001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: AbstractPieLabelDistributor.java,v 1.1.2.1 2007/06/14 15:04:21 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 14-Jun-2007 : Version 1 (DG);
040 *
041 */
042
043 package org.jfree.chart.plot;
044
045 import java.io.Serializable;
046 import java.util.List;
047
048 /**
049 * A base class for handling the distribution of pie section labels. Create
050 * your own subclass and set it using the
051 * {@link PiePlot#setLabelDistributor(AbstractPieLabelDistributor)} method
052 * if you want to customise the label distribution.
053 */
054 public abstract class AbstractPieLabelDistributor implements Serializable {
055
056 /** The label records. */
057 protected List labels;
058
059 /**
060 * Creates a new instance.
061 */
062 public AbstractPieLabelDistributor() {
063 this.labels = new java.util.ArrayList();
064 }
065
066 /**
067 * Returns a label record from the list.
068 *
069 * @param index the index.
070 *
071 * @return The label record.
072 */
073 public PieLabelRecord getPieLabelRecord(int index) {
074 return (PieLabelRecord) this.labels.get(index);
075 }
076
077 /**
078 * Adds a label record.
079 *
080 * @param record the label record (<code>null</code> not permitted).
081 */
082 public void addPieLabelRecord(PieLabelRecord record) {
083 if (record == null) {
084 throw new IllegalArgumentException("Null 'record' argument.");
085 }
086 this.labels.add(record);
087 }
088
089 /**
090 * Returns the number of items in the list.
091 *
092 * @return The item count.
093 */
094 public int getItemCount() {
095 return this.labels.size();
096 }
097
098 /**
099 * Clears the list of labels.
100 */
101 public void clear() {
102 this.labels.clear();
103 }
104
105 /**
106 * Called by the {@link PiePlot} class. Implementations should distribute
107 * the labels in this.labels then return.
108 *
109 * @param minY the y-coordinate for the top of the label area.
110 * @param height the height of the label area.
111 */
112 public abstract void distributeLabels(double minY, double height);
113
114 }