001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 2001-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 13-Dec-2001 : Version 1 (DG);
038 * 16-Jan-2002 : Completed Javadocs (DG);
039 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
040 * 30-Oct-2002 : Category is now a Comparable instance (DG);
041 * 07-Mar-2003 : Changed to KeyedValuesDataset and added pieIndex
042 * parameter (DG);
043 * 21-Mar-2003 : Updated Javadocs (DG);
044 * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
045 * 13-Aug-2003 : Added clone() method (DG);
046 * 19-Aug-2003 : Renamed PieToolTipGenerator --> PieItemLabelGenerator (DG);
047 * 11-Nov-2003 : Removed clone() method (DG);
048 * 30-Jan-2004 : Added generateSectionLabel() method (DG);
049 * 15-Apr-2004 : Moved generateToolTip() method into separate interface and
050 * renamed this interface PieSectionLabelGenerator (DG);
051 *
052 */
053
054 package org.jfree.chart.labels;
055
056 import java.awt.Font;
057 import java.awt.Paint;
058 import java.awt.font.TextAttribute;
059 import java.text.AttributedString;
060
061 import org.jfree.data.general.PieDataset;
062
063 /**
064 * Interface for a label generator for plots that use data from
065 * a {@link PieDataset}.
066 */
067 public interface PieSectionLabelGenerator {
068
069 /**
070 * Generates a label for a pie section.
071 *
072 * @param dataset the dataset (<code>null</code> not permitted).
073 * @param key the section key (<code>null</code> not permitted).
074 *
075 * @return The label (possibly <code>null</code>).
076 */
077 public String generateSectionLabel(PieDataset dataset, Comparable key);
078
079 /**
080 * Generates an attributed label for the specified series, or
081 * <code>null</code> if no attributed label is available (in which case,
082 * the string returned by
083 * {@link #generateSectionLabel(PieDataset, Comparable)} will
084 * provide the fallback). Only certain attributes are recognised by the
085 * code that ultimately displays the labels:
086 * <ul>
087 * <li>{@link TextAttribute#FONT}: will set the font;</li>
088 * <li>{@link TextAttribute#POSTURE}: a value of
089 * {@link TextAttribute#POSTURE_OBLIQUE} will add {@link Font#ITALIC} to
090 * the current font;</li>
091 * <li>{@link TextAttribute#WEIGHT}: a value of
092 * {@link TextAttribute#WEIGHT_BOLD} will add {@link Font#BOLD} to the
093 * current font;</li>
094 * <li>{@link TextAttribute#FOREGROUND}: this will set the {@link Paint}
095 * for the current</li>
096 * <li>{@link TextAttribute#SUPERSCRIPT}: the values
097 * {@link TextAttribute#SUPERSCRIPT_SUB} and
098 * {@link TextAttribute#SUPERSCRIPT_SUPER} are recognised.</li>
099 * </ul>
100 *
101 * @param dataset the dataset.
102 * @param key the key.
103 *
104 * @return An attributed label (possibly <code>null</code>).
105 */
106 public AttributedString generateAttributedSectionLabel(PieDataset dataset,
107 Comparable key);
108
109 }