QChar(3qt)QChar(3qt)NAMEQChar - Lightweight Unicode character
SYNOPSIS
Almost all the functions in this class are reentrant when Qt is built
with thread support. The exception is decomposition(). </p>
#include <qstring.h>
Public Members
QChar ()
QChar ( char c )
QChar ( uchar c )
QChar ( uchar c, uchar r )
QChar ( const QChar & c )
QChar ( ushort rc )
QChar ( short rc )
QChar ( uint rc )
QChar ( int rc )
enum Category { NoCategory, Mark_NonSpacing, Mark_SpacingCombining,
Mark_Enclosing, Number_DecimalDigit, Number_Letter, Number_Other,
Separator_Space, Separator_Line, Separator_Paragraph,
Other_Control, Other_Format, Other_Surrogate, Other_PrivateUse,
Other_NotAssigned, Letter_Uppercase, Letter_Lowercase,
Letter_Titlecase, Letter_Modifier, Letter_Other,
Punctuation_Connector, Punctuation_Dash, Punctuation_Dask =
Punctuation_Dash, Punctuation_Open, Punctuation_Close,
Punctuation_InitialQuote, Punctuation_FinalQuote,
Punctuation_Other, Symbol_Math, Symbol_Currency, Symbol_Modifier,
Symbol_Other }
enum Direction { DirL, DirR, DirEN, DirES, DirET, DirAN, DirCS, DirB,
DirS, DirWS, DirON, DirLRE, DirLRO, DirAL, DirRLE, DirRLO, DirPDF,
DirNSM, DirBN }
enum Decomposition { Single, Canonical, Font, NoBreak, Initial, Medial,
Final, Isolated, Circle, Super, Sub, Vertical, Wide, Narrow, Small,
Square, Compat, Fraction }
enum Joining { OtherJoining, Dual, Right, Center }
enum CombiningClass { Combining_BelowLeftAttached = 200,
Combining_BelowAttached = 202, Combining_BelowRightAttached = 204,
Combining_LeftAttached = 208, Combining_RightAttached = 210,
Combining_AboveLeftAttached = 212, Combining_AboveAttached = 214,
Combining_AboveRightAttached = 216, Combining_BelowLeft = 218,
Combining_Below = 220, Combining_BelowRight = 222, Combining_Left =
224, Combining_Right = 226, Combining_AboveLeft = 228,
Combining_Above = 230, Combining_AboveRight = 232,
Combining_DoubleBelow = 233, Combining_DoubleAbove = 234,
Combining_IotaSubscript = 240 }
int digitValue () const
QChar lower () const
QChar upper () const
Category category () const
Direction direction () const
Joining joining () const
bool mirrored () const
QChar mirroredChar () const
const QString & decomposition () const
Decomposition decompositionTag () const
unsigned char combiningClass () const
char latin1 () const
ushort unicode () const
ushort & unicode ()
operator char () const
bool isNull () const
bool isPrint () const
bool isPunct () const
bool isSpace () const
bool isMark () const
bool isLetter () const
bool isNumber () const
bool isLetterOrNumber () const
bool isDigit () const
bool isSymbol () const
uchar cell () const
uchar row () const
Static Public Members
bool networkOrdered () (obsolete)
RELATED FUNCTION DOCUMENTATION
bool operator== ( QChar c1, QChar c2 )
bool operator== ( char ch, QChar c )
bool operator== ( QChar c, char ch )
int operator!= ( QChar c1, QChar c2 )
int operator!= ( char ch, QChar c )
int operator!= ( QChar c, char ch )
int operator<= ( QChar c1, QChar c2 )
int operator<= ( QChar c, char ch )
int operator<= ( char ch, QChar c )
int operator>= ( QChar c1, QChar c2 )
int operator>= ( QChar c, char ch )
int operator>= ( char ch, QChar c )
int operator< ( QChar c1, QChar c2 )
int operator< ( QChar c, char ch )
int operator< ( char ch, QChar c )
int operator> ( QChar c1, QChar c2 )
int operator> ( QChar c, char ch )
int operator> ( char ch, QChar c )
DESCRIPTION
The QChar class provides a lightweight Unicode character.
