FieldPosition Class Reference

FieldPosition is a simple class used by Format and its subclasses to identify fields in formatted output. More...

#include <fieldpos.h>

Public Types
enum	{ DONT_CARE = -1 }
	DONT_CARE may be specified as the field to indicate that the caller doesn't need to specify a field. More...
Public Member Functions
	FieldPosition ()
	Creates a FieldPosition object with a non-specified field.
	FieldPosition (int32_t field)
	Creates a FieldPosition object for the given field.
	FieldPosition (const FieldPosition &copy)
	Copy constructor.
	~FieldPosition ()
	Destructor .
FieldPosition &	operator= (const FieldPosition &copy)
	Assignment operator .
UBool	operator== (const FieldPosition &that) const
	Equality operator.
UBool	operator!= (const FieldPosition &that) const
	Equality operator.
int32_t	getField (void) const
	Retrieve the field identifier.
int32_t	getBeginIndex (void) const
	Retrieve the index of the first character in the requested field.
int32_t	getEndIndex (void) const
	Retrieve the index of the character following the last character in the requested field.
void	setField (int32_t f)
	Set the field.
void	setBeginIndex (int32_t bi)
	Set the begin index.
void	setEndIndex (int32_t ei)
	Set the end index.

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Detailed Description

FieldPosition is a simple class used by Format and its subclasses to identify fields in formatted output.

Fields are identified by constants, whose names typically end with _FIELD, defined in the various subclasses of Format. See ERA_FIELD and its friends in DateFormat for an example.

FieldPosition keeps track of the position of the field within the formatted output with two indices: the index of the first character of the field and the index of the last character of the field.

One version of the format method in the various Format classes requires a FieldPosition object as an argument. You use this format method to perform partial formatting or to get information about the formatted output (such as the position of a field).

Below is an example of using FieldPosition to aid alignment of an array of formatted floating-point numbers on their decimal points:

 
       double doubleNum[] = {123456789.0, -12345678.9, 1234567.89, -123456.789,
                  12345.6789, -1234.56789, 123.456789, -12.3456789, 1.23456789};
       int dNumSize = (int)(sizeof(doubleNum)/sizeof(double));
       
       UErrorCode status = U_ZERO_ERROR;
       DecimalFormat* fmt = (DecimalFormat*) NumberFormat::createInstance(status);
       fmt->setDecimalSeparatorAlwaysShown(true);
       
       const int tempLen = 20;
       char temp[tempLen];
       
       for (int i=0; i<dNumSize; i++) {
           FieldPosition pos(NumberFormat::INTEGER_FIELD);
           UnicodeString buf;
           char fmtText[tempLen];
           ToCharString(fmt->format(doubleNum[i], buf, pos), fmtText);
           for (int j=0; j<tempLen; j++) temp[j] = ' '; // clear with spaces
           temp[__min(tempLen, tempLen-pos.getEndIndex())] = '\0';
           cout << temp << fmtText   << endl;
       }
       delete fmt;

 

The code will generate the following output:

 
           123,456,789.000
           -12,345,678.900
             1,234,567.880
              -123,456.789
                12,345.678
                -1,234.567
                   123.456
                   -12.345
                     1.234

 

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Member Enumeration Documentation

anonymous enum

DONT_CARE may be specified as the field to indicate that the caller doesn't need to specify a field. Do not subclass.

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Constructor & Destructor Documentation

FieldPosition::FieldPosition (   )  [inline]

Creates a FieldPosition object with a non-specified field.

FieldPosition::FieldPosition (  int32_t  field  )  [inline]

Creates a FieldPosition object for the given field. Fields are identified by constants, whose names typically end with _FIELD, in the various subclasses of Format. See also: NumberFormat::INTEGER_FIELD NumberFormat#FRACTION_FIELD DateFormat#YEAR_FIELD DateFormat#MONTH_FIELD

FieldPosition::FieldPosition (  const FieldPosition &  copy  )  [inline]

Copy constructor. Parameters: copy  the object to be copied from.

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Member Function Documentation

int32_t FieldPosition::getBeginIndex (  void   )  const [inline]

Retrieve the index of the first character in the requested field.

int32_t FieldPosition::getEndIndex (  void   )  const [inline]

Retrieve the index of the character following the last character in the requested field.

int32_t FieldPosition::getField (  void   )  const [inline]

Retrieve the field identifier.

UBool FieldPosition::operator!= (  const FieldPosition &  that  )  const [inline]

Equality operator. Returns: TRUE if the two field positions are not equal, FALSE otherwise.

UBool FieldPosition::operator== (  const FieldPosition &  that  )  const [inline]

Equality operator. Returns: TRUE if the two field positions are equal, FALSE otherwise.

void FieldPosition::setBeginIndex (  int32_t  bi  )  [inline]

Set the begin index. For use by subclasses of Format.

void FieldPosition::setEndIndex (  int32_t  ei  )  [inline]

Set the end index. For use by subclasses of Format.

void FieldPosition::setField (  int32_t  f  )  [inline]

Set the field.

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The documentation for this class was generated from the following file:

• fieldpos.h

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