1 /*
2 * Copyright 1996-2005 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 /*
27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
29 *
30 * The original version of this source code and documentation is copyrighted
31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
32 * materials are provided under terms of a License Agreement between Taligent
33 * and Sun. This technology is protected by multiple US and International
34 * patents. This notice and attribution to Taligent may not be removed.
35 * Taligent is a registered trademark of Taligent, Inc.
36 *
37 */
38
39 package java.text;
40
41 import java.io.InvalidObjectException;
42 import java.io.IOException;
43 import java.io.ObjectInputStream;
44 import java.util.Arrays;
45
46 /**
47 * A <code>ChoiceFormat</code> allows you to attach a format to a range of numbers.
48 * It is generally used in a <code>MessageFormat</code> for handling plurals.
49 * The choice is specified with an ascending list of doubles, where each item
50 * specifies a half-open interval up to the next item:
51 * <blockquote>
52 * <pre>
53 * X matches j if and only if limit[j] <= X < limit[j+1]
54 * </pre>
55 * </blockquote>
56 * If there is no match, then either the first or last index is used, depending
57 * on whether the number (X) is too low or too high. If the limit array is not
58 * in ascending order, the results of formatting will be incorrect. ChoiceFormat
59 * also accepts <code>\u221E</code> as equivalent to infinity(INF).
60 *
61 * <p>
62 * <strong>Note:</strong>
63 * <code>ChoiceFormat</code> differs from the other <code>Format</code>
64 * classes in that you create a <code>ChoiceFormat</code> object with a
65 * constructor (not with a <code>getInstance</code> style factory
66 * method). The factory methods aren't necessary because <code>ChoiceFormat</code>
67 * doesn't require any complex setup for a given locale. In fact,
68 * <code>ChoiceFormat</code> doesn't implement any locale specific behavior.
69 *
70 * <p>
71 * When creating a <code>ChoiceFormat</code>, you must specify an array of formats
72 * and an array of limits. The length of these arrays must be the same.
73 * For example,
74 * <ul>
75 * <li>
76 * <em>limits</em> = {1,2,3,4,5,6,7}<br>
77 * <em>formats</em> = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}
78 * <li>
79 * <em>limits</em> = {0, 1, ChoiceFormat.nextDouble(1)}<br>
80 * <em>formats</em> = {"no files", "one file", "many files"}<br>
81 * (<code>nextDouble</code> can be used to get the next higher double, to
82 * make the half-open interval.)
83 * </ul>
84 *
85 * <p>
86 * Here is a simple example that shows formatting and parsing:
87 * <blockquote>
88 * <pre>
89 * double[] limits = {1,2,3,4,5,6,7};
90 * String[] dayOfWeekNames = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"};
91 * ChoiceFormat form = new ChoiceFormat(limits, dayOfWeekNames);
92 * ParsePosition status = new ParsePosition(0);
93 * for (double i = 0.0; i <= 8.0; ++i) {
94 * status.setIndex(0);
95 * System.out.println(i + " -> " + form.format(i) + " -> "
96 * + form.parse(form.format(i),status));
97 * }
98 * </pre>
99 * </blockquote>
100 * Here is a more complex example, with a pattern format:
101 * <blockquote>
102 * <pre>
103 * double[] filelimits = {0,1,2};
104 * String[] filepart = {"are no files","is one file","are {2} files"};
105 * ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart);
106 * Format[] testFormats = {fileform, null, NumberFormat.getInstance()};
107 * MessageFormat pattform = new MessageFormat("There {0} on {1}");
108 * pattform.setFormats(testFormats);
109 * Object[] testArgs = {null, "ADisk", null};
110 * for (int i = 0; i < 4; ++i) {
111 * testArgs[0] = new Integer(i);
112 * testArgs[2] = testArgs[0];
113 * System.out.println(pattform.format(testArgs));
114 * }
115 * </pre>
116 * </blockquote>
117 * <p>
118 * Specifying a pattern for ChoiceFormat objects is fairly straightforward.
