+ size_t MB2WC(wchar_t *buf, const char *psz, size_t n) const
+ {
+ // note that we have to use MB_ERR_INVALID_CHARS flag as it without it
+ // the behaviour is not compatible with the Unix version (using iconv)
+ // and break the library itself, e.g. wxTextInputStream::NextChar()
+ // wouldn't work if reading an incomplete MB char didn't result in an
+ // error
+ const size_t len = ::MultiByteToWideChar
+ (
+ m_CodePage, // code page
+ MB_ERR_INVALID_CHARS, // flags: fall on error
+ psz, // input string
+ -1, // its length (NUL-terminated)
+ buf, // output string
+ buf ? n : 0 // size of output buffer
+ );
+
+ // note that it returns count of written chars for buf != NULL and size
+ // of the needed buffer for buf == NULL so in either case the length of
+ // the string (which never includes the terminating NUL) is one less
+ return len ? len - 1 : (size_t)-1;
+ }
+
+ size_t WC2MB(char *buf, const wchar_t *pwz, size_t n) const
+ {
+ /*
+ we have a problem here: by default, WideCharToMultiByte() may
+ replace characters unrepresentable in the target code page with bad
+ quality approximations such as turning "1/2" symbol (U+00BD) into
+ "1" for the code pages which don't have it and we, obviously, want
+ to avoid this at any price
+
+ the trouble is that this function does it _silently_, i.e. it won't
+ even tell us whether it did or not... Win98/2000 and higher provide
+ WC_NO_BEST_FIT_CHARS but it doesn't work for the older systems and
+ we have to resort to a round trip, i.e. check that converting back
+ results in the same string -- this is, of course, expensive but
+ otherwise we simply can't be sure to not garble the data.
+ */
+
+ // determine if we can rely on WC_NO_BEST_FIT_CHARS: according to MSDN
+ // it doesn't work with CJK encodings (which we test for rather roughly
+ // here...) nor with UTF-7/8 nor, of course, with Windows versions not
+ // supporting it
+ BOOL usedDef wxDUMMY_INITIALIZE(false),
+ *pUsedDef;
+ int flags;
+ if ( CanUseNoBestFit() && m_CodePage < 50000 )
+ {
+ // it's our lucky day
+ flags = WC_NO_BEST_FIT_CHARS;
+ pUsedDef = &usedDef;
+ }
+ else // old system or unsupported encoding
+ {
+ flags = 0;
+ pUsedDef = NULL;
+ }
+
+ const size_t len = ::WideCharToMultiByte
+ (
+ m_CodePage, // code page
+ flags, // either none or no best fit
+ pwz, // input string
+ -1, // it is (wide) NUL-terminated
+ buf, // output buffer
+ buf ? n : 0, // and its size
+ NULL, // default "replacement" char
+ pUsedDef // [out] was it used?
+ );
+
+ if ( !len )
+ {
+ // function totally failed
+ return (size_t)-1;
+ }
+
+ // if we were really converting, check if we succeeded
+ if ( buf )
+ {
+ if ( flags )
+ {
+ // check if the conversion failed, i.e. if any replacements
+ // were done
+ if ( usedDef )
+ return (size_t)-1;
+ }
+ else // we must resort to double tripping...
+ {
+ wxWCharBuffer wcBuf(n);
+ if ( MB2WC(wcBuf.data(), buf, n) == (size_t)-1 ||
+ wcscmp(wcBuf, pwz) != 0 )
+ {
+ // we didn't obtain the same thing we started from, hence
+ // the conversion was lossy and we consider that it failed
+ return (size_t)-1;
+ }
+ }
+ }
+
+ // see the comment above for the reason of "len - 1"
+ return len - 1;
+ }
+
+ bool IsOk() const { return m_CodePage != -1; }
+
+private:
+ static bool CanUseNoBestFit()
+ {
+ static int s_isWin98Or2k = -1;
+
+ if ( s_isWin98Or2k == -1 )
+ {
+ int verMaj, verMin;
+ switch ( wxGetOsVersion(&verMaj, &verMin) )
+ {
+ case wxWIN95:
+ s_isWin98Or2k = verMaj >= 4 && verMin >= 10;
+ break;
+
+ case wxWINDOWS_NT:
+ s_isWin98Or2k = verMaj >= 5;
+ break;
+
+ default:
+ // unknown, be conseravtive by default
+ s_isWin98Or2k = 0;
+ }
+
+ wxASSERT_MSG( s_isWin98Or2k != -1, _T("should be set above") );
+ }
+
+ return s_isWin98Or2k == 1;
+ }
projects / wxWidgets.git / blobdiff