class FieldPosition
Defined at line 110 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
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 intended for public subclassing.
Below is an example of using
FieldPosition
to aid
alignment of an array of formatted floating-point numbers on
their decimal points:
The code will generate the following output:
Code
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;
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
Public Methods
void FieldPosition ()Creates a FieldPosition object with a non-specified field.
ICU 2.0
Defined at line 123 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
void FieldPosition (int32_t field)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.
Defined at line 137 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
void FieldPosition (const FieldPosition & copy)Copy constructor
Parameters
Defined at line 145 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
void ~FieldPosition ()Destructor
ICU 2.0
FieldPosition & operator= (const FieldPosition & copy)Assignment operator
Parameters
Defined at line 268 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
bool operator== (const FieldPosition & that)Equality operator.
Parameters
Returns
true if the two field positions are equal, false otherwise.
ICU 2.0
Defined at line 277 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
bool operator!= (const FieldPosition & that)Equality operator.
Parameters
Returns
true if the two field positions are not equal, false otherwise.
ICU 2.0
Defined at line 285 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
FieldPosition * clone ()Clone this object.
Clones can be used concurrently in multiple threads.
If an error occurs, then nullptr is returned.
The caller must delete the clone.
Returns
a clone of this object
int32_t getField ()Retrieve the field identifier.
Returns
the field identifier.
ICU 2.0
Defined at line 195 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
int32_t getBeginIndex ()Retrieve the index of the first character in the requested field.
Returns
the index of the first character in the requested field.
ICU 2.0
Defined at line 202 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
UClassID getDynamicClassID ()ICU "poor man's RTTI", returns a UClassID for the actual class.
ICU 2.2
int32_t getEndIndex ()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.
ICU 2.0
Defined at line 211 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
UClassID getStaticClassID ()ICU "poor man's RTTI", returns a UClassID for this class.
ICU 2.2
void setField (int32_t f)Set the field.
Parameters
Defined at line 218 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
void setBeginIndex (int32_t bi)Set the begin index. For use by subclasses of Format.
Parameters
Defined at line 225 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
void setEndIndex (int32_t ei)Set the end index. For use by subclasses of Format.
Parameters
Defined at line 232 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h
Enumerations
enum | Name | Value |
|---|---|
| DONT_CARE | -1 |
DONT_CARE may be specified as the field to indicate that the
caller doesn't need to specify a field.
ICU 2.0
Defined at line 117 of file ../../third_party/icu/latest/source/i18n/unicode/fieldpos.h