119 * For example:
120 * <blockquote>
121 * <pre>
122 * ChoiceFormat fmt = new ChoiceFormat(
123 * "-1#is negative| 0#is zero or fraction | 1#is one |1.0<is 1+ |2#is two |2<is more than 2.");
124 * System.out.println("Formatter Pattern : " + fmt.toPattern());
125 *
126 * System.out.println("Format with -INF : " + fmt.format(Double.NEGATIVE_INFINITY));
127 * System.out.println("Format with -1.0 : " + fmt.format(-1.0));
128 * System.out.println("Format with 0 : " + fmt.format(0));
129 * System.out.println("Format with 0.9 : " + fmt.format(0.9));
130 * System.out.println("Format with 1.0 : " + fmt.format(1));
131 * System.out.println("Format with 1.5 : " + fmt.format(1.5));
132 * System.out.println("Format with 2 : " + fmt.format(2));
133 * System.out.println("Format with 2.1 : " + fmt.format(2.1));
134 * System.out.println("Format with NaN : " + fmt.format(Double.NaN));
135 * System.out.println("Format with +INF : " + fmt.format(Double.POSITIVE_INFINITY));
136 * </pre>
137 * </blockquote>
138 * And the output result would be like the following:
139 * <pre>
140 * <blockquote>
141 * Format with -INF : is negative
142 * Format with -1.0 : is negative
143 * Format with 0 : is zero or fraction
144 * Format with 0.9 : is zero or fraction
145 * Format with 1.0 : is one
146 * Format with 1.5 : is 1+
147 * Format with 2 : is two
148 * Format with 2.1 : is more than 2.
149 * Format with NaN : is negative
150 * Format with +INF : is more than 2.
151 * </pre>
152 * </blockquote>
153 *
154 * <h4><a name="synchronization">Synchronization</a></h4>
155 *
156 * <p>
157 * Choice formats are not synchronized.
158 * It is recommended to create separate format instances for each thread.
159 * If multiple threads access a format concurrently, it must be synchronized
160 * externally.
161 *
162 *
163 * @see DecimalFormat
164 * @see MessageFormat
165 * @author Mark Davis
166 */
167 public class ChoiceFormat extends NumberFormat {
168
169 // Proclaim serial compatibility with 1.1 FCS
170 private static final long serialVersionUID = 1795184449645032964L;
171
172 /**
173 * Sets the pattern.
174 * @param newPattern See the class description.
175 */
176 public void applyPattern(String newPattern) {
177 StringBuffer[] segments = new StringBuffer[2];
178 for (int i = 0; i < segments.length; ++i) {
179 segments[i] = new StringBuffer();
180 }
181 double[] newChoiceLimits = new double[30];
182 String[] newChoiceFormats = new String[30];
183 int count = 0;
184 int part = 0;
185 double startValue = 0;
186 double oldStartValue = Double.NaN;
187 boolean inQuote = false;
188 for (int i = 0; i < newPattern.length(); ++i) {
189 char ch = newPattern.charAt(i);
190 if (ch=='\'') {
191 // Check for "''" indicating a literal quote
192 if ((i+1)<newPattern.length() && newPattern.charAt(i+1)==ch) {
193 segments[part].append(ch);
194 ++i;
195 } else {
196 inQuote = !inQuote;
197 }
198 } else if (inQuote) {
199 segments[part].append(ch);
200 } else if (ch == '<' || ch == '#' || ch == '\u2264') {
201 if (segments[0].length() == 0) {
202 throw new IllegalArgumentException();
203 }
204 try {
205 String tempBuffer = segments[0].toString();
206 if (tempBuffer.equals("\u221E")) {
207 startValue = Double.POSITIVE_INFINITY;
208 } else if (tempBuffer.equals("-\u221E")) {
209 startValue = Double.NEGATIVE_INFINITY;
210 } else {
211 startValue = Double.valueOf(segments[0].toString()).doubleValue();
212 }
213 } catch (Exception e) {
214 throw new IllegalArgumentException();
215 }
216 if (ch == '<' && startValue != Double.POSITIVE_INFINITY &&
217 startValue != Double.NEGATIVE_INFINITY) {
218 startValue = nextDouble(startValue);
219 }
220 if (startValue <= oldStartValue) {
221 throw new IllegalArgumentException();
222 }
223 segments[0].setLength(0);
224 part = 1;
225 } else if (ch == '|') {
226 if (count == newChoiceLimits.length) {
227 newChoiceLimits = doubleArraySize(newChoiceLimits);
228 newChoiceFormats = doubleArraySize(newChoiceFormats);
229 }
230 newChoiceLimits[count] = startValue;
231 newChoiceFormats[count] = segments[1].toString();
232 ++count;
233 oldStartValue = startValue;
234 segments[1].setLength(0);
235 part = 0;
236 } else {
237 segments[part].append(ch);
238 }
239 }
240 // clean up last one
241 if (part == 1) {
242 if (count == newChoiceLimits.length) {
243 newChoiceLimits = doubleArraySize(newChoiceLimits);
244 newChoiceFormats = doubleArraySize(newChoiceFormats);
245 }
246 newChoiceLimits[count] = startValue;
247 newChoiceFormats[count] = segments[1].toString();
248 ++count;
249 }
250 choiceLimits = new double[count];
251 System.arraycopy(newChoiceLimits, 0, choiceLimits, 0, count);
252 choiceFormats = new String[count];
253 System.arraycopy(newChoiceFormats, 0, choiceFormats, 0, count);
254 }
255
256 /**
257 * Gets the pattern.