Unicode characters are (so far) 16-bit entities without any markup or
structure. This class represents such an entity. It is lightweight, so
it can be used everywhere. Most compilers treat it like a "short int".
(In a few years it may be necessary to make QChar 32-bit when more than
65536 Unicode code points have been defined and come into use.)
QChar provides a full complement of testing/classification functions,
converting to and from other formats, converting from composed to
decomposed Unicode, and trying to compare and case-convert if you ask
it to.
The classification functions include functions like those in ctype.h,
but operating on the full range of Unicode characters. They all return
TRUE if the character is a certain type of character; otherwise they
return FALSE. These classification functions are isNull() (returns TRUE
if the character is U+0000), isPrint() (TRUE if the character is any
sort of printable character, including whitespace), isPunct() (any sort
of punctation), isMark() (Unicode Mark), isLetter (a letter),
isNumber() (any sort of numeric character), isLetterOrNumber(), and
isDigit() (decimal digits). All of these are wrappers around category()
which return the Unicode-defined category of each character.
QChar further provides direction(), which indicates the "natural"
writing direction of this character. The joining() function indicates
how the character joins with its neighbors (needed mostly for Arabic)
and finally mirrored(), which indicates whether the character needs to
be mirrored when it is printed in its" unnatural" writing direction.
Composed Unicode characters (like å) can be converted to
decomposed Unicode ("a" followed by "ring above") by using
decomposition().
In Unicode, comparison is not necessarily possible and case conversion
is very difficult at best. Unicode, covering the" entire" world, also
includes most of the world's case and sorting problems. Qt tries, but
not very hard: operator==() and friends will do comparison based purely
on the numeric Unicode value (code point) of the characters, and
upper() and lower() will do case changes when the character has a well-
defined upper/lower-case equivalent. There is no provision for locale-
dependent case folding rules or comparison; these functions are meant
to be fast so they can be used unambiguously in data structures. (See
QString::localeAwareCompare() though.)
The conversion functions include unicode() (to a scalar), latin1() (to
scalar, but converts all non-Latin-1 characters to 0), row() (gives the
Unicode row), cell() (gives the Unicode cell), digitValue() (gives the
integer value of any of the numerous digit characters), and a host of
constructors.
More information can be found in the document About Unicode.
See also QString, QCharRef, and Text Related Classes.
Member Type Documentation
QChar::Category
This enum maps the Unicode character categories.
The following characters are normative in Unicode:
QChar::Mark_NonSpacing - Unicode class name Mn
QChar::Mark_SpacingCombining - Unicode class name Mc
QChar::Mark_Enclosing - Unicode class name Me
QChar::Number_DecimalDigit - Unicode class name Nd
QChar::Number_Letter - Unicode class name Nl
QChar::Number_Other - Unicode class name No
QChar::Separator_Space - Unicode class name Zs
QChar::Separator_Line - Unicode class name Zl
QChar::Separator_Paragraph - Unicode class name Zp
QChar::Other_Control - Unicode class name Cc
QChar::Other_Format - Unicode class name Cf
QChar::Other_Surrogate - Unicode class name Cs
QChar::Other_PrivateUse - Unicode class name Co
QChar::Other_NotAssigned - Unicode class name Cn
The following categories are informative in Unicode:
QChar::Letter_Uppercase - Unicode class name Lu
QChar::Letter_Lowercase - Unicode class name Ll
QChar::Letter_Titlecase - Unicode class name Lt
QChar::Letter_Modifier - Unicode class name Lm
QChar::Letter_Other - Unicode class name Lo
QChar::Punctuation_Connector - Unicode class name Pc
QChar::Punctuation_Dash - Unicode class name Pd
QChar::Punctuation_Open - Unicode class name Ps
QChar::Punctuation_Close - Unicode class name Pe
QChar::Punctuation_InitialQuote - Unicode class name Pi
QChar::Punctuation_FinalQuote - Unicode class name Pf
QChar::Punctuation_Other - Unicode class name Po
QChar::Symbol_Math - Unicode class name Sm
QChar::Symbol_Currency - Unicode class name Sc
QChar::Symbol_Modifier - Unicode class name Sk
QChar::Symbol_Other - Unicode class name So
There are two categories that are specific to Qt:
QChar::NoCategory - used when Qt is dazed and confused and cannot make
sense of anything.
