001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -----------------------------
028 * PieSectionLabelGenerator.java
029 * -----------------------------
030 * (C) Copyright 2001-2004, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: PieSectionLabelGenerator.java,v 1.3.2.2 2005/10/25 20:49:02 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 13-Dec-2001 : Version 1 (DG);
040 * 16-Jan-2002 : Completed Javadocs (DG);
041 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
042 * 30-Oct-2002 : Category is now a Comparable instance (DG);
043 * 07-Mar-2003 : Changed to KeyedValuesDataset and added pieIndex
044 * parameter (DG);
045 * 21-Mar-2003 : Updated Javadocs (DG);
046 * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
047 * 13-Aug-2003 : Added clone() method (DG);
048 * 19-Aug-2003 : Renamed PieToolTipGenerator --> PieItemLabelGenerator (DG);
049 * 11-Nov-2003 : Removed clone() method (DG);
050 * 30-Jan-2004 : Added generateSectionLabel() method (DG);
051 * 15-Apr-2004 : Moved generateToolTip() method into separate interface and
052 * renamed this interface PieSectionLabelGenerator (DG);
053 *
054 */
055
056 package org.jfree.chart.labels;
057
058 import java.awt.Font;
059 import java.awt.Paint;
060 import java.awt.font.TextAttribute;
061 import java.text.AttributedString;
062
063 import org.jfree.data.general.PieDataset;
064
065 /**
066 * Interface for a label generator for plots that use data from
067 * a {@link PieDataset}.
068 */
069 public interface PieSectionLabelGenerator {
070
071 /**
072 * Generates a label for a pie section.
073 *
074 * @param dataset the dataset (<code>null</code> not permitted).
075 * @param key the section key (<code>null</code> not permitted).
076 *
077 * @return The label (possibly <code>null</code>).
078 */
079 public String generateSectionLabel(PieDataset dataset, Comparable key);
080
081 /**
082 * Generates an attributed label for the specified series, or
083 * <code>null</code> if no attributed label is available (in which case,
084 * the string returned by
085 * {@link #generateSectionLabel(PieDataset, Comparable)} will
086 * provide the fallback). Only certain attributes are recognised by the
087 * code that ultimately displays the labels:
088 * <ul>
089 * <li>{@link TextAttribute#FONT}: will set the font;</li>
090 * <li>{@link TextAttribute#POSTURE}: a value of
091 * {@link TextAttribute#POSTURE_OBLIQUE} will add {@link Font#ITALIC} to
092 * the current font;</li>
093 * <li>{@link TextAttribute#WEIGHT}: a value of
094 * {@link TextAttribute#WEIGHT_BOLD} will add {@link Font#BOLD} to the
095 * current font;</li>
096 * <li>{@link TextAttribute#FOREGROUND}: this will set the {@link Paint}
097 * for the current</li>
098 * <li>{@link TextAttribute#SUPERSCRIPT}: the values
099 * {@link TextAttribute#SUPERSCRIPT_SUB} and
100 * {@link TextAttribute#SUPERSCRIPT_SUPER} are recognised.</li>
101 * </ul>
102 *
103 * @param dataset the dataset.
104 * @param key the key.
105 *
106 * @return An attributed label (possibly <code>null</code>).
107 */
108 public AttributedString generateAttributedSectionLabel(PieDataset dataset,
109 Comparable key);
110
111 }