    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    025 * Other names may be trademarks of their respective owners.]
    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
    041package org.jfree.chart.plot;
    042
    043import java.io.Serializable;
    044import 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 */
    052public 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}