Source for org.jfree.chart.labels.PieSectionLabelGenerator

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * -----------------------------
  28:  * PieSectionLabelGenerator.java
  29:  * -----------------------------
  30:  * (C) Copyright 2001-2004, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: PieSectionLabelGenerator.java,v 1.3.2.2 2005/10/25 20:49:02 mungady Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 13-Dec-2001 : Version 1 (DG);
  40:  * 16-Jan-2002 : Completed Javadocs (DG);
  41:  * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
  42:  * 30-Oct-2002 : Category is now a Comparable instance (DG);
  43:  * 07-Mar-2003 : Changed to KeyedValuesDataset and added pieIndex 
  44:  *               parameter (DG);
  45:  * 21-Mar-2003 : Updated Javadocs (DG);
  46:  * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
  47:  * 13-Aug-2003 : Added clone() method (DG);
  48:  * 19-Aug-2003 : Renamed PieToolTipGenerator --> PieItemLabelGenerator (DG);
  49:  * 11-Nov-2003 : Removed clone() method (DG);
  50:  * 30-Jan-2004 : Added generateSectionLabel() method (DG);
  51:  * 15-Apr-2004 : Moved generateToolTip() method into separate interface and 
  52:  *               renamed this interface PieSectionLabelGenerator (DG);
  53:  *
  54:  */
  55: 
  56: package org.jfree.chart.labels;
  57: 
  58: import java.awt.Font;
  59: import java.awt.Paint;
  60: import java.awt.font.TextAttribute;
  61: import java.text.AttributedString;
  62: 
  63: import org.jfree.data.general.PieDataset;
  64: 
  65: /**
  66:  * Interface for a label generator for plots that use data from 
  67:  * a {@link PieDataset}.
  68:  */
  69: public interface PieSectionLabelGenerator {
  70: 
  71:     /**
  72:      * Generates a label for a pie section.
  73:      * 
  74:      * @param dataset  the dataset (<code>null</code> not permitted).
  75:      * @param key  the section key (<code>null</code> not permitted).
  76:      * 
  77:      * @return The label (possibly <code>null</code>).
  78:      */
  79:     public String generateSectionLabel(PieDataset dataset, Comparable key);
  80:         
  81:     /**
  82:      * Generates an attributed label for the specified series, or 
  83:      * <code>null</code> if no attributed label is available (in which case,
  84:      * the string returned by 
  85:      * {@link #generateSectionLabel(PieDataset, Comparable)} will 
  86:      * provide the fallback).  Only certain attributes are recognised by the 
  87:      * code that ultimately displays the labels: 
  88:      * <ul>
  89:      * <li>{@link TextAttribute#FONT}: will set the font;</li>
  90:      * <li>{@link TextAttribute#POSTURE}: a value of 
  91:      *     {@link TextAttribute#POSTURE_OBLIQUE} will add {@link Font#ITALIC} to
  92:      *     the current font;</li>
  93:      * <li>{@link TextAttribute#WEIGHT}: a value of 
  94:      *     {@link TextAttribute#WEIGHT_BOLD} will add {@link Font#BOLD} to the 
  95:      *     current font;</li>
  96:      * <li>{@link TextAttribute#FOREGROUND}: this will set the {@link Paint} 
  97:      *     for the current</li>
  98:      * <li>{@link TextAttribute#SUPERSCRIPT}: the values 
  99:      *     {@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: }