QChar::Punctuation_Dask - old typo alias for Punctuation_Dash
QChar::CombiningClass
This enum type defines names for some of the Unicode combining classes.
See the Unicode Standard for a description of the values.
QChar::Decomposition
This enum type defines the Unicode decomposition attributes. See the
Unicode Standard for a description of the values.
QChar::Direction
This enum type defines the Unicode direction attributes. See the
Unicode Standard for a description of the values.
In order to conform to C/C++ naming conventions "Dir" is prepended to
the codes used in the Unicode Standard.
QChar::Joining
This enum type defines the Unicode joining attributes. See the Unicode
Standard for a description of the values.
MEMBER FUNCTION DOCUMENTATIONQChar::QChar ()
Constructs a null QChar (one that isNull()).
QChar::QChar ( char c )
Constructs a QChar corresponding to ASCII/Latin-1 character c.
QChar::QChar ( uchar c )
Constructs a QChar corresponding to ASCII/Latin-1 character c.
QChar::QChar ( uchar c, uchar r )
Constructs a QChar for Unicode cell c in row r.
QChar::QChar ( const QChar & c )
Constructs a copy of c. This is a deep copy, if such a lightweight
object can be said to have deep copies.
QChar::QChar ( ushort rc )
Constructs a QChar for the character with Unicode code point rc.
QChar::QChar ( short rc )
Constructs a QChar for the character with Unicode code point rc.
QChar::QChar ( uint rc )
Constructs a QChar for the character with Unicode code point rc.
QChar::QChar ( int rc )
Constructs a QChar for the character with Unicode code point rc.
Category QChar::category () const
Returns the character category.
See also Category.
uchar QChar::cell () const
Returns the cell (least significant byte) of the Unicode character.
unsigned char QChar::combiningClass () const
Returns the combining class for the character as defined in the Unicode
standard. This is mainly useful as a positioning hint for marks
attached to a base character.
The Qt text rendering engine uses this information to correctly
position non spacing marks around a base character.
const QString & QChar::decomposition () const
Warning: This function is not reentrant.</p>
Decomposes a character into its parts. Returns QString::null if no
decomposition exists.
Decomposition QChar::decompositionTag () const
Returns the tag defining the composition of the character. Returns
QChar::Single if no decomposition exists.
int QChar::digitValue () const
Returns the numeric value of the digit, or -1 if the character is not a
digit.
Direction QChar::direction () const
Returns the character's direction.
See also Direction.
bool QChar::isDigit () const
Returns TRUE if the character is a decimal digit (Number_DecimalDigit);
otherwise returns FALSE.
bool QChar::isLetter () const
Returns TRUE if the character is a letter (Letter_* categories);
otherwise returns FALSE.
bool QChar::isLetterOrNumber () const
Returns TRUE if the character is a letter or number (Letter_* or
Number_* categories); otherwise returns FALSE.
bool QChar::isMark () const
Returns TRUE if the character is a mark (Mark_* categories); otherwise
returns FALSE.
bool QChar::isNull () const
Returns TRUE if the character is the Unicode character 0x0000 (ASCII
NUL); otherwise returns FALSE.
bool QChar::isNumber () const
Returns TRUE if the character is a number (of any sort - Number_*
categories); otherwise returns FALSE.
See also isDigit().
bool QChar::isPrint () const
Returns TRUE if the character is a printable character; otherwise
returns FALSE. This is any character not of category Cc or Cn.
Note that this gives no indication of whether the character is
available in a particular font.
bool QChar::isPunct () const
Returns TRUE if the character is a punctuation mark (Punctuation_*
categories); otherwise returns FALSE.
bool QChar::isSpace () const
Returns TRUE if the character is a separator character (Separator_*
categories); otherwise returns FALSE.
bool QChar::isSymbol () const
Returns TRUE if the character is a symbol (Symbol_* categories);
otherwise returns FALSE.
