gecko-dev/modules/libnls/headers/numfmt.h
1998-05-27 02:02:27 +00:00

488 lines
18 KiB
C++

/*
********************************************************************************
* *
* COPYRIGHT: *
* (C) Copyright Taligent, Inc., 1997 *
* (C) Copyright International Business Machines Corporation, 1997 *
* Licensed Material - Program-Property of IBM - All Rights Reserved. *
* US Government Users Restricted Rights - Use, duplication, or disclosure *
* restricted by GSA ADP Schedule Contract with IBM Corp. *
* *
********************************************************************************
*
* File NUMFMT.H
*
* Modification History:
*
* Date Name Description
* 02/19/97 aliu Converted from java.
* 03/18/97 clhuang Updated per C++ implementation.
* 04/17/97 aliu Changed DigitCount to int per code review.
********************************************************************************
*/
#ifndef _NUMFMT
#define _NUMFMT
#include "ptypes.h"
#include "unistring.h"
#include "format.h"
class Locale;
/**
* Abstract base class for all number formats. Provides interface for
* formatting and parsing a number. Also provides methods for
* determining which locales have number formats, and what their names
* are.
* <P>
* NumberFormat helps you to format and parse numbers for any locale.
* Your code can be completely independent of the locale conventions
* for decimal points, thousands-separators, or even the particular
* decimal digits used, or whether the number format is even decimal.
* <P>
* To format a number for the current Locale, use one of the static
* factory methods:
* <pre>
* . double myNumber;
* . UnicodeString myString;
* . NumberFormat::createInstance()->format(myNumber, myString);
* </pre>
* If you are formatting multiple numbers, it is more efficient to get
* the format and use it multiple times so that the system doesn't
* have to fetch the information about the local language and country
* conventions multiple times.
* <pre>
* . NumberFormat* nf = NumberFormat::createInstance();
* . UnicodeString myString;
* . long a[a_length];
* . for (int i = 0; i &lt; a_length; ++i) {
* . cout &lt;&lt; nf->format(a[i], myString) &lt;&lt; "; ";
* . }
* </pre>
* To format a number for a different Locale, specify it in the
* call to createInstance().
* <pre>
* . NumberFormat* nf = NumberFormat::createInstance(Locale::FRENCH);
* </pre>
* You can use a NumberFormat to parse also.
* <pre>
* . ErrorCode status;
* . Formattable myNumber(999);
* . nf->parse(myString, myNumber, status);
* </pre>
* Use createInstance to get the normal number format for that country.
* There are other static factory methods available. Use getCurrency
* to get the currency number format for that country. Use getPercent
* to get a format for displaying percentages. With this format, a
* fraction from 0.53 is displayed as 53%.
* <P>
* You can also control the display of numbers with such methods as
* getMinimumFractionDigits. If you want even more control over the
* format or parsing, or want to give your users more control, you can
* try casting the NumberFormat you get from the factory methods to a
* DecimalNumberFormat. This will work for the vast majority of
* countries; just remember to put it in a try block in case you
* encounter an unusual one.
* <P>
* You can also use forms of the parse and format methods with
* ParsePosition and FieldPosition to allow you to:
* <ul type=round>
* <li>(a) progressively parse through pieces of a string.
* <li>(b) align the decimal point and other areas.
* </ul>
* For example, you can align numbers in two ways.
* <P>
* If you are using a monospaced font with spacing for alignment, you
* can pass the FieldPosition in your format call, with field =
* INTEGER_FIELD. On output, getEndIndex will be set to the offset
* between the last character of the integer and the decimal. Add
* (desiredSpaceCount - getEndIndex) spaces at the front of the
* string.
* <P>
* If you are using proportional fonts, instead of padding with
* spaces, measure the width of the string in pixels from the start to
* getEndIndex. Then move the pen by (desiredPixelWidth -
* widthToAlignmentPoint) before drawing the text. It also works
* where there is no decimal, but possibly additional characters at
* the end, e.g. with parentheses in negative numbers: "(12)" for -12.
*/
#ifdef NLS_MAC
#pragma export on
#endif
class T_FORMAT_API NumberFormat : public Format {
public:
/**
* Alignment Field constants used to construct a FieldPosition object.
* Signifies that the position of the integer part or fraction part of
* a formatted number should be returned.
*
* @see FieldPosition
*/
enum EAlignmentFields {
INTEGER_FIELD,
FRACTION_FIELD
};
virtual ~NumberFormat();
/**
* Return true if the given Format objects are semantically equal.
* Objects of different subclasses are considered unequal.
*/
virtual t_bool operator==(const Format& other) const;
/**
* Format an object to produce a string. This method handles
* Formattable objects with numeric types. If the Formattable
* object type is not a numeric type, then it returns a failing
* ErrorCode.
*
* @param obj The object to format.
* @param toAppendTo Where the text is to be appended.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @param status Output param filled with success/failure status.
