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.] * * ---------------------------------- * AbstractPieItemLabelGenerator.java * ---------------------------------- * (C) Copyright 2004-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 09-Nov-2004 : Version 1, draws out code from StandardPieItemLabelGenerator * and StandardPieToolTipGenerator (DG); * ------------- JFREECHART 1.0.x --------------------------------------------- * 03-May-2006 : Fixed bug 1480978, a problem in the clone() method (DG); * 23-Nov-2007 : Implemented hashCode() (DG); * 03-Jul-2013 : Use ParamChecks (DG); * */ package org.jfree.chart.labels; import java.io.Serializable; import java.text.MessageFormat; import java.text.NumberFormat; import org.jfree.chart.HashUtilities; import org.jfree.chart.util.ParamChecks; import org.jfree.data.general.DatasetUtilities; import org.jfree.data.general.PieDataset; /** * A base class used for generating pie chart item labels. */ public class AbstractPieItemLabelGenerator implements Serializable { /** For serialization. */ private static final long serialVersionUID = 7347703325267846275L; /** The label format string. */ private String labelFormat; /** A number formatter for the value. */ private NumberFormat numberFormat; /** A number formatter for the percentage. */ private NumberFormat percentFormat; /** * Creates an item label generator using the specified number formatters. * * @param labelFormat the label format string (<code>null</code> not * permitted). * @param numberFormat the format object for the values (<code>null</code> * not permitted). * @param percentFormat the format object for the percentages * (<code>null</code> not permitted). */ protected AbstractPieItemLabelGenerator(String labelFormat, NumberFormat numberFormat, NumberFormat percentFormat) { ParamChecks.nullNotPermitted(labelFormat, "labelFormat"); ParamChecks.nullNotPermitted(numberFormat, "numberFormat"); ParamChecks.nullNotPermitted(percentFormat, "percentFormat"); this.labelFormat = labelFormat; this.numberFormat = numberFormat; this.percentFormat = percentFormat; } /** * Returns the label format string. * * @return The label format string (never <code>null</code>). */ public String getLabelFormat() { return this.labelFormat; } /** * Returns the number formatter. * * @return The formatter (never <code>null</code>). */ public NumberFormat getNumberFormat() { return this.numberFormat; } /** * Returns the percent formatter. * * @return The formatter (never <code>null</code>). */ public NumberFormat getPercentFormat() { return this.percentFormat; } /** * Creates the array of items that can be passed to the * {@link MessageFormat} class for creating labels. The returned array * contains four values: * <ul> * <li>result[0] = the section key converted to a <code>String</code>;</li> * <li>result[1] = the formatted data value;</li> * <li>result[2] = the formatted percentage (of the total);</li> * <li>result[3] = the formatted total value.</li> * </ul> * * @param dataset the dataset (<code>null</code> not permitted). * @param key the key (<code>null</code> not permitted). * * @return The items (never <code>null</code>). */ protected Object[] createItemArray(PieDataset dataset, Comparable key) { Object[] result = new Object[4]; double total = DatasetUtilities.calculatePieDatasetTotal(dataset); result[0] = key.toString(); Number value = dataset.getValue(key); if (value != null) { result[1] = this.numberFormat.format(value); } else { result[1] = "null"; } double percent = 0.0; if (value != null) { double v = value.doubleValue(); if (v > 0.0) { percent = v / total; } } result[2] = this.percentFormat.format(percent); result[3] = this.numberFormat.format(total); return result; } /** * Generates a label for a pie section. * * @param dataset the dataset (<code>null</code> not permitted). * @param key the section key (<code>null</code> not permitted). * * @return The label (possibly <code>null</code>). */ protected String generateSectionLabel(PieDataset dataset, Comparable key) { String result = null; if (dataset != null) { Object[] items = createItemArray(dataset, key); result = MessageFormat.format(this.labelFormat, items); } return result; } /** * Tests the generator for equality with an arbitrary object. * * @param obj the object to test against (<code>null</code> permitted). * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof AbstractPieItemLabelGenerator)) { return false; } AbstractPieItemLabelGenerator that = (AbstractPieItemLabelGenerator) obj; if (!this.labelFormat.equals(that.labelFormat)) { return false; } if (!this.numberFormat.equals(that.numberFormat)) { return false; } if (!this.percentFormat.equals(that.percentFormat)) { 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.labelFormat); result = HashUtilities.hashCode(result, this.numberFormat); result = HashUtilities.hashCode(result, this.percentFormat); return result; } /** * Returns an independent copy of the generator. * * @return A clone. * * @throws CloneNotSupportedException should not happen. */ @Override public Object clone() throws CloneNotSupportedException { AbstractPieItemLabelGenerator clone = (AbstractPieItemLabelGenerator) super.clone(); if (this.numberFormat != null) { clone.numberFormat = (NumberFormat) this.numberFormat.clone(); } if (this.percentFormat != null) { clone.percentFormat = (NumberFormat) this.percentFormat.clone(); } return clone; } }