wxWidgets/interface/wx/strconv.h
Francesco Montorsi 4701dc0983 revised st*.h headers
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56148 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2008-10-07 16:57:34 +00:00

477 lines
17 KiB
Objective-C

/////////////////////////////////////////////////////////////////////////////
// Name: strconv.h
// Purpose: interface of wxMBConvUTF7
// Author: wxWidgets team
// RCS-ID: $Id$
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
/**
@class wxMBConv
This class is the base class of a hierarchy of classes capable of
converting text strings between multibyte (SBCS or DBCS) encodings and
Unicode.
This is an abstract base class which defines the operations implemented by
all different conversion classes. The derived classes don't add any new
operations of their own (except, possibly, some non-default constructors)
and so you should simply use this class ToWChar() and FromWChar() (or
cMB2WC() and cWC2MB()) methods with the objects of the derived class.
In the documentation for this and related classes please notice that
length of the string refers to the number of characters in the string
not counting the terminating @c NUL, if any. While the size of the string
is the total number of bytes in the string, including any trailing @c NUL.
Thus, length of wide character string @c L"foo" is 3 while its size can
be either 8 or 16 depending on whether @c wchar_t is 2 bytes (as
under Windows) or 4 (Unix).
@library{wxbase}
@category{conv}
@see wxCSConv, wxEncodingConverter, @ref overview_mbconv
*/
class wxMBConv
{
public:
/**
Trivial default constructor.
*/
wxMBConv();
/**
This pure virtual function is overridden in each of the derived classes
to return a new copy of the object it is called on.
It is used for copying the conversion objects while preserving their
dynamic type.
*/
virtual wxMBConv* Clone() const = 0;
/**
This function returns 1 for most of the multibyte encodings in which the
string is terminated by a single @c NUL, 2 for UTF-16 and 4 for UTF-32 for
which the string is terminated with 2 and 4 @c NUL characters respectively.
The other cases are not currently supported and @c wxCONV_FAILED
(defined as -1) is returned for them.
*/
virtual size_t GetMBNulLen() const;
/**
Returns the maximal value which can be returned by GetMBNulLen() for
any conversion object.
Currently this value is 4.
This method can be used to allocate the buffer with enough space for the
trailing @c NUL characters for any encoding.
*/
const size_t GetMaxMBNulLen();
/**
Convert multibyte string to a wide character one.
This is the most general function for converting a multibyte string to
a wide string, cMB2WC() may be often more convenient, however this
function is the most efficient one as it allows to avoid any
unnecessary copying.
The main case is when @a dst is not @NULL and @a srcLen is not
@c wxNO_LEN (which is defined as @c (size_t)-1): then the function
converts exactly @a srcLen bytes starting at @a src into wide string
which it output to @e dst. If the length of the resulting wide
string is greater than @e dstLen, an error is returned. Note that if
@a srcLen bytes don't include @c NUL characters, the resulting wide
string is not @c NUL-terminated neither.
If @a srcLen is @c wxNO_LEN, the function supposes that the string is
properly (i.e. as necessary for the encoding handled by this
conversion) @c NUL-terminated and converts the entire string, including
any trailing @c NUL bytes. In this case the wide string is also @c
NUL-terminated.
Finally, if @a dst is @NULL, the function returns the length of the
needed buffer.
Example of use of this function:
@code
size_t dstLen = conv.ToWChar(NULL, 0, src);
if ( dstLen == wxCONV_FAILED )
... handle error ...
wchar_t *dst = new wchar_t[dstLen];
if ( conv.ToWChar(dst, dstLen, src) == wxCONV_FAILED )
... handle error ...
@endcode
Notice that when passing the explicit source length the output will
@e not be @c NUL terminated if you pass @c strlen(str) as parameter.
Either leave @a srcLen as default @c wxNO_LEN or add one to @c strlen
result if you want the output to be @c NUL terminated.
@param dst
Pointer to output buffer of the size of at least @a dstLen or @NULL.
@param dstLen
Maximal number of characters to be written to the output buffer if
@a dst is non-@NULL, unused otherwise.
@param src
Point to the source string, must not be @NULL.
@param srcLen
The number of characters of the source string to convert or
@c wxNO_LEN (default parameter) to convert everything up to and
including the terminating @c NUL character(s).
@return
The number of character written (or which would have been written
if it were non-@NULL) to @a dst or @c wxCONV_FAILED on error.
*/
virtual size_t ToWChar(wchar_t* dst, size_t dstLen,
const char* src,
size_t srcLen = wxNO_LEN) const;
/**
Converts wide character string to multibyte.
This function has the same semantics as ToWChar() except that it
converts a wide string to multibyte one. As with ToWChar(), it may be
more convenient to use cWC2MB() when working with @c NUL terminated
strings.
@param dst
Pointer to output buffer of the size of at least @a dstLen or @NULL.
@param dstLen
Maximal number of characters to be written to the output buffer if
@a dst is non-@NULL, unused otherwise.
@param src
Point to the source string, must not be @NULL.
@param srcLen
The number of characters of the source string to convert or
@c wxNO_LEN (default parameter) to convert everything up to and
including the terminating @c NUL character.
