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 constructor. | |
~FieldPosition () | |
Destructor . | |
FieldPosition & | operator= (const FieldPosition ©) |
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. |
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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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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Creates a FieldPosition object with a non-specified field.
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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.
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Copy constructor.
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Retrieve the index of the first character in the requested field.
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Retrieve the index of the character following the last character in the requested field.
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Retrieve the field identifier.
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Equality operator.
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Equality operator.
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Set the begin index. For use by subclasses of Format. |
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Set the end index. For use by subclasses of Format. |
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Set the field.
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