505 lines
15 KiB
Java
505 lines
15 KiB
Java
/* ChoiceFormat.java -- Format over a range of numbers
|
|
Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.text;
|
|
|
|
import java.util.Vector;
|
|
|
|
/**
|
|
* This class allows a format to be specified based on a range of numbers.
|
|
* To use this class, first specify two lists of formats and range terminators.
|
|
* These lists must be arrays of equal length. The format of index
|
|
* <code>i</code> will be selected for value <code>X</code> if
|
|
* <code>terminator[i] <= X < limit[i + 1]</code>. If the value X is not
|
|
* included in any range, then either the first or last format will be
|
|
* used depending on whether the value X falls outside the range.
|
|
* <p>
|
|
* This sounds complicated, but that is because I did a poor job of
|
|
* explaining it. Consider the following example:
|
|
* <p>
|
|
* <pre>
|
|
* terminators = { 1, ChoiceFormat.nextDouble(1) }
|
|
* formats = { "file", "files" }
|
|
* </pre>
|
|
* <p>
|
|
* In this case if the actual number tested is one or less, then the word
|
|
* "file" is used as the format value. If the number tested is greater than
|
|
* one, then "files" is used. This allows plurals to be handled
|
|
* gracefully. Note the use of the method <code>nextDouble</code>. This
|
|
* method selects the next highest double number than its argument. This
|
|
* effectively makes any double greater than 1.0 cause the "files" string
|
|
* to be selected. (Note that all terminator values are specified as
|
|
* doubles.
|
|
* <p>
|
|
* Note that in order for this class to work properly, the range terminator
|
|
* array must be sorted in ascending order and the format string array
|
|
* must be the same length as the terminator array.
|
|
*
|
|
* @author Tom Tromey <tromey@cygnus.com>
|
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
|
* @date March 9, 1999
|
|
*/
|
|
/* Written using "Java Class Libraries", 2nd edition, plus online
|
|
* API docs for JDK 1.2 from http://www.javasoft.com.
|
|
* Status: Believed complete and correct to 1.1.
|
|
*/
|
|
public class ChoiceFormat extends NumberFormat
|
|
{
|
|
/**
|
|
* This method sets new range terminators and format strings for this
|
|
* object based on the specified pattern. This pattern is of the form
|
|
* "term#string|term#string...". For example "1#Sunday|2#Monday|#Tuesday".
|
|
*
|
|
* @param pattern The pattern of terminators and format strings.
|
|
*
|
|
* @exception IllegalArgumentException If the pattern is not valid
|
|
*/
|
|
public void applyPattern (String newPattern)
|
|
{
|
|
// Note: we assume the same kind of quoting rules apply here.
|
|
// This isn't explicitly documented. But for instance we accept
|
|
// '#' as a literal hash in a format string.
|
|
int index = 0, max = newPattern.length();
|
|
Vector stringVec = new Vector ();
|
|
Vector limitVec = new Vector ();
|
|
StringBuffer buf = new StringBuffer ();
|
|
|
|
while (true)
|
|
{
|
|
// Find end of double.
|
|
int dstart = index;
|
|
while (index < max)
|
|
{
|
|
char c = newPattern.charAt(index);
|
|
if (c == '#' || c == '\u2064' || c == '<')
|
|
break;
|
|
++index;
|
|
}
|
|
|
|
if (index == max)
|
|
throw new IllegalArgumentException ("unexpected end of text");
|
|
Double d = new Double (newPattern.substring(dstart, index));
|
|
|
|
if (newPattern.charAt(index) == '<')
|
|
d = new Double (nextDouble (d.doubleValue()));
|
|
|
|
limitVec.addElement(d);
|
|
|
|
// Scan text.
