standardpieitemlabelgenerator.java

jfreechart安装程序和使用说明

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ----------------------------------
 * StandardPieItemLabelGenerator.java
 * ----------------------------------
 * (C) Copyright 2001-2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Richard Atkinson;
 *                   Andreas Schroeder;
 *
 * $Id: StandardPieItemLabelGenerator.java,v 1.1 2004/08/31 14:36:24 mungady Exp $
 *
 * Changes
 * -------
 * 13-Dec-2001 : Version 1 (DG);
 * 16-Jan-2002 : Completed Javadocs (DG);
 * 29-Aug-2002 : Changed to format numbers using default locale (RA);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 30-Oct-2002 : Changed PieToolTipGenerator interface (DG);
 * 21-Mar-2003 : Implemented Serializable (DG);
 * 13-Aug-2003 : Implemented Cloneable (DG);
 * 19-Aug-2003 : Renamed StandardPieToolTipGenerator --> StandardPieItemLabelGenerator (DG);
 * 10-Mar-2004 : Modified to use MessageFormat class (DG);
 * 31-Mar-2004 : Added javadocs for the MessageFormat usage (AS);
 * 15-Apr-2004 : Split PieItemLabelGenerator interface into PieSectionLabelGenerator and
 *               PieToolTipGenerator (DG);
 */

package org.jfree.chart.labels;

import java.io.Serializable;
import java.text.MessageFormat;
import java.text.NumberFormat;

import org.jfree.data.general.DatasetUtilities;
import org.jfree.data.general.PieDataset;

/**
 * A standard item label generator for plots that use data from a {@link PieDataset}.
 * <p>
 * For the label format, use {0} where the pie section key should be inserted,
 * {1} for the absolute section value and {2} for the percent amount of the pie
 * section, e.g. <code>"{0} = {1} ({2})"</code> will display as  
 * <code>apple = 120 (5%)</code>.
 */
public class StandardPieItemLabelGenerator implements PieToolTipGenerator,
                                                      PieSectionLabelGenerator, 
                                                      Cloneable,
                                                      Serializable {

    /** The default tooltip format. */
    public static final String DEFAULT_TOOLTIP_FORMAT = "{0}: ({1}, {2})";

    /** The default section label format. */
    public static final String DEFAULT_SECTION_LABEL_FORMAT = "{0} = {1}";

    /** 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 default number formatters.
     */
    public StandardPieItemLabelGenerator() {
        this(
            DEFAULT_SECTION_LABEL_FORMAT, 
            NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance()
        );
    }

    /**
     * Creates an item label generator.
     * 
     * @param labelFormat  the label format.
     */
    public StandardPieItemLabelGenerator(String labelFormat) {
        this(labelFormat, NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance());   
    }
    
    /**
     * 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).
     */
    public StandardPieItemLabelGenerator(String labelFormat,
                                         NumberFormat numberFormat, 
                                         NumberFormat percentFormat) {

        if (labelFormat == null) {
            throw new IllegalArgumentException("Null 'itemLabelFormat' argument.");   
        }
        if (numberFormat == null) {
            throw new IllegalArgumentException("Null 'numberFormat' argument.");   
        }
        if (percentFormat == null) {
            throw new IllegalArgumentException("Null 'percentFormat' argument.");   
        }
        this.labelFormat = labelFormat;
        this.numberFormat = numberFormat;
        this.percentFormat = percentFormat;

    }

    /**
     * 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;
    }

    /**
     * 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>).
     */
    public 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;
    }

    /**
     * Generates a tool tip text item for one section in a pie chart.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param key  the section key (<code>null</code> not permitted).
     *
     * @return The tool tip text (possibly <code>null</code>).
     */
    public String generateToolTip(PieDataset dataset, Comparable key) {
        return generateSectionLabel(dataset, key);
    }

    /**
     * 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 key  the key.
     *
     * @return The items (never <code>null</code>).
     */
    protected Object[] createItemArray(PieDataset dataset, Comparable key) {
        Object[] result = new Object[3];
        result[0] = key.toString();
        Number value = dataset.getValue(key);
        result[1] = this.numberFormat.format(value);  
        double percent = 0.0;
        if (value != null) {
            double v = value.doubleValue();
            if (v > 0.0) {
                percent = v / DatasetUtilities.calculatePieDatasetTotal(dataset); 
            }
        }       
        result[2] = this.percentFormat.format(percent);
        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.
     */
    public boolean equals(Object obj) {

        if (obj == null) {
            return false;
        }
        if (obj == this) {
            return true;
        }

        if (obj instanceof StandardPieItemLabelGenerator) {
            StandardPieItemLabelGenerator generator = (StandardPieItemLabelGenerator) obj;
            if (!this.labelFormat.equals(generator.labelFormat)) {
                return false;
            }
            if (!this.numberFormat.equals(generator.numberFormat)) {
                return false;   
            }
            if (!this.percentFormat.equals(generator.percentFormat)) {
                return false;   
            }
            return true;
        }
        return false;

    }

    /**
     * Returns an independent copy of the generator.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException  should not happen.
     */
    public Object clone() throws CloneNotSupportedException {
        
        StandardPieItemLabelGenerator clone = (StandardPieItemLabelGenerator) super.clone();
        if (this.numberFormat != null) {
            clone.numberFormat = (NumberFormat) this.numberFormat.clone();
        } 
        return clone;
        
    }

}