FieldPosition Class Reference

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

#include <fieldpos.h>

Inheritance diagram for FieldPosition:
UObject UMemory

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.
virtual ~FieldPosition ()
 Destructor.
FieldPositionoperator= (const FieldPosition &copy)
 Assignment operator.
UBool operator== (const FieldPosition &that) const
 Equality operator.
UBool operator!= (const FieldPosition &that) const
 Equality operator.
FieldPositionclone () const
 Clone this object.
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.
virtual UClassID getDynamicClassID () const
 ICU "poor man's RTTI", returns a UClassID for the actual class.

Static Public Member Functions

static UClassID getStaticClassID ()
 ICU "poor man's RTTI", returns a UClassID for this class.

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).

The FieldPosition class is not suitable for subclassing.

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

Definition at line 106 of file fieldpos.h.


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.

Definition at line 112 of file fieldpos.h.


Constructor & Destructor Documentation

FieldPosition::FieldPosition (  )  [inline]

Creates a FieldPosition object with a non-specified field.

Stable:
ICU 2.0

Definition at line 118 of file fieldpos.h.

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
Stable:
ICU 2.0

Definition at line 132 of file fieldpos.h.

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

Copy constructor.

Parameters:
copy the object to be copied from.
Stable:
ICU 2.0

Definition at line 140 of file fieldpos.h.

virtual FieldPosition::~FieldPosition (  )  [virtual]

Destructor.

Stable:
ICU 2.0

Member Function Documentation

FieldPosition* FieldPosition::clone (  )  const

Clone this object.

Clones can be used concurrently in multiple threads. If an error occurs, then NULL is returned. The caller must delete the clone.

Returns:
a clone of this object
See also:
getDynamicClassID
Stable:
ICU 2.8
int32_t FieldPosition::getBeginIndex ( void   )  const [inline]

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

Returns:
the index of the first character in the requested field.
Stable:
ICU 2.0

Definition at line 197 of file fieldpos.h.

virtual UClassID FieldPosition::getDynamicClassID (  )  const [virtual]

ICU "poor man's RTTI", returns a UClassID for the actual class.

Stable:
ICU 2.2

Implements UObject.

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

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

Returns:
the index of the character following the last character in the requested field.
Stable:
ICU 2.0

Definition at line 206 of file fieldpos.h.

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

Retrieve the field identifier.

Returns:
the field identifier.
Stable:
ICU 2.0

Definition at line 190 of file fieldpos.h.

static UClassID FieldPosition::getStaticClassID (  )  [static]

ICU "poor man's RTTI", returns a UClassID for this class.

Stable:
ICU 2.2
UBool FieldPosition::operator!= ( const FieldPosition that  )  const [inline]

Equality operator.

Parameters:
that the object to be compared with.
Returns:
TRUE if the two field positions are not equal, FALSE otherwise.
Stable:
ICU 2.0

Definition at line 281 of file fieldpos.h.

References operator==().

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

Assignment operator.

Parameters:
copy the object to be copied from.
Stable:
ICU 2.0

Definition at line 264 of file fieldpos.h.

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

Equality operator.

Parameters:
that the object to be compared with.
Returns:
TRUE if the two field positions are equal, FALSE otherwise.
Stable:
ICU 2.0

Definition at line 273 of file fieldpos.h.

Referenced by operator!=().

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

Set the begin index.

For use by subclasses of Format.

Parameters:
bi the new value of the begin index
Stable:
ICU 2.0

Definition at line 220 of file fieldpos.h.

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

Set the end index.

For use by subclasses of Format.

Parameters:
ei the new value of the end index
Stable:
ICU 2.0

Definition at line 227 of file fieldpos.h.

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

Set the field.

Parameters:
f the new value of the field.
Stable:
ICU 2.0

Definition at line 213 of file fieldpos.h.


The documentation for this class was generated from the following file:
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Generated on Sat Jan 23 15:17:42 2010 for ICU 4.3.4 by  doxygen 1.6.1