@return
The number of character written (or which would have been written
if it were non-@NULL) to @a dst or @c wxCONV_FAILED on error.
*/
virtual size_t FromWChar(char* dst, size_t dstLen,
const wchar_t* src,
size_t srcLen = wxNO_LEN) const;
/**
Converts from multibyte encoding to Unicode by calling ToWChar() and
allocating a temporary wxWCharBuffer to hold the result.
This function is a convenient wrapper around ToWChar() as it takes care
of allocating the buffer of the necessary size itself. Its parameters
have the same meaning as for ToWChar(), in particular @a inLen can be
specified explicitly in which case exactly that many characters are
converted and @a outLen receives (if non-@NULL) exactly the
corresponding number of wide characters, whether the last one of them
is @c NUL or not. However if @c inLen is @c wxNO_LEN, then @c outLen
doesn't count the trailing @c NUL even if it is always present in this
case.
Finally notice that if the conversion fails, the returned buffer is
invalid and @a outLen is set to 0 (and not @c wxCONV_FAILED for
compatibility concerns).
*/
const wxWCharBuffer cMB2WC(const char* in,
size_t inLen = wxNO_LEN,
size_t *outLen = NULL) const;
//@{
/**
Converts from multibyte encoding to the current wxChar type (which
depends on whether wxUSE_UNICODE is set to 1).
If wxChar is char, it returns the parameter unaltered. If wxChar is
wchar_t, it returns the result in a wxWCharBuffer. The macro wxMB2WXbuf
is defined as the correct return type (without const).
*/
const char* cMB2WX(const char* psz) const;
const wxWCharBuffer cMB2WX(const char* psz) const;
//@}
/**
Converts from Unicode to multibyte encoding by calling FromWChar() and
allocating a temporary wxCharBuffer to hold the result.
This function is a convenient wrapper around FromWChar() as it takes
care of allocating the buffer of necessary size itself.
Its parameters have the same meaning as the corresponding parameters of
FromWChar(), please see the description of cMB2WC() for more details.
*/
const wxCharBuffer cWC2MB(const wchar_t* in,
size_t inLen = wxNO_LEN,
size_t *outLen = NULL) const;
//@{
/**
Converts from Unicode to the current wxChar type.
If wxChar is wchar_t, it returns the parameter unaltered. If wxChar is
char, it returns the result in a wxCharBuffer. The macro wxWC2WXbuf is
defined as the correct return type (without const).
*/
const wchar_t* cWC2WX(const wchar_t* psz) const;
const wxCharBuffer cWC2WX(const wchar_t* psz) const;
//@}
//@{
/**
Converts from the current wxChar type to multibyte encoding.
If wxChar is char, it returns the parameter unaltered. If wxChar is
wchar_t, it returns the result in a wxCharBuffer. The macro wxWX2MBbuf
is defined as the correct return type (without const).
*/
const char* cWX2MB(const wxChar* psz) const;
const wxCharBuffer cWX2MB(const wxChar* psz) const;
//@}
//@{
/**
Converts from the current wxChar type to Unicode.
If wxChar is wchar_t, it returns the parameter unaltered. If wxChar is
char, it returns the result in a wxWCharBuffer. The macro wxWX2WCbuf is
defined as the correct return type (without const).
*/
const wchar_t* cWX2WC(const wxChar* psz) const;
const wxWCharBuffer cWX2WC(const wxChar* psz) const;
//@}
/**
@deprecated This function is deprecated, please use ToWChar() instead.
Converts from a string @a in in multibyte encoding to Unicode putting up to
@a outLen characters into the buffer @e out.
If @a out is @NULL, only the length of the string which would result
from the conversion is calculated and returned. Note that this is the
length and not size, i.e. the returned value does not include the
trailing @c NUL. But when the function is called with a non-@NULL @a
out buffer, the @a outLen parameter should be one more to allow to
properly @c NUL-terminate the string.
@param out
The output buffer, may be @NULL if the caller is only
interested in the length of the resulting string
@param in
The NUL-terminated input string, cannot be @NULL
@param outLen
The length of the output buffer but including
NUL, ignored if out is @NULL
@return The length of the converted string excluding the trailing NUL.
*/
virtual size_t MB2WC(wchar_t* out, const char* in, size_t outLen) const;
/**
@deprecated This function is deprecated, please use FromWChar() instead.
Converts from Unicode to multibyte encoding.
The semantics of this function (including the return value meaning) is
the same as for wxMBConv::MB2WC. Notice that when the function is
called with a non-@NULL buffer, the @a n parameter should be the size
of the buffer and so it should take into account the trailing @c NUL,
which might take two or four bytes for some encodings (UTF-16 and
UTF-32) and not one.
*/
virtual size_t WC2MB(char* buf, const wchar_t* psz, size_t n) const;
};
/**
@class wxMBConvUTF7
This class converts between the UTF-7 encoding and Unicode.
It has one predefined instance, @b wxConvUTF7.