258 */
259 public String toPattern() {
260 StringBuffer result = new StringBuffer();
261 for (int i = 0; i < choiceLimits.length; ++i) {
262 if (i != 0) {
263 result.append('|');
264 }
265 // choose based upon which has less precision
266 // approximate that by choosing the closest one to an integer.
267 // could do better, but it's not worth it.
268 double less = previousDouble(choiceLimits[i]);
269 double tryLessOrEqual = Math.abs(Math.IEEEremainder(choiceLimits[i], 1.0d));
270 double tryLess = Math.abs(Math.IEEEremainder(less, 1.0d));
271
272 if (tryLessOrEqual < tryLess) {
273 result.append(""+choiceLimits[i]);
274 result.append('#');
275 } else {
276 if (choiceLimits[i] == Double.POSITIVE_INFINITY) {
277 result.append("\u221E");
278 } else if (choiceLimits[i] == Double.NEGATIVE_INFINITY) {
279 result.append("-\u221E");
280 } else {
281 result.append(""+less);
282 }
283 result.append('<');
284 }
285 // Append choiceFormats[i], using quotes if there are special characters.
286 // Single quotes themselves must be escaped in either case.
287 String text = choiceFormats[i];
288 boolean needQuote = text.indexOf('<') >= 0
289 || text.indexOf('#') >= 0
290 || text.indexOf('\u2264') >= 0
291 || text.indexOf('|') >= 0;
292 if (needQuote) result.append('\'');
293 if (text.indexOf('\'') < 0) result.append(text);
294 else {
295 for (int j=0; j<text.length(); ++j) {
296 char c = text.charAt(j);
297 result.append(c);
298 if (c == '\'') result.append(c);
299 }
300 }
301 if (needQuote) result.append('\'');
302 }
303 return result.toString();
304 }
305
306 /**
307 * Constructs with limits and corresponding formats based on the pattern.
308 * @see #applyPattern
309 */
310 public ChoiceFormat(String newPattern) {
311 applyPattern(newPattern);
312 }
313
314 /**
315 * Constructs with the limits and the corresponding formats.
316 * @see #setChoices
317 */
318 public ChoiceFormat(double[] limits, String[] formats) {
319 setChoices(limits, formats);
320 }
321
322 /**
323 * Set the choices to be used in formatting.
324 * @param limits contains the top value that you want
325 * parsed with that format,and should be in ascending sorted order. When
326 * formatting X, the choice will be the i, where
327 * limit[i] <= X < limit[i+1].
328 * If the limit array is not in ascending order, the results of formatting
329 * will be incorrect.
330 * @param formats are the formats you want to use for each limit.
331 * They can be either Format objects or Strings.
332 * When formatting with object Y,
333 * if the object is a NumberFormat, then ((NumberFormat) Y).format(X)
334 * is called. Otherwise Y.toString() is called.
335 */
336 public void setChoices(double[] limits, String formats[]) {
337 if (limits.length != formats.length) {
338 throw new IllegalArgumentException(
339 "Array and limit arrays must be of the same length.");
340 }
341 choiceLimits = limits;
342 choiceFormats = formats;
343 }
344
345 /**
346 * Get the limits passed in the constructor.
