jfreechart example source code file (PieSectionLabelGenerator.java)

This example jfreechart source code file (PieSectionLabelGenerator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

attributedstring, attributedstring, awt, comparable, comparable, font, piesectionlabelgenerator, piesectionlabelgenerator, string, string, text

The jfreechart PieSectionLabelGenerator.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * -----------------------------
 * PieSectionLabelGenerator.java
 * -----------------------------
 * (C) Copyright 2001-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 13-Dec-2001 : Version 1 (DG);
 * 16-Jan-2002 : Completed Javadocs (DG);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 30-Oct-2002 : Category is now a Comparable instance (DG);
 * 07-Mar-2003 : Changed to KeyedValuesDataset and added pieIndex
 *               parameter (DG);
 * 21-Mar-2003 : Updated Javadocs (DG);
 * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
 * 13-Aug-2003 : Added clone() method (DG);
 * 19-Aug-2003 : Renamed PieToolTipGenerator --> PieItemLabelGenerator (DG);
 * 11-Nov-2003 : Removed clone() method (DG);
 * 30-Jan-2004 : Added generateSectionLabel() method (DG);
 * 15-Apr-2004 : Moved generateToolTip() method into separate interface and
 *               renamed this interface PieSectionLabelGenerator (DG);
 *
 */

package org.jfree.chart.labels;

import java.awt.Font;
import java.awt.Paint;
import java.awt.font.TextAttribute;
import java.text.AttributedString;

import org.jfree.data.general.PieDataset;

/**
 * Interface for a label generator for plots that use data from
 * a {@link PieDataset}.
 */
public interface PieSectionLabelGenerator {

    /**
     * Generates a label for a pie section.
     *
     * @param dataset  the dataset (<code>null not permitted).
     * @param key  the section key (<code>null not permitted).
     *
     * @return The label (possibly <code>null).
     */
    public String generateSectionLabel(PieDataset dataset, Comparable key);

    /**
     * Generates an attributed label for the specified series, or
     * <code>null if no attributed label is available (in which case,
     * the string returned by
     * {@link #generateSectionLabel(PieDataset, Comparable)} will
     * provide the fallback).  Only certain attributes are recognised by the
     * code that ultimately displays the labels:
     * <ul>
     * <li>{@link TextAttribute#FONT}: will set the font;
     * <li>{@link TextAttribute#POSTURE}: a value of
     *     {@link TextAttribute#POSTURE_OBLIQUE} will add {@link Font#ITALIC} to
     *     the current font;</li>
     * <li>{@link TextAttribute#WEIGHT}: a value of
     *     {@link TextAttribute#WEIGHT_BOLD} will add {@link Font#BOLD} to the
     *     current font;</li>
     * <li>{@link TextAttribute#FOREGROUND}: this will set the {@link Paint}
     *     for the current</li>
     * <li>{@link TextAttribute#SUPERSCRIPT}: the values
     *     {@link TextAttribute#SUPERSCRIPT_SUB} and
     *     {@link TextAttribute#SUPERSCRIPT_SUPER} are recognised.</li>
     * </ul>
     *
     * @param dataset  the dataset.
     * @param key  the key.
     *
     * @return An attributed label (possibly <code>null).
     */
    public AttributedString generateAttributedSectionLabel(PieDataset dataset,
                                                           Comparable key);

}