Notice that, unlike all the other conversion objects, this converter is
stateful, i.e. it remembers its state from the last call to its ToWChar()
or FromWChar() and assumes it is called on the continuation of the same
string when the same method is called again. This assumption is only made
if an explicit length is specified as parameter to these functions as if an
entire @c NUL terminated string is processed the state doesn't need to be
remembered.
This also means that, unlike the other predefined conversion objects,
@b wxConvUTF7 is @em not thread-safe.
@library{wxbase}
@category{conv}
@see wxMBConvUTF8, @ref overview_mbconv
*/
class wxMBConvUTF7 : public wxMBConv
{
};
/**
@class wxMBConvUTF8
This class converts between the UTF-8 encoding and Unicode.
It has one predefined instance, @b wxConvUTF8.
@library{wxbase}
@category{conv}
@see wxMBConvUTF7, @ref overview_mbconv
*/
class wxMBConvUTF8 : public wxMBConv
{
};
/**
@class wxMBConvUTF16
This class is used to convert between multibyte encodings and UTF-16 Unicode
encoding (also known as UCS-2).
Unlike UTF-8 encoding, UTF-16 uses words and not bytes and hence depends
on the byte ordering: big or little endian. Hence this class is provided in
two versions: wxMBConvUTF16LE and wxMBConvUTF16BE and wxMBConvUTF16 itself
is just a typedef for one of them (native for the given platform, e.g. LE
under Windows and BE under Mac).
@library{wxbase}
@category{conv}
@see wxMBConvUTF8, wxMBConvUTF32, @ref overview_mbconv
*/
class wxMBConvUTF16 : public wxMBConv
{
};
/**
@class wxMBConvUTF32
This class is used to convert between multibyte encodings and UTF-32
Unicode encoding (also known as UCS-4).
Unlike UTF-8 encoding, UTF-32 uses (double) words and not bytes and hence
depends on the byte ordering: big or little endian. Hence this class is
provided in two versions: wxMBConvUTF32LE and wxMBConvUTF32BE and
wxMBConvUTF32 itself is just a typedef for one of them (native for the
given platform, e.g. LE under Windows and BE under Mac).
@library{wxbase}
@category{conv}
@see wxMBConvUTF8, wxMBConvUTF16, @ref overview_mbconv
*/
class wxMBConvUTF32 : public wxMBConv
{
};
/**
@class wxCSConv
This class converts between any character set supported by the system and
Unicode.
Please notice that this class uses system-provided conversion functions,
e.g. @c MultiByteToWideChar() and @c WideCharToMultiByte() under MSW and @c
iconv(3) under Unix systems and as such may support different encodings and
different encoding names on different platforms (although all relatively
common encodings are supported should be supported everywhere).
It has one predefined instance, @b wxConvLocal, for the default user
character set.
@library{wxbase}
@category{conv}
@see wxMBConv, wxEncodingConverter, @ref overview_mbconv
*/
class wxCSConv : public wxMBConv
{
public:
/**
Constructor.
You can specify the name of the character set you want to convert
from/to. If the character set name is not recognized, ISO 8859-1 is
used as fall back, use IsOk() to test for this.
@param charset The name of the encoding, shouldn't be empty.
*/
wxCSConv(const wxString& charset);
/**
Constructor.
You can specify an encoding constant for the character set you want to
convert from/to. Use IsOk() after construction to check whether the
encoding is supported by the current system.
@param encoding Any valid (i.e. not wxFONTENCODING_MAX) font encoding.
*/
wxCSConv(wxFontEncoding encoding);
/**
Returns @true if the charset (or the encoding) given at constructor is
really available to use.
Returns @false if ISO 8859-1 will be used instead.
Note this does not mean that a given string will be correctly
converted. A malformed string may still make conversion functions
return @c wxCONV_FAILED.
@since 2.8.2
*/
bool IsOk() const;
};
/**
@class wxMBConvFile
This class used to define the class instance @b wxConvFileName, but
nowadays @b wxConvFileName is either of type wxConvLibc (on most platforms)
or wxConvUTF8 (on MacOS X).
@b wxConvFileName converts filenames between filesystem multibyte encoding
and Unicode. @b wxConvFileName can also be set to a something else at
run-time which is used e.g. by wxGTK to use a class which checks the
environment variable @b G_FILESYSTEM_ENCODING indicating that filenames
should not be interpreted as UTF8 and also for converting invalid UTF8
characters (e.g. if there is a filename in iso8859_1) to strings with octal
values.
Since some platforms (such as Win32) use Unicode in the filenames,
and others (such as Unix) use multibyte encodings, this class should only
be used directly if wxMBFILES is defined to 1. A convenience macro,
@c wxFNCONV, is defined to @c wxConvFileName->cWX2MB in this case. You
could use it like this:
@code
wxChar *name = wxT("rawfile.doc");
FILE *fil = fopen(wxFNCONV(name), "r");
@endcode
(although it would be better to just use wxFopen(name, "r") in this
particular case, you only need to use this class for functions taking file
names not wrapped by wxWidgets.)
@library{wxbase}
@category{conv}
@see @ref overview_mbconv
*/
class wxMBConvFile : public wxMBConv
{
public:
};