#if wxUSE_WCHAR_T
+// the error value returned by wxMBConv methods
+#define wxCONV_FAILED ((size_t)-1)
+
// ----------------------------------------------------------------------------
// wxMBConv (abstract base class for conversions)
// ----------------------------------------------------------------------------
+// When deriving a new class from wxMBConv you must reimplement ToWChar() and
+// FromWChar() methods which are not pure virtual only for historical reasons,
+// don't let the fact that the existing classes implement MB2WC/WC2MB() instead
+// confuse you.
+//
+// And you might need to override GetMBNulLen() as well.
class WXDLLIMPEXP_BASE wxMBConv
{
public:
- // The functions doing actual conversion. On success, the return value is
- // the length (i.e. the number of characters, not bytes, and not counting
- // the trailing L'\0') of the converted string. On failure, (size_t)-1 is
- // returned. In the special case when outputBuf is NULL the return value is
- // the same one but nothing is written to the buffer.
+ // The functions doing actual conversion from/to narrow to/from wide
+ // character strings.
//
- // Note that outLen is the length of the output buffer, not the length of
- // the input (which is always supposed to be terminated by one or more
- // NULs, as appropriate for the encoding)!
- virtual size_t MB2WC(wchar_t *out, const char *in, size_t outLen) const = 0;
- virtual size_t WC2MB(char *out, const wchar_t *in, size_t outLen) const = 0;
+ // On success, the return value is the length (i.e. the number of
+ // characters, not bytes) of the converted string including any trailing
+ // L'\0' or (possibly multiple) '\0'(s). If the conversion fails or if
+ // there is not enough space for everything, including the trailing NUL
+ // character(s), in the output buffer, (size_t)-1 is returned.
+ //
+ // In the special case when dstLen is 0 (outputBuf may be NULL then) the
+ // return value is the length of the needed buffer but nothing happens
+ // otherwise. If srcLen is -1, the entire string, up to and including the
+ // trailing NUL(s), is converted, otherwise exactly srcLen bytes are.
+ //
+ // Typical usage:
+ //
+ // size_t dstLen = conv.ToWChar(NULL, 0, src);
+ // if ( dstLen != wxCONV_FAILED )
+ // ... handle error ...
+ // wchar_t *wbuf = new wchar_t[dstLen];
+ // conv.ToWChar(wbuf, dstLen, src);
+ //
+ virtual size_t ToWChar(wchar_t *dst, size_t dstLen,
+ const char *src, size_t srcLen = -1) const;
+
+ virtual size_t FromWChar(char *dst, size_t dstLen,
+ const wchar_t *src, size_t srcLen = -1) const;
- // MB <-> WC
+
+ // Convenience functions for translating NUL-terminated strings: returns
+ // the buffer containing the converted string or NULL pointer if the
+ // conversion failed.
const wxWCharBuffer cMB2WC(const char *in) const;
const wxCharBuffer cWC2MB(const wchar_t *in) const;
- // Functions converting strings which may contain embedded NULs and don't
- // have to be NUL-terminated.
+ // Convenience functions for converting strings which may contain embedded
+ // NULs and don't have to be NUL-terminated.
//
// inLen is the length of the buffer including trailing NUL if any: if the
// last 4 bytes of the buffer are all NULs, these functions are more
const wxWCharBuffer cWX2WC(const char *psz) const { return cMB2WC(psz); }
#endif // Unicode/ANSI
- // virtual dtor for any base class
- virtual ~wxMBConv();
+ // this function is used in the implementation of cMB2WC() to distinguish
+ // between the following cases:
+ //
+ // a) var width encoding with strings terminated by a single NUL
+ // (usual multibyte encodings): return 1 in this case
+ // b) fixed width encoding with 2 bytes/char and so terminated by
+ // 2 NULs (UTF-16/UCS-2 and variants): return 2 in this case
+ // c) fixed width encoding with 4 bytes/char and so terminated by
+ // 4 NULs (UTF-32/UCS-4 and variants): return 4 in this case
+ //
+ // anything else is not supported currently and -1 should be returned
+ virtual size_t GetMBNulLen() const { return 1; }
-private:
- // this function must return the multibyte representation of L'\0'
+ // return the maximal value currently returned by GetMBNulLen() for any
+ // encoding
+ static size_t GetMaxMBNulLen() { return 4 /* for UTF-32 */; }
+
+
+ // The old conversion functions. The existing classes currently mostly
+ // implement these ones but we're in transition to using To/FromWChar()
+ // instead and any new classes should implement just the new functions.
+ // For now, however, we provide default implementation of To/FromWChar() in
+ // this base class in terms of MB2WC/WC2MB() to avoid having to rewrite all
+ // the conversions at once.
//
- // on error, nulLen should be set to -1
- virtual const char *GetMBNul(size_t *nulLen) const
- {
- *nulLen = 1;
+ // On success, the return value is the length (i.e. the number of
+ // characters, not bytes) not counting the trailing NUL(s) of the converted
+ // string. On failure, (size_t)-1 is returned. In the special case when
+ // outputBuf is NULL the return value is the same one but nothing is
+ // written to the buffer.
+ //
+ // Note that outLen is the length of the output buffer, not the length of
+ // the input (which is always supposed to be terminated by one or more
+ // NULs, as appropriate for the encoding)!
+ virtual size_t MB2WC(wchar_t *out, const char *in, size_t outLen) const;
+ virtual size_t WC2MB(char *out, const wchar_t *in, size_t outLen) const;
- return "";
- }
+
+ // virtual dtor for any base class
+ virtual ~wxMBConv();
};
// ----------------------------------------------------------------------------
return m_conv->WC2MB(out, in, outLen);
}
-private:
- virtual wxCharBuffer GetMBNul(size_t *nulLen) const
+ virtual size_t GetMBNulLen() const
{
- return m_conv->GetMBNul(nulLen);
+ // cast needed to call a private function
+ return m_conv->GetMBNulLen();
}
-
+private:
// the conversion object we forward to
wxMBConv *m_conv;
};
class WXDLLIMPEXP_BASE wxMBConvUTF16Base : public wxMBConv
{
-private:
- virtual const char *GetMBNul(size_t *nulLen) const
- {
- *nulLen = 2;
- return "\0";
- }
+public:
+ virtual size_t GetMBNulLen() const { return 2; }
};
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxMBConvUTF32Base : public wxMBConv
{
-private:
- virtual const char *GetMBNul(size_t *nulLen) const
- {
- *nulLen = 4;
- return "\0\0\0";
- }
+public:
+ virtual size_t GetMBNulLen() const { return 4; }
};
// ----------------------------------------------------------------------------
virtual size_t MB2WC(wchar_t *outputBuf, const char *psz, size_t outputSize) const;
virtual size_t WC2MB(char *outputBuf, const wchar_t *psz, size_t outputSize) const;
+ virtual size_t GetMBNulLen() const;
void Clear() ;
// charset string
void SetName(const wxChar *charset);
- virtual const char *GetMBNul(size_t *nulLen) const;
-
// note that we can't use wxString here because of compilation
// dependencies: we're included from wx/string.h
projects / wxWidgets.git / blobdiff