347 * @return the limits.
348 */
349 public double[] getLimits() {
350 return choiceLimits;
351 }
352
353 /**
354 * Get the formats passed in the constructor.
355 * @return the formats.
356 */
357 public Object[] getFormats() {
358 return choiceFormats;
359 }
360
361 // Overrides
362
363 /**
364 * Specialization of format. This method really calls
365 * <code>format(double, StringBuffer, FieldPosition)</code>
366 * thus the range of longs that are supported is only equal to
367 * the range that can be stored by double. This will never be
368 * a practical limitation.
369 */
370 public StringBuffer format(long number, StringBuffer toAppendTo,
371 FieldPosition status) {
372 return format((double)number, toAppendTo, status);
373 }
374
375 /**
376 * Returns pattern with formatted double.
377 * @param number number to be formatted & substituted.
378 * @param toAppendTo where text is appended.
379 * @param status ignore no useful status is returned.
380 */
381 public StringBuffer format(double number, StringBuffer toAppendTo,
382 FieldPosition status) {
383 // find the number
384 int i;
385 for (i = 0; i < choiceLimits.length; ++i) {
386 if (!(number >= choiceLimits[i])) {
387 // same as number < choiceLimits, except catchs NaN
388 break;
389 }
390 }
391 --i;
392 if (i < 0) i = 0;
393 // return either a formatted number, or a string
394 return toAppendTo.append(choiceFormats[i]);
395 }
396
397 /**
398 * Parses a Number from the input text.
399 * @param text the source text.
400 * @param status an input-output parameter. On input, the
401 * status.index field indicates the first character of the
402 * source text that should be parsed. On exit, if no error
403 * occured, status.index is set to the first unparsed character
404 * in the source text. On exit, if an error did occur,
405 * status.index is unchanged and status.errorIndex is set to the
406 * first index of the character that caused the parse to fail.
407 * @return A Number representing the value of the number parsed.
408 */
409 public Number parse(String text, ParsePosition status) {
410 // find the best number (defined as the one with the longest parse)
411 int start = status.index;
412 int furthest = start;
413 double bestNumber = Double.NaN;
414 double tempNumber = 0.0;
415 for (int i = 0; i < choiceFormats.length; ++i) {
416 String tempString = choiceFormats[i];
417 if (text.regionMatches(start, tempString, 0, tempString.length())) {
418 status.index = start + tempString.length();
419 tempNumber = choiceLimits[i];
420 if (status.index > furthest) {
421 furthest = status.index;
422 bestNumber = tempNumber;
423 if (furthest == text.length()) break;
424 }
425 }
426 }
427 status.index = furthest;
428 if (status.index == start) {
429 status.errorIndex = furthest;
430 }
431 return new Double(bestNumber);
432 }
433
434 /**
435 * Finds the least double greater than d.
436 * If NaN, returns same value.
437 * <p>Used to make half-open intervals.
438 * @see #previousDouble
439 */
440 public static final double nextDouble (double d) {
441 return nextDouble(d,true);
442 }
443
444 /**
445 * Finds the greatest double less than d.
446 * If NaN, returns same value.
447 * @see #nextDouble
448 */
449 public static final double previousDouble (double d) {
450 return nextDouble(d,false);
451 }
452
453 /**
454 * Overrides Cloneable
455 */
456 public Object clone()
457 {
458 ChoiceFormat other = (ChoiceFormat) super.clone();
459 // for primitives or immutables, shallow clone is enough
460 other.choiceLimits = (double[]) choiceLimits.clone();
461 other.choiceFormats = (String[]) choiceFormats.clone();
462 return other;
463 }
464
465 /**
466 * Generates a hash code for the message format object.
