.xy;
051    
052    import org.jfree.data.DomainOrder;
053    import org.jfree.data.general.SeriesDataset;
054    
055    /**
056     * An interface through which data in the form of (x, y) items can be accessed.
057     */
058    public interface XYDataset extends SeriesDataset {
059    
060        /**
061         * Returns the order of the domain (or X) values returned by the dataset.
062         * 
063         * @return The order (never <code>null</code>).
064         */
065        public DomainOrder getDomainOrder();
066        
067        /**
068         * Returns the number of items in a series.
069         * <br><br>
070         * It is recommended that classes that implement this method should throw 
071         * an <code>IllegalArgumentException</code> if the <code>series</code> 
072         * argument is outside the specified range. 
073         *
074         * @param series  the series index (in the range <code>0</code> to 
075         *     <code>getSeriesCount() - 1</code>).
076         *
077         * @return The item count.
078         */
079        public int getItemCount(int series);
080    
081        /**
082         * Returns the x-value for an item within a series.  The x-values may or 
083         * may not be returned in ascending order, that is up to the class 
084         * implementing the interface.
085         *
086         * @param series  the series index (in the range <code>0</code> to 
087         *     <code>getSeriesCount() - 1</code>).
088         * @param item  the item index (in the range <code>0</code> to 
089         *     <code>getItemCount(series)</code>).
090         *
091         * @return The x-value (never <code>null</code>).
092         */
093        public Number getX(int series, int item);
094    
095        /**
096         * Returns the x-value for an item within a series.
097         * 
098         * @param series  the series index (in the range <code>0</code> to 
099         *     <code>getSeriesCount() - 1</code>).
100         * @param item  the item index (in the range <code>0</code> to 
101         *     <code>getItemCount(series)</code>).
102         * 
103         * @return The x-value.
104         */
105        public double getXValue(int series, int item);
106        
107        /**
108         * Returns the y-value for an item within a series.
109         *
110         * @param series  the series index (in the range <code>0</code> to 
111         *     <code>getSeriesCount() - 1</code>).
112         * @param item  the item index (in the range <code>0</code> to 
113         *     <code>getItemCount(series)</code>).
114         *
115         * @return The y-value (possibly <code>null</code>).
116         */
117        public Number getY(int series, int item);
118    
119        /**
120         * Returns the y-value (as a double primitive) for an item within a series.
121         * 
122         * @param series  the series index (in the range <code>0</code> to 
123         *     <code>getSeriesCount() - 1</code>).
124         * @param item  the item index (in the range <code>0</code> to 
125         *     <code>getItemCount(series)</code>).
126         * 
127         * @return The y-value.
128         */
129        public double getYValue(int series, int item);
130        
131    }