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 * AbstractPieLabelDistributor.java
029 * --------------------------------
030 * (C) Copyright 2007, 2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 14-Jun-2007 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.chart.plot;
042
043 import java.io.Serializable;
044 import java.util.List;
045
046 /**
047 * A base class for handling the distribution of pie section labels. Create
048 * your own subclass and set it using the
049 * {@link PiePlot#setLabelDistributor(AbstractPieLabelDistributor)} method
050 * if you want to customise the label distribution.
051 */
052 public abstract class AbstractPieLabelDistributor implements Serializable {
053
054 /** The label records. */
055 protected List labels;
056
057 /**
058 * Creates a new instance.
059 */
060 public AbstractPieLabelDistributor() {
061 this.labels = new java.util.ArrayList();
062 }
063
064 /**
065 * Returns a label record from the list.
066 *
067 * @param index the index.
068 *
069 * @return The label record.
070 */
071 public PieLabelRecord getPieLabelRecord(int index) {
072 return (PieLabelRecord) this.labels.get(index);
073 }
074
075 /**
076 * Adds a label record.
077 *
078 * @param record the label record (<code>null</code> not permitted).
079 */
080 public void addPieLabelRecord(PieLabelRecord record) {
081 if (record == null) {
082 throw new IllegalArgumentException("Null 'record' argument.");
083 }
084 this.labels.add(record);
085 }
086
087 /**
088 * Returns the number of items in the list.
089 *
090 * @return The item count.
091 */
092 public int getItemCount() {
093 return this.labels.size();
094 }
095
096 /**
097 * Clears the list of labels.
098 */
099 public void clear() {
100 this.labels.clear();
101 }
102
103 /**
104 * Called by the {@link PiePlot} class. Implementations should distribute
105 * the labels in this.labels then return.
106 *
107 * @param minY the y-coordinate for the top of the label area.
108 * @param height the height of the label area.
109 */
110 public abstract void distributeLabels(double minY, double height);
111
112 }