* @return The value passed in as toAppendTo (this allows chaining,
* as with UnicodeString::append())
*/
virtual UnicodeString& format(const Formattable& obj,
UnicodeString& toAppendTo,
FieldPosition& pos,
ErrorCode& status) const;
/**
* Parse a string to produce an object. This methods handles
* parsing of numeric strings into Formattable objects with numeric
* types.
* <P>
* Before calling, set parse_pos.index to the offset you want to
* start parsing at in the source. After calling, parse_pos.index
* is the end of the text you parsed. If error occurs, index is
* unchanged.
* <P>
* When parsing, leading whitespace is discarded (with successful
* parse), while trailing whitespace is left as is.
* <P>
* See Format::parseObject() for more.
*
* @param source The string to be parsed into an object.
* @param result Formattable to be set to the parse result.
* If parse fails, return contents are undefined.
* @param parse_pos The position to start parsing at. Upon return
* this param is set to the position after the
* last character successfully parsed. If the
* source is not parsed successfully, this param
* will remain unchanged.
* @return A newly created Formattable* object, or NULL
* on failure. The caller owns this and should
* delete it when done.
*/
virtual void parseObject(const UnicodeString& source,
Formattable& result,
ParsePosition& parse_pos) const;
/**
* Format a double or long number. These methods call the NumberFormat
* pure virtual format() methods with the default FieldPosition.
*
* @param number The value to be formatted.
* @param output Output param with the formatted string.
* @return A reference to 'output' param.
*/
UnicodeString& format( double number,
UnicodeString& output) const;
UnicodeString& format( long number,
UnicodeString& output) const;
/**
* Format a double or long number. Concrete subclasses must implement
* these pure virtual methods.
*
* @param number The value to be formatted.
* @param toAppendTo The string to append the formatted string to.
* This is an output parameter.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @return A reference to 'toAppendTo'.
*/
virtual UnicodeString& format(double number,
UnicodeString& toAppendTo,
FieldPosition& pos) const = 0;
virtual UnicodeString& format(long number,
UnicodeString& toAppendTo,
FieldPosition& pos) const = 0;
/**
* Return a long if possible (e.g. within range LONG_MAX,
* LONG_MAX], and with no decimals), otherwise a double. If
* IntegerOnly is set, will stop at a decimal point (or equivalent;
* e.g. for rational numbers "1 2/3", will stop after the 1).
* <P>
* If no object can be parsed, index is unchanged, and NULL is
* returned.
* <P>
* This is a pure virtual which concrete subclasses must implement.
*
* @param text The text to be parsed.
* @param result Formattable to be set to the parse result.
* If parse fails, return contents are undefined.
* @param parsePosition The position to start parsing at on input.
* On output, moved to after the last successfully
* parse character. On parse failure, does not change.
* @return A Formattable object of numeric type. The caller
* owns this an must delete it. NULL on failure.
*/
virtual void parse(const UnicodeString& text,
Formattable& result,
ParsePosition& parsePosition) const = 0;
/**
* Parse a string as a numeric value, and return a Formattable
* numeric object. This method parses integers only if IntegerOnly
* is set.
*
* @param text The text to be parsed.
* @param result Formattable to be set to the parse result.
* If parse fails, return contents are undefined.
* @param status Success or failure output parameter.
* @return A Formattable object of numeric type. The caller
* owns this an must delete it. NULL on failure.
* @see NumberFormat::isParseIntegerOnly
*/
virtual void parse( const UnicodeString& text,
Formattable& result,
ErrorCode& status) const;
/**
* Return true if this format will parse numbers as integers
* only. For example in the English locale, with ParseIntegerOnly
* true, the string "1234." would be parsed as the integer value
* 1234 and parsing would stop at the "." character. Of course,
* the exact format accepted by the parse operation is locale
* dependant and determined by sub-classes of NumberFormat.
*/
t_bool isParseIntegerOnly() const;
/**
* Sets whether or not numbers should be parsed as integers only.
* @see isParseIntegerOnly
*/
virtual void setParseIntegerOnly(t_bool value);
/**
* Returns the default number format for the current default
* locale. The default format is one of the styles provided by
* the other factory methods: getNumberInstance,
* getCurrencyInstance or getPercentInstance. Exactly which one
* is locale dependant.
*/
static NumberFormat* createInstance(ErrorCode&);
/**
* Returns the default number format for the specified locale.
* The default format is one of the styles provided by the other
* factory methods: getNumberInstance, getCurrencyInstance or
* getPercentInstance. Exactly which one is locale dependant.
*/
static NumberFormat* createInstance(const Locale& inLocale,
ErrorCode&);
/**
* Returns a currency format for the current default locale.
*/
static NumberFormat* createCurrencyInstance(ErrorCode&);
/**
* Returns a currency format for the specified locale.
*/
static NumberFormat* createCurrencyInstance(const Locale& inLocale,
ErrorCode&);
/**
* Returns a percentage format for the current default locale.
*/
static NumberFormat* createPercentInstance(ErrorCode&);
/**
* Returns a percentage format for the specified locale.
