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 * AbstractXYItemLabelGenerator.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 * 27-Feb-2004 : Version 1 (DG);
038 * 12-May-2004 : Moved default tool tip format to
039 *               StandardXYToolTipGenerator (DG);
040 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with
041 *               getYValue() (DG);
042 * 08-Oct-2004 : Modified createItemArray() method to handle null values (DG);
043 * 10-Jan-2005 : Updated createItemArray() to use x, y primitives if
044 *               possible (DG);
045 * ------------- JFREECHART 1.0.x --------------------------------------------
046 * 26-Jan-2006 : Minor API doc update (DG);
047 * 25-Jan-2007 : Added new constructor and fixed bug in clone() method (DG);
048 * 16-Oct-2007 : Removed redundant code (DG);
049 * 23-Nov-2007 : Implemented hashCode() (DG);
050 * 26-May-2008 : Added accessor methods for nullYString and updated equals()
051 *               method (DG);
052 *
053 */
054
055package org.jfree.chart.labels;
056
057import java.io.Serializable;
058import java.text.DateFormat;
059import java.text.MessageFormat;
060import java.text.NumberFormat;
061import java.util.Date;
062
063import org.jfree.chart.HashUtilities;
064import org.jfree.data.xy.XYDataset;
065import org.jfree.util.ObjectUtilities;
066
067/**
068 * A base class for creating item label generators.
069 */
070public class AbstractXYItemLabelGenerator implements Cloneable, Serializable {
071
072    /** For serialization. */
073    private static final long serialVersionUID = 5869744396278660636L;
074
075    /** The item label format string. */
076    private String formatString;
077
078    /** A number formatter for the x value. */
079    private NumberFormat xFormat;
080
081    /** A date formatter for the x value. */
082    private DateFormat xDateFormat;
083
084    /** A formatter for the y value. */
085    private NumberFormat yFormat;
086
087    /** A date formatter for the y value. */
088    private DateFormat yDateFormat;
089
090    /** The string used to represent 'null' for the y-value. */
091    private String nullYString = "null";
092
093    /**
094     * Creates an item label generator using default number formatters.
095     */
096    protected AbstractXYItemLabelGenerator() {
097        this("{2}", NumberFormat.getNumberInstance(),
098                NumberFormat.getNumberInstance());
099    }
100
101    /**
102     * Creates an item label generator using the specified number formatters.
103     *
104     * @param formatString  the item label format string (<code>null</code>
105     *                      not permitted).
106     * @param xFormat  the format object for the x values (<code>null</code>
107     *                 not permitted).
108     * @param yFormat  the format object for the y values (<code>null</code>
109     *                 not permitted).
110     */
111    protected AbstractXYItemLabelGenerator(String formatString,
112                                           NumberFormat xFormat,
113                                           NumberFormat yFormat) {
114
115        if (formatString == null) {
116            throw new IllegalArgumentException("Null 'formatString' argument.");
117        }
118        if (xFormat == null) {
119            throw new IllegalArgumentException("Null 'xFormat' argument.");
120        }
121        if (yFormat == null) {
122            throw new IllegalArgumentException("Null 'yFormat' argument.");
123        }
124        this.formatString = formatString;
125        this.xFormat = xFormat;
126        this.yFormat = yFormat;
127
128    }
129
130    /**
131     * Creates an item label generator using the specified number formatters.
132     *
133     * @param formatString  the item label format string (<code>null</code>
134     *                      not permitted).
135     * @param xFormat  the format object for the x values (<code>null</code>
136     *                 permitted).
137     * @param yFormat  the format object for the y values (<code>null</code>
138     *                 not permitted).
139     */
140    protected AbstractXYItemLabelGenerator(String formatString,
141                                           DateFormat xFormat,
142                                           NumberFormat yFormat) {
143
144        this(formatString, NumberFormat.getInstance(), yFormat);
145        this.xDateFormat = xFormat;
146
147    }
148
149    /**
150     * Creates an item label generator using the specified formatters (a
151     * number formatter for the x-values and a date formatter for the
152     * y-values).
153     *
154     * @param formatString  the item label format string (<code>null</code>
155     *                      not permitted).
156     * @param xFormat  the format object for the x values (<code>null</code>
157     *                 permitted).
158     * @param yFormat  the format object for the y values (<code>null</code>
159     *                 not permitted).
160     *
161     * @since 1.0.4
162     */
163    protected AbstractXYItemLabelGenerator(String formatString,
164            NumberFormat xFormat, DateFormat yFormat) {
165
166        this(formatString, xFormat, NumberFormat.getInstance());
167        this.yDateFormat = yFormat;
168    }
169
170    /**
171     * Creates an item label generator using the specified number formatters.
172     *
173     * @param formatString  the item label format string (<code>null</code>
174     *                      not permitted).
175     * @param xFormat  the format object for the x values (<code>null</code>
176     *                 permitted).
177     * @param yFormat  the format object for the y values (<code>null</code>
178     *                 not permitted).
179     */
180    protected AbstractXYItemLabelGenerator(String formatString,
181                                           DateFormat xFormat,
182                                           DateFormat yFormat) {
183
184        this(formatString, NumberFormat.getInstance(),
185                NumberFormat.getInstance());
186        this.xDateFormat = xFormat;
187        this.yDateFormat = yFormat;
188
189    }
190
191    /**
192     * Returns the format string (this controls the overall structure of the
193     * label).
194     *
195     * @return The format string (never <code>null</code>).
