Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * -------------- * XYDataset.java * -------------- * (C) Copyright 2000-2008, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes (from 18-Sep-2001) * -------------------------- * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG); * 15-Oct-2001 : Moved to a new package (com.jrefinery.data.*) (DG); * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG); * 17-Nov-2001 : Now extends SeriesDataset (DG); * 15-Jul-2004 : Switched getX() with getXValue() and getY() with * getYValue() (DG); * 29-Jul-2004 : Added getDomainOrder() method (DG); * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG); * */ package org.jfree.data.xy; import org.jfree.data.DomainOrder; import org.jfree.data.general.SeriesDataset; /** * An interface through which data in the form of (x, y) items can be accessed. */ public interface XYDataset extends SeriesDataset { /** * Returns the order of the domain (or X) values returned by the dataset. * * @return The order (never <code>null</code>). */ public DomainOrder getDomainOrder(); /** * Returns the number of items in a series. * <br><br> * It is recommended that classes that implement this method should throw * an <code>IllegalArgumentException</code> if the <code>series</code> * argument is outside the specified range. * * @param series the series index (in the range <code>0</code> to * <code>getSeriesCount() - 1</code>). * * @return The item count. */ public int getItemCount(int series); /** * Returns the x-value for an item within a series. The x-values may or * may not be returned in ascending order, that is up to the class * implementing the interface. * * @param series the series index (in the range <code>0</code> to * <code>getSeriesCount() - 1</code>). * @param item the item index (in the range <code>0</code> to * <code>getItemCount(series)</code>). * * @return The x-value (never <code>null</code>). */ public Number getX(int series, int item); /** * Returns the x-value for an item within a series. * * @param series the series index (in the range <code>0</code> to * <code>getSeriesCount() - 1</code>). * @param item the item index (in the range <code>0</code> to * <code>getItemCount(series)</code>). * * @return The x-value. */ public double getXValue(int series, int item); /** * Returns the y-value for an item within a series. * * @param series the series index (in the range <code>0</code> to * <code>getSeriesCount() - 1</code>). * @param item the item index (in the range <code>0</code> to * <code>getItemCount(series)</code>). * * @return The y-value (possibly <code>null</code>). */ public Number getY(int series, int item); /** * Returns the y-value (as a double primitive) for an item within a series. * * @param series the series index (in the range <code>0</code> to * <code>getSeriesCount() - 1</code>). * @param item the item index (in the range <code>0</code> to * <code>getItemCount(series)</code>). * * @return The y-value. */ public double getYValue(int series, int item); }