|
|
++index;
|
|
buf.setLength(0);
|
|
while (index < max)
|
|
{
|
|
char c = newPattern.charAt(index);
|
|
if (c == '\'' && index < max + 1
|
|
&& newPattern.charAt(index + 1) == '\'')
|
|
{
|
|
buf.append(c);
|
|
++index;
|
|
}
|
|
else if (c == '\'' && index < max + 2)
|
|
{
|
|
buf.append(newPattern.charAt(index + 1));
|
|
index += 2;
|
|
}
|
|
else if (c == '|')
|
|
break;
|
|
else
|
|
buf.append(c);
|
|
++index;
|
|
}
|
|
|
|
stringVec.addElement(buf.toString());
|
|
if (index == max)
|
|
break;
|
|
++index;
|
|
}
|
|
|
|
choiceFormats = new String[stringVec.size()];
|
|
stringVec.copyInto(choiceFormats);
|
|
|
|
choiceLimits = new double[limitVec.size()];
|
|
for (int i = 0; i < choiceLimits.length; ++i)
|
|
{
|
|
Double d = (Double) limitVec.elementAt(i);
|
|
choiceLimits[i] = d.doubleValue();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method initializes a new instance of <code>ChoiceFormat</code> that
|
|
* generates its range terminator and format string arrays from the
|
|
* specified pattern. This pattern is of the form
|
|
* "term#string|term#string...". For example "1#Sunday|2#Monday|#Tuesday".
|
|
* This is the same pattern type used by the <code>applyPattern</code>
|
|
* method.
|
|
*
|
|
* @param pattern The pattern of terminators and format strings.
|
|
*
|
|
* @exception IllegalArgumentException If the pattern is not valid
|
|
*/
|
|
public ChoiceFormat (String newPattern)
|
|
{
|
|
super ();
|
|
applyPattern (newPattern);
|
|
}
|
|
|
|
/**
|
|
* This method initializes a new instance of <code>ChoiceFormat</code> that
|
|
* will use the specified range terminators and format strings.
|
|
*
|
|
* @param choiceLimits The array of range terminators
|
|
* @param choiceFormats The array of format strings
|
|
*/
|
|
public ChoiceFormat (double[] choiceLimits, String[] choiceFormats)
|
|
{
|
|
super ();
|
|
setChoices (choiceLimits, choiceFormats);
|
|
}
|
|
|
|
/**
|
|
* This method tests this object for equality with the specified
|
|
* object. This will be true if and only if:
|
|
* <ul>
|
|
* <li>The specified object is not <code>null</code>.
|
|
* <li>The specified object is an instance of <code>ChoiceFormat</code>.
|
|
* <li>The termination ranges and format strings are identical to
|
|
* this object's.
|
|
* </ul>
|
|
*
|
|
* @param obj The object to test for equality against.
|
|
*
|
|
* @return <code>true</code> if the specified object is equal to
|
|
* this one, <code>false</code> otherwise.
|
|
*/
|
|
public boolean equals (Object obj)
|
|
{
|
|
if (! (obj instanceof ChoiceFormat))
|
|
return false;
|
|
ChoiceFormat cf = (ChoiceFormat) obj;
|
|
if (choiceLimits.length != cf.choiceLimits.length)
|
|
return false;
|
|
for (int i = choiceLimits.length - 1; i >= 0; --i)
|
|
{
|
|
if (choiceLimits[i] != cf.choiceLimits[i]
|
|
|| !choiceFormats[i].equals(cf.choiceFormats[i]))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* This method appends the appropriate format string to the specified
|
|
* <code>StringBuffer</code> based on the supplied <code>long</code>
|
|
* argument.
|
|
*
|
|
* @param number The number used for determine (based on the range
|
|
* terminators) which format string to append.
|
|
* @param sb The <code>StringBuffer</code> to append the format string to.
|
|
* @param status Unused.
|
|
*
|
|
* @return The <code>StringBuffer</code> with the format string appended.
|
|
*/
|
|
public StringBuffer format (long num, StringBuffer appendBuf,
|
|
FieldPosition pos)
|
|
{
|
|
return format ((double) num, appendBuf, pos);
|
|
}
|
|
|
|
/**
|
|
* This method appends the appropriate format string to the specified
|
|
* <code>StringBuffer</code> based on the supplied <code>double</code>
|
|
* argument.
|
|
*
|
|
* @param number The number used for determine (based on the range
|
|
* terminators) which format string to append.
|
|
* @param sb The <code>StringBuffer</code> to append the format string to.
|
|
* @param status Unused.
|
|
*
|
|
* @return The <code>StringBuffer</code> with the format string appended.