196     */
197    public String getFormatString() {
198        return this.formatString;
199    }
200
201    /**
202     * Returns the number formatter for the x-values.
203     *
204     * @return The number formatter (possibly <code>null</code>).
205     */
206    public NumberFormat getXFormat() {
207        return this.xFormat;
208    }
209
210    /**
211     * Returns the date formatter for the x-values.
212     *
213     * @return The date formatter (possibly <code>null</code>).
214     */
215    public DateFormat getXDateFormat() {
216        return this.xDateFormat;
217    }
218
219    /**
220     * Returns the number formatter for the y-values.
221     *
222     * @return The number formatter (possibly <code>null</code>).
223     */
224    public NumberFormat getYFormat() {
225        return this.yFormat;
226    }
227
228    /**
229     * Returns the date formatter for the y-values.
230     *
231     * @return The date formatter (possibly <code>null</code>).
232     */
233    public DateFormat getYDateFormat() {
234        return this.yDateFormat;
235    }
236
237    /**
238     * Generates a label string for an item in the dataset.
239     *
240     * @param dataset  the dataset (<code>null</code> not permitted).
241     * @param series  the series (zero-based index).
242     * @param item  the item (zero-based index).
243     *
244     * @return The label (possibly <code>null</code>).
245     */
246    public String generateLabelString(XYDataset dataset, int series, int item) {
247        String result = null;
248        Object[] items = createItemArray(dataset, series, item);
249        result = MessageFormat.format(this.formatString, items);
250        return result;
251    }
252
253    /**
254     * Returns the string representing a null value.
255     *
256     * @return The string representing a null value.
257     *
258     * @since 1.0.10
259     */
260    public String getNullYString() {
261        return this.nullYString;
262    }
263
264    /**
265     * Creates the array of items that can be passed to the
266     * {@link MessageFormat} class for creating labels.
267     *
268     * @param dataset  the dataset (<code>null</code> not permitted).
269     * @param series  the series (zero-based index).
270     * @param item  the item (zero-based index).
271     *
272     * @return An array of three items from the dataset formatted as
273     *         <code>String</code> objects (never <code>null</code>).
274     */
275    protected Object[] createItemArray(XYDataset dataset, int series,
276                                       int item) {
277        Object[] result = new Object[3];
278        result[0] = dataset.getSeriesKey(series).toString();
279
280        double x = dataset.getXValue(series, item);
281        if (this.xDateFormat != null) {
282            result[1] = this.xDateFormat.format(new Date((long) x));
283        }
284        else {
285            result[1] = this.xFormat.format(x);
286        }
287
288        double y = dataset.getYValue(series, item);
289        if (Double.isNaN(y) && dataset.getY(series, item) == null) {
290            result[2] = this.nullYString;
291        }
292        else {
293            if (this.yDateFormat != null) {
294                result[2] = this.yDateFormat.format(new Date((long) y));
295            }
296            else {
297                result[2] = this.yFormat.format(y);
298            }
299        }
300        return result;
301    }
302
303    /**
304     * Tests this object for equality with an arbitrary object.
305     *
306     * @param obj  the other object (<code>null</code> permitted).
307     *
308     * @return A boolean.
309     */
310    public boolean equals(Object obj) {
311        if (obj == this) {
312            return true;
313        }
314        if (!(obj instanceof AbstractXYItemLabelGenerator)) {
315            return false;
316        }
317        AbstractXYItemLabelGenerator that = (AbstractXYItemLabelGenerator) obj;
318        if (!this.formatString.equals(that.formatString)) {
319            return false;
320        }
321        if (!ObjectUtilities.equal(this.xFormat, that.xFormat)) {
322            return false;
323        }
324        if (!ObjectUtilities.equal(this.xDateFormat, that.xDateFormat)) {
325            return false;
326        }
327        if (!ObjectUtilities.equal(this.yFormat, that.yFormat)) {
328            return false;
329        }
330        if (!ObjectUtilities.equal(this.yDateFormat, that.yDateFormat)) {
331            return false;
332        }
333        if (!this.nullYString.equals(that.nullYString)) {
334            return false;
335        }
336        return true;
337    }
338
339    /**
340     * Returns a hash code for this instance.
341     *
342     * @return A hash code.
343     */
344    public int hashCode() {
345        int result = 127;
346        result = HashUtilities.hashCode(result, this.formatString);
347        result = HashUtilities.hashCode(result, this.xFormat);
348        result = HashUtilities.hashCode(result, this.xDateFormat);
349        result = HashUtilities.hashCode(result, this.yFormat);
350        result = HashUtilities.hashCode(result, this.yDateFormat);
351        return result;
352    }
353
354    /**
355     * Returns an independent copy of the generator.
356     *
357     * @return A clone.
358     *
359     * @throws CloneNotSupportedException if cloning is not supported.
360     */
361    public Object clone() throws CloneNotSupportedException {
362        AbstractXYItemLabelGenerator clone
363                = (AbstractXYItemLabelGenerator) super.clone();
364        if (this.xFormat != null) {
365            clone.xFormat = (NumberFormat) this.xFormat.clone();
366        }
367        if (this.yFormat != null) {
368            clone.yFormat = (NumberFormat) this.yFormat.clone();
369        }
370        if (this.xDateFormat != null) {
371            clone.xDateFormat = (DateFormat) this.xDateFormat.clone();
372        }
373        if (this.yDateFormat != null) {
374            clone.yDateFormat = (DateFormat) this.yDateFormat.clone();
375        }
376        return clone;
377    }
378
379}