java.text
Class ChoiceFormat
java.lang.Object
|
+--java.text.Format
|
+--java.text.NumberFormat
|
+--java.text.ChoiceFormat
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
i
will be selected for value
X
if
terminator[i] <= X < limit[i + 1]
. 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.
This sounds complicated, but that is because I did a poor job of
explaining it. Consider the following example:
terminators = { 1, ChoiceFormat.nextDouble(1) }
formats = { "file", "files" }
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 nextDouble
. 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.
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.
Authors:- Tom Tromey <tromey@cygnus.com>
- Aaron M. Renn (arenn@urbanophile.com)
ChoiceFormat
public ChoiceFormat(double[] choiceLimits, java.lang.String[] choiceFormats)
This method initializes a new instance of ChoiceFormat
that
will use the specified range terminators and format strings.
Parameters:
ChoiceFormat
public ChoiceFormat(java.lang.String newPattern)
This method initializes a new instance of ChoiceFormat
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 applyPattern
method.
Parameters:
Throws:
applyPattern
public void applyPattern(java.lang.String newPattern)
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".
Parameters:
Throws:
equals
public boolean equals(java.lang.Object obj)
This method tests this object for equality with the specified
object. This will be true if and only if:
- The specified object is not
null
.
- The specified object is an instance of
ChoiceFormat
.
- The termination ranges and format strings are identical to
this object's.
Parameters:
Returns:
true
if the specified object is equal to
this one, false
otherwise.
format
public StringBuffer format(double num, java.lang.StringBuffer appendBuf, java.text.FieldPosition pos)
This method appends the appropriate format string to the specified
StringBuffer
based on the supplied double
argument.
Parameters:
Returns:
- The
StringBuffer
with the format string appended.
format
public StringBuffer format(long num, java.lang.StringBuffer appendBuf, java.text.FieldPosition pos)
This method appends the appropriate format string to the specified
StringBuffer
based on the supplied long
argument.
Parameters:
Returns:
- The
StringBuffer
with the format string appended.
getFormats
public Object[] getFormats()
This method returns the list of format strings in use.
Returns:
- The list of format objects.
getLimits
public double[] getLimits()
This method returns the list of range terminators in use.
Returns:
- The list of range terminators.
hashCode
public int hashCode()
This method returns a hash value for this object
Returns:
- A hash value for this object.
nextDouble
public static final double nextDouble(double d)
This method returns the lowest possible double greater than the
specified double. If the specified double value is equal to
Double.NaN
then that is the value returned.
Parameters:
Returns:
- The lowest double value greater than the specified double.
nextDouble
public static double nextDouble(double d, boolean next)
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
true
, 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.
Parameters:
Returns:
- The next highest or lowest double value.
parse
public Number parse(java.lang.String sourceStr, java.text.ParsePosition pos)
I'm not sure what this method is really supposed to do, as it is
not documented.
Parameters:
previousDouble
public static final double previousDouble(double d)
This method returns the highest possible double less than the
specified double. If the specified double value is equal to
Double.NaN
then that is the value returned.
Parameters:
Returns:
- The highest double value less than the specified double.
setChoices
public void setChoices(double[] choiceLimits, java.lang.String[] choiceFormats)
This method sets new range terminators and format strings for this
object.
Parameters:
toPattern
public String toPattern()
This method returns the range terminator list and format string list
as a String
suitable for using with the
applyPattern
method.
Returns:
- A pattern string for this object
i
will be selected for valueX
ifterminator[i] <= X < limit[i + 1]
. 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.This sounds complicated, but that is because I did a poor job of explaining it. Consider the following example:
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
nextDouble
. 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.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.