*/
static NumberFormat* createPercentInstance(const Locale& inLocale,
ErrorCode&);
/**
* Get the set of Locales for which NumberFormats are installed.
*/
static const Locale* getAvailableLocales(t_int32& count);
/**
* Returns true if grouping is used in this format. For example,
* in the English locale, with grouping on, the number 1234567
* might be formatted as "1,234,567". The grouping separator as
* well as the size of each group is locale dependant and is
* determined by sub-classes of NumberFormat.
* @see setGroupingUsed
*/
t_bool isGroupingUsed() const;
/**
* Set whether or not grouping will be used in this format.
* @see getGroupingUsed
*/
virtual void setGroupingUsed(t_bool newValue);
/**
* Returns the maximum number of digits allowed in the integer portion of a
* number.
* @see setMaximumIntegerDigits
*/
int getMaximumIntegerDigits() const;
/**
* Sets the maximum number of digits allowed in the integer portion of a
* number. maximumIntegerDigits must be >= minimumIntegerDigits. If the
* new value for maximumIntegerDigits is less than the current value
* of minimumIntegerDigits, then minimumIntegerDigits will also be set to
* the new value.
*
* @see getMaximumIntegerDigits
*/
virtual void setMaximumIntegerDigits(int newValue);
/**
* Returns the minimum number of digits allowed in the integer portion of a
* number.
* @see setMinimumIntegerDigits
*/
int getMinimumIntegerDigits() const;
/**
* Sets the minimum number of digits allowed in the integer portion of a
* number. minimumIntegerDigits must be &lt;= maximumIntegerDigits. If the
* new value for minimumIntegerDigits exceeds the current value
* of maximumIntegerDigits, then maximumIntegerDigits will also be set to
* the new value.
* @see getMinimumIntegerDigits
*/
virtual void setMinimumIntegerDigits(int newValue);
/**
* Returns the maximum number of digits allowed in the fraction portion of a
* number.
* @see setMaximumFractionDigits
*/
int getMaximumFractionDigits() const;
/**
* Sets the maximum number of digits allowed in the fraction portion of a
* number. maximumFractionDigits must be >= minimumFractionDigits. If the
* new value for maximumFractionDigits is less than the current value
* of minimumFractionDigits, then minimumFractionDigits will also be set to
* the new value.
* @see getMaximumFractionDigits
*/
virtual void setMaximumFractionDigits(int newValue);
/**
* Returns the minimum number of digits allowed in the fraction portion of a
* number.
* @see setMinimumFractionDigits
*/
int getMinimumFractionDigits() const;
/**
* Sets the minimum number of digits allowed in the fraction portion of a
* number. minimumFractionDigits must be &lt;= maximumFractionDigits. If the
* new value for minimumFractionDigits exceeds the current value
* of maximumFractionDigits, then maximumIntegerDigits will also be set to
* the new value
* @see getMinimumFractionDigits
*/
virtual void setMinimumFractionDigits(int newValue);
public:
/**
* Return the class ID for this class. This is useful only for
* comparing to a return value from getDynamicClassID(). For example:
* <pre>
* . Base* polymorphic_pointer = createPolymorphicObject();
* . if (polymorphic_pointer->getDynamicClassID() ==
* . Derived::getStaticClassID()) ...
* </pre>
* @return The class ID for all objects of this class.
*/
static ClassID getStaticClassID() { return (ClassID)&fgClassID; }
/**
* Override Calendar
* Returns a unique class ID POLYMORPHICALLY. Pure virtual override.
* This method is to implement a simple version of RTTI, since not all
* C++ compilers support genuine RTTI. Polymorphic operator==() and
* clone() methods call this method.
* <P>
* @return The class ID for this object. All objects of a
* given class have the same class ID. Objects of
* other classes have different class IDs.
*/
virtual ClassID getDynamicClassID() const { return getStaticClassID(); }
protected:
/**
* Default constructor for subclass use only.
*/
NumberFormat();
/**
* Copy constructor.
*/
NumberFormat(const NumberFormat&);
/**
* Assignment operator.
*/
NumberFormat& operator=(const NumberFormat&);
protected:
static const int MAX_INTEGER_DIGITS;
private:
static char fgClassID;
enum EStyles {
NUMBERSTYLE,
CURRENCYSTYLE,
PERCENTSTYLE
};
static NumberFormat* createInstance(const Locale& desiredLocale, EStyles choice, ErrorCode& success);
static const int NUMBER_PATTERNS_COUNT;
static const UnicodeString kLastResortNumberPatterns[];
t_bool fGroupingUsed;
int fMaxIntegerDigits;
int fMinIntegerDigits;
int fMaxFractionDigits;
int fMinFractionDigits;
t_bool fParseIntegerOnly;
};
#ifdef NLS_MAC
#pragma export off
#endif
// -------------------------------------
inline t_bool
NumberFormat::isParseIntegerOnly() const
{
return fParseIntegerOnly;
}
#endif // _NUMFMT
//eof