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.] * * --------------------------------- * AbstractXYItemLabelGenerator.java * --------------------------------- * (C) Copyright 2004-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 27-Feb-2004 : Version 1 (DG); * 12-May-2004 : Moved default tool tip format to * StandardXYToolTipGenerator (DG); * 15-Jul-2004 : Switched getX() with getXValue() and getY() with * getYValue() (DG); * 08-Oct-2004 : Modified createItemArray() method to handle null values (DG); * 10-Jan-2005 : Updated createItemArray() to use x, y primitives if * possible (DG); * ------------- JFREECHART 1.0.x -------------------------------------------- * 26-Jan-2006 : Minor API doc update (DG); * 25-Jan-2007 : Added new constructor and fixed bug in clone() method (DG); * 16-Oct-2007 : Removed redundant code (DG); * 23-Nov-2007 : Implemented hashCode() (DG); * 26-May-2008 : Added accessor methods for nullYString and updated equals() * method (DG); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.chart.labels; import java.io.Serializable; import java.text.DateFormat; import java.text.MessageFormat; import java.text.NumberFormat; import java.util.Date; import org.jfree.chart.HashUtilities; import org.jfree.chart.util.ParamChecks; import org.jfree.data.xy.XYDataset; import org.jfree.util.ObjectUtilities; /** * A base class for creating item label generators. */ public class AbstractXYItemLabelGenerator implements Cloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = 5869744396278660636L; /** The item label format string. */ private String formatString; /** A number formatter for the x value. */ private NumberFormat xFormat; /** A date formatter for the x value. */ private DateFormat xDateFormat; /** A formatter for the y value. */ private NumberFormat yFormat; /** A date formatter for the y value. */ private DateFormat yDateFormat; /** The string used to represent 'null' for the y-value. */ private String nullYString = "null"; /** * Creates an item label generator using default number formatters. */ protected AbstractXYItemLabelGenerator() { this("{2}", NumberFormat.getNumberInstance(), NumberFormat.getNumberInstance()); } /** * Creates an item label generator using the specified number formatters. * * @param formatString the item label format string (<code>null</code> * not permitted). * @param xFormat the format object for the x values (<code>null</code> * not permitted). * @param yFormat the format object for the y values (<code>null</code> * not permitted). */ protected AbstractXYItemLabelGenerator(String formatString, NumberFormat xFormat, NumberFormat yFormat) { ParamChecks.nullNotPermitted(formatString, "formatString"); ParamChecks.nullNotPermitted(xFormat, "xFormat"); ParamChecks.nullNotPermitted(yFormat, "yFormat"); this.formatString = formatString; this.xFormat = xFormat; this.yFormat = yFormat; } /** * Creates an item label generator using the specified number formatters. * * @param formatString the item label format string (<code>null</code> * not permitted). * @param xFormat the format object for the x values (<code>null</code> * permitted). * @param yFormat the format object for the y values (<code>null</code> * not permitted). */ protected AbstractXYItemLabelGenerator(String formatString, DateFormat xFormat, NumberFormat yFormat) { this(formatString, NumberFormat.getInstance(), yFormat); this.xDateFormat = xFormat; } /** * Creates an item label generator using the specified formatters (a * number formatter for the x-values and a date formatter for the * y-values). * * @param formatString the item label format string (<code>null</code> * not permitted). * @param xFormat the format object for the x values (<code>null</code> * permitted). * @param yFormat the format object for the y values (<code>null</code> * not permitted). * * @since 1.0.4 */ protected AbstractXYItemLabelGenerator(String formatString, NumberFormat xFormat, DateFormat yFormat) { this(formatString, xFormat, NumberFormat.getInstance()); this.yDateFormat = yFormat; } /** * Creates an item label generator using the specified number formatters. * * @param formatString the item label format string (<code>null</code> * not permitted). * @param xFormat the format object for the x values (<code>null</code> * permitted). * @param yFormat the format object for the y values (<code>null</code> * not permitted). */ protected AbstractXYItemLabelGenerator(String formatString, DateFormat xFormat, DateFormat yFormat) { this(formatString, NumberFormat.getInstance(), NumberFormat.getInstance()); this.xDateFormat = xFormat; this.yDateFormat = yFormat; } /** * Returns the format string (this controls the overall structure of the * label). * * @return The format string (never <code>null</code>). */ public String getFormatString() { return this.formatString; } /** * Returns the number formatter for the x-values. * * @return The number formatter (possibly <code>null</code>). */ public NumberFormat getXFormat() { return this.xFormat; } /** * Returns the date formatter for the x-values. * * @return The date formatter (possibly <code>null</code>). */ public DateFormat getXDateFormat() { return this.xDateFormat; } /** * Returns the number formatter for the y-values. * * @return The number formatter (possibly <code>null</code>). */ public NumberFormat getYFormat() { return this.yFormat; } /** * Returns the date formatter for the y-values. * * @return The date formatter (possibly <code>null</code>). */ public DateFormat getYDateFormat() { return this.yDateFormat; } /** * Generates a label string for an item in the dataset. * * @param dataset the dataset (<code>null</code> not permitted). * @param series the series (zero-based index). * @param item the item (zero-based index). * * @return The label (possibly <code>null</code>). */ public String generateLabelString(XYDataset dataset, int series, int item) { String result; Object[] items = createItemArray(dataset, series, item); result = MessageFormat.format(this.formatString, items); return result; } /** * Returns the string representing a null value. * * @return The string representing a null value. * * @since 1.0.10 */ public String getNullYString() { return this.nullYString; } /** * Creates the array of items that can be passed to the * {@link MessageFormat} class for creating labels. * * @param dataset the dataset (<code>null</code> not permitted). * @param series the series (zero-based index). * @param item the item (zero-based index). * * @return An array of three items from the dataset formatted as * <code>String</code> objects (never <code>null</code>). */ protected Object[] createItemArray(XYDataset dataset, int series, int item) { Object[] result = new Object[3]; result[0] = dataset.getSeriesKey(series).toString(); double x = dataset.getXValue(series, item); if (this.xDateFormat != null) { result[1] = this.xDateFormat.format(new Date((long) x)); } else { result[1] = this.xFormat.format(x); } double y = dataset.getYValue(series, item); if (Double.isNaN(y) && dataset.getY(series, item) == null) { result[2] = this.nullYString; } else { if (this.yDateFormat != null) { result[2] = this.yDateFormat.format(new Date((long) y)); } else { result[2] = this.yFormat.format(y); } } return result; } /** * Tests this object for equality with an arbitrary object. * * @param obj the other object (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof AbstractXYItemLabelGenerator)) { return false; } AbstractXYItemLabelGenerator that = (AbstractXYItemLabelGenerator) obj; if (!this.formatString.equals(that.formatString)) { return false; } if (!ObjectUtilities.equal(this.xFormat, that.xFormat)) { return false; } if (!ObjectUtilities.equal(this.xDateFormat, that.xDateFormat)) { return false; } if (!ObjectUtilities.equal(this.yFormat, that.yFormat)) { return false; } if (!ObjectUtilities.equal(this.yDateFormat, that.yDateFormat)) { return false; } if (!this.nullYString.equals(that.nullYString)) { return false; } return true; } /** * Returns a hash code for this instance. * * @return A hash code. */ @Override public int hashCode() { int result = 127; result = HashUtilities.hashCode(result, this.formatString); result = HashUtilities.hashCode(result, this.xFormat); result = HashUtilities.hashCode(result, this.xDateFormat); result = HashUtilities.hashCode(result, this.yFormat); result = HashUtilities.hashCode(result, this.yDateFormat); return result; } /** * Returns an independent copy of the generator. * * @return A clone. * * @throws CloneNotSupportedException if cloning is not supported. */ @Override public Object clone() throws CloneNotSupportedException { AbstractXYItemLabelGenerator clone = (AbstractXYItemLabelGenerator) super.clone(); if (this.xFormat != null) { clone.xFormat = (NumberFormat) this.xFormat.clone(); } if (this.yFormat != null) { clone.yFormat = (NumberFormat) this.yFormat.clone(); } if (this.xDateFormat != null) { clone.xDateFormat = (DateFormat) this.xDateFormat.clone(); } if (this.yDateFormat != null) { clone.yDateFormat = (DateFormat) this.yDateFormat.clone(); } return clone; } }