|
|
*/
|
|
public StringBuffer format (double num, StringBuffer appendBuf,
|
|
FieldPosition pos)
|
|
{
|
|
if (choiceLimits.length == 0)
|
|
return appendBuf;
|
|
|
|
int index = 0;
|
|
if (! Double.isNaN(num) && num >= choiceLimits[0])
|
|
{
|
|
for (; index < choiceLimits.length - 1; ++index)
|
|
{
|
|
if (choiceLimits[index] <= num
|
|
&& index != choiceLimits.length - 2
|
|
&& num < choiceLimits[index + 1])
|
|
break;
|
|
}
|
|
}
|
|
|
|
return appendBuf.append(choiceFormats[index]);
|
|
}
|
|
|
|
/**
|
|
* This method returns the list of format strings in use.
|
|
*
|
|
* @return The list of format objects.
|
|
*/
|
|
public Object[] getFormats ()
|
|
{
|
|
return (Object[]) choiceFormats.clone();
|
|
}
|
|
|
|
/**
|
|
* This method returns the list of range terminators in use.
|
|
*
|
|
* @return The list of range terminators.
|
|
*/
|
|
public double[] getLimits ()
|
|
{
|
|
return (double[]) choiceLimits.clone();
|
|
}
|
|
|
|
/**
|
|
* This method returns a hash value for this object
|
|
*
|
|
* @return A hash value for this object.
|
|
*/
|
|
public int hashCode ()
|
|
{
|
|
int hash = 0;
|
|
for (int i = 0; i < choiceLimits.length; ++i)
|
|
{
|
|
long v = Double.doubleToLongBits(choiceLimits[i]);
|
|
hash ^= (v ^ (v >>> 32));
|
|
hash ^= choiceFormats[i].hashCode();
|
|
}
|
|
return hash;
|
|
}
|
|
|
|
/**
|
|
* This method returns the lowest possible double greater than the
|
|
* specified double. If the specified double value is equal to
|
|
* <code>Double.NaN</code> then that is the value returned.
|
|
*
|
|
* @param d The specified double
|
|
*
|
|
* @return The lowest double value greater than the specified double.
|
|
*/
|
|
public static final double nextDouble (double d)
|
|
{
|
|
return nextDouble (d, true);
|
|
}
|
|
|
|
/**
|
|
* This method returns a double that is either the next highest double
|
|
* or next lowest double compared to the specified double depending on the
|
|
* value of the passed boolean parameter. If the boolean parameter is
|
|
* <code>true</code>, then the lowest possible double greater than the
|
|
* specified double will be returned. Otherwise the highest possible
|
|
* double less than the specified double will be returned.
|
|
*
|
|
* @param d The specified double
|
|
* @param positive <code>true</code> to return the next highest
|
|
* double, <code>false</code> otherwise.
|
|
*
|
|
* @return The next highest or lowest double value.
|
|
*/
|
|
public static double nextDouble (double d, boolean next)
|
|
{
|
|
if (Double.isInfinite(d) || Double.isNaN(d))
|
|
return d;
|
|
|
|
long bits = Double.doubleToLongBits(d);
|
|
|
|
long mantMask = (1L << mantissaBits) - 1;
|
|
long mantissa = bits & mantMask;
|
|
|
|
long expMask = (1L << exponentBits) - 1;
|
|
long exponent = (bits >>> mantissaBits) & expMask;
|
|
|
|
if (next ^ (bits < 0)) // Increment magnitude
|
|
{
|
|
if (mantissa == (1L << mantissaBits) - 1)
|
|
{
|
|
mantissa = 0L;
|
|
exponent++;
|
|
|
|
// Check for absolute overflow.
