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 * AbstractPieItemLabelGenerator.java
029 * ----------------------------------
030 * (C) Copyright 2004-2008, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 09-Nov-2004 : Version 1, draws out code from StandardPieItemLabelGenerator
038 *               and StandardPieToolTipGenerator (DG);
039 * ------------- JFREECHART 1.0.x ---------------------------------------------
040 * 03-May-2006 : Fixed bug 1480978, a problem in the clone() method (DG);
041 * 23-Nov-2007 : Implemented hashCode() (DG);
042 *
043 */
044
045package org.jfree.chart.labels;
046
047import java.io.Serializable;
048import java.text.MessageFormat;
049import java.text.NumberFormat;
050
051import org.jfree.chart.HashUtilities;
052import org.jfree.data.general.DatasetUtilities;
053import org.jfree.data.general.PieDataset;
054
055/**
056 * A base class used for generating pie chart item labels.
057 */
058public class AbstractPieItemLabelGenerator implements Serializable {
059
060    /** For serialization. */
061    private static final long serialVersionUID = 7347703325267846275L;
062
063    /** The label format string. */
064    private String labelFormat;
065
066    /** A number formatter for the value. */
067    private NumberFormat numberFormat;
068
069    /** A number formatter for the percentage. */
070    private NumberFormat percentFormat;
071
072    /**
073     * Creates an item label generator using the specified number formatters.
074     *
075     * @param labelFormat  the label format string (<code>null</code> not
076     *                     permitted).
077     * @param numberFormat  the format object for the values (<code>null</code>
078     *                      not permitted).
079     * @param percentFormat  the format object for the percentages
080     *                       (<code>null</code> not permitted).
081     */
082    protected AbstractPieItemLabelGenerator(String labelFormat,
083                                            NumberFormat numberFormat,
084                                            NumberFormat percentFormat) {
085
086        if (labelFormat == null) {
087            throw new IllegalArgumentException("Null 'labelFormat' argument.");
088        }
089        if (numberFormat == null) {
090            throw new IllegalArgumentException("Null 'numberFormat' argument.");
091        }
092        if (percentFormat == null) {
093            throw new IllegalArgumentException(
094                    "Null 'percentFormat' argument.");
095        }
096        this.labelFormat = labelFormat;
097        this.numberFormat = numberFormat;
098        this.percentFormat = percentFormat;
099
100    }
101
102    /**
103     * Returns the label format string.
104     *
105     * @return The label format string (never <code>null</code>).
106     */
107    public String getLabelFormat() {
108        return this.labelFormat;
109    }
110
111    /**
112     * Returns the number formatter.
113     *
114     * @return The formatter (never <code>null</code>).
115     */
116    public NumberFormat getNumberFormat() {
117        return this.numberFormat;
118    }
119
120    /**
121     * Returns the percent formatter.
122     *
123     * @return The formatter (never <code>null</code>).
124     */
125    public NumberFormat getPercentFormat() {
126        return this.percentFormat;
127    }
128
129    /**
130     * Creates the array of items that can be passed to the
131     * {@link MessageFormat} class for creating labels.  The returned array
132     * contains four values:
133     * <ul>
134     * <li>result[0] = the section key converted to a <code>String</code>;</li>
135     * <li>result[1] = the formatted data value;</li>
136     * <li>result[2] = the formatted percentage (of the total);</li>
137     * <li>result[3] = the formatted total value.</li>
138     * </ul>
139     *
140     * @param dataset  the dataset (<code>null</code> not permitted).
141     * @param key  the key (<code>null</code> not permitted).
142     *
143     * @return The items (never <code>null</code>).
144     */
145    protected Object[] createItemArray(PieDataset dataset, Comparable key) {
146        Object[] result = new Object[4];
147        double total = DatasetUtilities.calculatePieDatasetTotal(dataset);
148        result[0] = key.toString();
149        Number value = dataset.getValue(key);
150        if (value != null) {
151            result[1] = this.numberFormat.format(value);
152        }
153        else {
154            result[1] = "null";
155        }
156        double percent = 0.0;
157        if (value != null) {
158            double v = value.doubleValue();
159            if (v > 0.0) {
160                percent = v / total;
161            }
162        }
163        result[2] = this.percentFormat.format(percent);
164        result[3] = this.numberFormat.format(total);
165        return result;
166    }
167
168    /**
169     * Generates a label for a pie section.
170     *
171     * @param dataset  the dataset (<code>null</code> not permitted).
172     * @param key  the section key (<code>null</code> not permitted).
173     *
174     * @return The label (possibly <code>null</code>).
175     */
176    protected String generateSectionLabel(PieDataset dataset, Comparable key) {
177        String result = null;
178        if (dataset != null) {
179            Object[] items = createItemArray(dataset, key);
180            result = MessageFormat.format(this.labelFormat, items);
181        }
182        return result;
183    }
184
185    /**
186     * Tests the generator for equality with an arbitrary object.
187     *
188     * @param obj  the object to test against (<code>null</code> permitted).
189     *
190     * @return A boolean.
191     */
192    public boolean equals(Object obj) {
193        if (obj == this) {
194            return true;
195        }
196        if (!(obj instanceof AbstractPieItemLabelGenerator)) {
197            return false;
198        }
199
200        AbstractPieItemLabelGenerator that
201                = (AbstractPieItemLabelGenerator) obj;
202        if (!this.labelFormat.equals(that.labelFormat)) {
203            return false;
204        }
205        if (!this.numberFormat.equals(that.numberFormat)) {
206            return false;
207        }
208        if (!this.percentFormat.equals(that.percentFormat)) {
209            return false;
210        }
211        return true;
212
213    }
214
215    /**
216     * Returns a hash code for this instance.
217     *
218     * @return A hash code.
219     */
220    public int hashCode() {
221        int result = 127;
222        result = HashUtilities.hashCode(result, this.labelFormat);
223        result = HashUtilities.hashCode(result, this.numberFormat);
224        result = HashUtilities.hashCode(result, this.percentFormat);
225        return result;
226    }
227
228    /**
229     * Returns an independent copy of the generator.
230     *
231     * @return A clone.
232     *
233     * @throws CloneNotSupportedException  should not happen.
234     */
235    public Object clone() throws CloneNotSupportedException {
236        AbstractPieItemLabelGenerator clone
237                = (AbstractPieItemLabelGenerator) super.clone();
238        if (this.numberFormat != null) {
239            clone.numberFormat = (NumberFormat) this.numberFormat.clone();
240        }
241        if (this.percentFormat != null) {
242            clone.percentFormat = (NumberFormat) this.percentFormat.clone();
243        }
244        return clone;
245    }
246
247}