Joining QChar::joining () const
Warning: This function is not supported (it may change to use Unicode
character classes).
Returns information about the joining properties of the character
(needed for example, for Arabic).
char QChar::latin1 () const
Returns the Latin-1 value of this character, or 0 if it cannot be
represented in Latin-1.
QChar QChar::lower () const
Returns the lowercase equivalent if the character is uppercase;
otherwise returns the character itself.
bool QChar::mirrored () const
Returns TRUE if the character is a mirrored character (one that should
be reversed if the text direction is reversed); otherwise returns
FALSE.
QChar QChar::mirroredChar () const
Returns the mirrored character if this character is a mirrored
character, otherwise returns the character itself.
bool QChar::networkOrdered () [static]
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
Returns TRUE if this character is in network byte order (MSB first);
otherwise returns FALSE. This is platform dependent.
QChar::operator char () const
Returns the Latin-1 character equivalent to the QChar, or 0. This is
mainly useful for non-internationalized software.
See also unicode().
uchar QChar::row () const
Returns the row (most significant byte) of the Unicode character.
ushort QChar::unicode () const
Returns the numeric Unicode value equal to the QChar. Normally, you
should use QChar objects as they are equivalent, but for some low-level
tasks (e.g. indexing into an array of Unicode information), this
function is useful.
ushort & QChar::unicode ()
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns a reference to the numeric Unicode value equal to the QChar.
QChar QChar::upper () const
Returns the uppercase equivalent if the character is lowercase;
otherwise returns the character itself.
RELATED FUNCTION DOCUMENTATIONint operator!= ( QChar c1, QChar c2 )
Returns TRUE if c1 and c2 are not the same Unicode character; otherwise
returns FALSE.
int operator!= ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if c is not the ASCII/Latin-1 character ch; otherwise
returns FALSE.
int operator!= ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if c is not the ASCII/Latin-1 character ch; otherwise
returns FALSE.
int operator< ( QChar c1, QChar c2 )
Returns TRUE if the numeric Unicode value of c1 is less than that of
c2; otherwise returns FALSE.
int operator< ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of c is less than that of the
ASCII/Latin-1 character ch; otherwise returns FALSE.
int operator< ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of the ASCII/Latin-1
character ch is less than that of c; otherwise returns FALSE.
int operator<= ( QChar c1, QChar c2 )
Returns TRUE if the numeric Unicode value of c1 is less than that of
c2, or they are the same Unicode character; otherwise returns FALSE.
int operator<= ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of c is less than or equal to
that of the ASCII/Latin-1 character ch; otherwise returns FALSE.
int operator<= ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of the ASCII/Latin-1
character ch is less than or equal to that of c; otherwise returns
FALSE.
bool operator== ( QChar c1, QChar c2 )
Returns TRUE if c1 and c2 are the same Unicode character; otherwise
returns FALSE.
bool operator== ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if c is the ASCII/Latin-1 character ch; otherwise returns
FALSE.
bool operator== ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if c is the ASCII/Latin-1 character ch; otherwise returns
FALSE.
int operator> ( QChar c1, QChar c2 )
Returns TRUE if the numeric Unicode value of c1 is greater than that of
c2; otherwise returns FALSE.
int operator> ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of c is greater than that of
the ASCII/Latin-1 character ch; otherwise returns FALSE.
int operator> ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of the ASCII/Latin-1
character ch is greater than that of c; otherwise returns FALSE.
int operator>= ( QChar c1, QChar c2 )
Returns TRUE if the numeric Unicode value of c1 is greater than that of
c2, or they are the same Unicode character; otherwise returns FALSE.
int operator>= ( QChar c, char ch )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of c is greater than or equal
to that of the ASCII/Latin-1 character ch; otherwise returns FALSE.
int operator>= ( char ch, QChar c )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns TRUE if the numeric Unicode value of the ASCII/Latin-1
character ch is greater than or equal to that of c; otherwise returns
FALSE.
SEE ALSO
http://doc.trolltech.com/qchar.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
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If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qchar.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QChar(3qt)