|
|
if (exponent >= (1L << mantissaBits))
|
|
return (bits > 0) ? Double.POSITIVE_INFINITY
|
|
: Double.NEGATIVE_INFINITY;
|
|
}
|
|
else
|
|
mantissa++;
|
|
}
|
|
else // Decrement magnitude
|
|
{
|
|
if (exponent == 0L && mantissa == 0L)
|
|
{
|
|
// The only case where there is a change of sign
|
|
return next ? Double.MIN_VALUE : -Double.MIN_VALUE;
|
|
}
|
|
else
|
|
{
|
|
if (mantissa == 0L)
|
|
{
|
|
mantissa = (1L << mantissaBits) - 1;
|
|
exponent--;
|
|
}
|
|
else
|
|
mantissa--;
|
|
}
|
|
}
|
|
|
|
long result = bits < 0 ? 1 : 0;
|
|
result = (result << exponentBits) | exponent;
|
|
result = (result << mantissaBits) | mantissa;
|
|
return Double.longBitsToDouble(result);
|
|
}
|
|
|
|
/**
|
|
* I'm not sure what this method is really supposed to do, as it is
|
|
* not documented.
|
|
*/
|
|
public Number parse (String sourceStr, ParsePosition pos)
|
|
{
|
|
int index = pos.getIndex();
|
|
for (int i = 0; i < choiceLimits.length; ++i)
|
|
{
|
|
if (sourceStr.startsWith(choiceFormats[i], index))
|
|
{
|
|
pos.setIndex(index + choiceFormats[i].length());
|
|
return new Double (choiceLimits[i]);
|
|
}
|
|
}
|
|
pos.setErrorIndex(index);
|
|
return new Double (Double.NaN);
|
|
}
|
|
|
|
/**
|
|
* This method returns the highest possible double less than the
|
|
* specified double. If the specified double value is equal to
|
|
* <code>Double.NaN</code> then that is the value returned.
|
|
*
|
|
* @param d The specified double
|
|
*
|
|
* @return The highest double value less than the specified double.
|
|
*/
|
|
public static final double previousDouble (double d)
|
|
{
|
|
return nextDouble (d, false);
|
|
}
|
|
|
|
/**
|
|
* This method sets new range terminators and format strings for this
|
|
* object.
|
|
*
|
|
* @param choiceLimits The new range terminators
|
|
* @param choiceFormats The new choice formats
|
|
*/
|
|
public void setChoices (double[] choiceLimits, String[] choiceFormats)
|
|
{
|
|
if (choiceLimits == null || choiceFormats == null)
|
|
throw new NullPointerException ();
|
|
if (choiceLimits.length != choiceFormats.length)
|
|
throw new IllegalArgumentException ();
|
|
this.choiceFormats = (String[]) choiceFormats.clone();
|
|
this.choiceLimits = (double[]) choiceLimits.clone();
|
|
}
|
|
|
|
private final void quoteString (StringBuffer dest, String text)
|
|
{
|
|
int max = text.length();
|
|
for (int i = 0; i < max; ++i)
|
|
{
|
|
char c = text.charAt(i);
|
|
if (c == '\'')
|
|
{
|
|
dest.append(c);
|
|
dest.append(c);
|
|
}
|
|
else if (c == '#' || c == '|' || c == '\u2064' || c == '<')
|
|
{
|
|
dest.append('\'');
|
|
dest.append(c);
|
|
dest.append('\'');
|
|
}
|
|
else
|
|
dest.append(c);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method returns the range terminator list and format string list
|
|
* as a <code>String</code> suitable for using with the
|
|
* <code>applyPattern</code> method.
|
|
*
|
|
* @return A pattern string for this object
|
|
*/
|
|
public String toPattern ()
|
|
{
|
|
StringBuffer result = new StringBuffer ();
|
|
for (int i = 0; i < choiceLimits.length; ++i)
|
|
{
|
|
result.append(choiceLimits[i]);
|
|
result.append('#');
|
|
quoteString (result, choiceFormats[i]);
|
|
}
|
|
return result.toString();
|
|
}
|
|
|
|
/**
|
|
* This is the list of format strings. Note that this variable is
|
|
* specified by the serialization spec of this class.
|
|
*/
|
|
private String[] choiceFormats;
|
|
|
|
/**
|
|
* This is the list of range terminator values. Note that this variable is
|
|
* specified by the serialization spec of this class.
|
|
*/
|
|
private double[] choiceLimits;
|
|
|
|
// Number of mantissa bits in double.
|
|
private static final int mantissaBits = 52;
|
|
// Number of exponent bits in a double.
|
|
private static final int exponentBits = 11;
|
|
|
|
private static final long serialVersionUID = 1795184449645032964L;
|
|
}
|