467 */
468 public int hashCode() {
469 int result = choiceLimits.length;
470 if (choiceFormats.length > 0) {
471 // enough for reasonable distribution
472 result ^= choiceFormats[choiceFormats.length-1].hashCode();
473 }
474 return result;
475 }
476
477 /**
478 * Equality comparision between two
479 */
480 public boolean equals(Object obj) {
481 if (obj == null) return false;
482 if (this == obj) // quick check
483 return true;
484 if (getClass() != obj.getClass())
485 return false;
486 ChoiceFormat other = (ChoiceFormat) obj;
487 return (Arrays.equals(choiceLimits, other.choiceLimits)
488 && Arrays.equals(choiceFormats, other.choiceFormats));
489 }
490
491 /**
492 * After reading an object from the input stream, do a simple verification
493 * to maintain class invariants.
494 * @throws InvalidObjectException if the objects read from the stream is invalid.
495 */
496 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
497 in.defaultReadObject();
498 if (choiceLimits.length != choiceFormats.length) {
499 throw new InvalidObjectException(
500 "limits and format arrays of different length.");
501 }
502 }
503
504 // ===============privates===========================
505
506 /**
507 * A list of lower bounds for the choices. The formatter will return
508 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
509 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
510 * @serial
511 */
512 private double[] choiceLimits;
513
514 /**
515 * A list of choice strings. The formatter will return
516 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
517 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
518 * @serial
519 */
520 private String[] choiceFormats;
521
522 /*
523 static final long SIGN = 0x8000000000000000L;
524 static final long EXPONENT = 0x7FF0000000000000L;
525 static final long SIGNIFICAND = 0x000FFFFFFFFFFFFFL;
526
527 private static double nextDouble (double d, boolean positive) {
528 if (Double.isNaN(d) || Double.isInfinite(d)) {
529 return d;
530 }
531 long bits = Double.doubleToLongBits(d);
532 long significand = bits & SIGNIFICAND;
533 if (bits < 0) {
534 significand |= (SIGN | EXPONENT);
535 }
536 long exponent = bits & EXPONENT;
537 if (positive) {
538 significand += 1;
539 // FIXME fix overflow & underflow
540 } else {
541 significand -= 1;
542 // FIXME fix overflow & underflow
543 }
544 bits = exponent | (significand & ~EXPONENT);
545 return Double.longBitsToDouble(bits);
546 }
547 */
548
549 static final long SIGN = 0x8000000000000000L;
550 static final long EXPONENT = 0x7FF0000000000000L;
551 static final long POSITIVEINFINITY = 0x7FF0000000000000L;
552
553 /**
554 * Finds the least double greater than d (if positive == true),
555 * or the greatest double less than d (if positive == false).
556 * If NaN, returns same value.
557 *
558 * Does not affect floating-point flags,
559 * provided these member functions do not:
560 * Double.longBitsToDouble(long)
561 * Double.doubleToLongBits(double)
562 * Double.isNaN(double)
563 */
564 public static double nextDouble (double d, boolean positive) {
565
566 /* filter out NaN's */
567 if (Double.isNaN(d)) {
568 return d;
569 }
570
571 /* zero's are also a special case */
572 if (d == 0.0) {
573 double smallestPositiveDouble = Double.longBitsToDouble(1L);
574 if (positive) {
575 return smallestPositiveDouble;
576 } else {
577 return -smallestPositiveDouble;
578 }
579 }
580
581 /* if entering here, d is a nonzero value */
582
583 /* hold all bits in a long for later use */
584 long bits = Double.doubleToLongBits(d);
585
586 /* strip off the sign bit */
587 long magnitude = bits & ~SIGN;
588
589 /* if next double away from zero, increase magnitude */
590 if ((bits > 0) == positive) {
591 if (magnitude != POSITIVEINFINITY) {
592 magnitude += 1;
593 }
594 }
595 /* else decrease magnitude */
596 else {
597 magnitude -= 1;
598 }
599
600 /* restore sign bit and return */
601 long signbit = bits & SIGN;
602 return Double.longBitsToDouble (magnitude | signbit);
603 }
604
605 private static double[] doubleArraySize(double[] array) {
606 int oldSize = array.length;
607 double[] newArray = new double[oldSize * 2];
608 System.arraycopy(array, 0, newArray, 0, oldSize);
609 return newArray;
610 }
611
612 private String[] doubleArraySize(String[] array) {
613 int oldSize = array.length;
614 String[] newArray = new String[oldSize * 2];
615 System.arraycopy(array, 0, newArray, 0, oldSize);
616 return newArray;
617 }
618
619 }
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