src/common/strconv.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        strconv.cpp
   3 // Purpose:     Unicode conversion classes
   4 // Author:      Ove Kaaven, Robert Roebling, Vadim Zeitlin
   5 // Modified by:
   6 // Created:     29/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1999 Ove Kaaven, Robert Roebling, Vadim Zeitlin
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21   #pragma implementation "strconv.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28   #pragma hdrstop
  29 #endif
  30
  31 #ifdef __WXMSW__
  32   #include "wx/msw/private.h"
  33 #endif
  34
  35 #include <errno.h>
  36 #include <ctype.h>
  37 #include <string.h>
  38 #include <stdlib.h>
  39
  40 #ifdef __SALFORDC__
  41   #include <clib.h>
  42 #endif
  43
  44 #ifdef HAVE_ICONV_H
  45   #include <iconv.h>
  46 #endif
  47 #ifdef HAVE_LANGINFO_H
  48   #include <langinfo.h>
  49 #endif
  50
  51 #ifdef __WXMSW__
  52   #include <windows.h>
  53 #endif
  54
  55 #include "wx/debug.h"
  56 #include "wx/strconv.h"
  57 #include "wx/intl.h"
  58 #include "wx/log.h"
  59
  60 #if defined(WORDS_BIGENDIAN) || defined(__STDC_ISO_10646__)
  61 #define BSWAP_UCS4(str, len)
  62 #define BSWAP_UCS2(str, len)
  63 #else
  64 #define BSWAP_UCS4(str, len) { unsigned _c; for (_c=0; _c<len; _c++) str[_c]=wxUINT32_SWAP_ALWAYS(str[_c]); }
  65 #define BSWAP_UCS2(str, len) { unsigned _c; for (_c=0; _c<len; _c++) str[_c]=wxUINT16_SWAP_ALWAYS(str[_c]); }
  66 #define WC_NEED_BSWAP
  67 #endif
  68 #define BSWAP_UTF32(str, len) BSWAP_UCS4(str, len)
  69 #define BSWAP_UTF16(str, len) BSWAP_UCS2(str, len)
  70
  71 #if SIZEOF_WCHAR_T == 4
  72 #define WC_NAME "UCS4"
  73 #define WC_BSWAP BSWAP_UCS4
  74 #elif SIZEOF_WCHAR_T == 2
  75 #define WC_NAME "UTF16"
  76 #define WC_BSWAP BSWAP_UTF16
  77 #define WC_UTF16
  78 #endif
  79
  80 // ----------------------------------------------------------------------------
  81 // globals
  82 // ----------------------------------------------------------------------------
  83
  84 WXDLLEXPORT_DATA(wxMBConv *) wxConvCurrent = &wxConvLibc;
  85
  86 // ============================================================================
  87 // implementation
  88 // ============================================================================
  89
  90 #if wxUSE_WCHAR_T
  91
  92 #ifdef WC_UTF16
  93
  94 static size_t encode_utf16(wxUint32 input,wxUint16*output)
  95 {
  96   if (input<=0xffff) {
  97     if (output) *output++ = input;
  98     return 1;
  99   } else
 100   if (input>=0x110000) {
 101     return (size_t)-1;
 102   } else {
 103     if (output) {
 104       *output++ = (input >> 10)+0xd7c0;
 105       *output++ = (input&0x3ff)+0xdc00;
 106     }
 107     return 2;
 108   }
 109 }
 110
 111 static size_t decode_utf16(wxUint16*input,wxUint32&output)
 112 {
 113   if ((*input<0xd800) || (*input>0xdfff)) {
 114     output = *input;
 115     return 1;
 116   } else
 117   if ((input[1]<0xdc00) || (input[1]>=0xdfff)) {
 118     output = *input;
 119     return (size_t)-1;
 120   } else {
 121     output = ((input[0] - 0xd7c0) << 10) + (input[1] - 0xdc00);
 122     return 2;
 123   }
 124 }
 125
 126 #endif // WC_UTF16
 127
 128 // ----------------------------------------------------------------------------
 129 // wxMBConv
 130 // ----------------------------------------------------------------------------
 131
 132 WXDLLEXPORT_DATA(wxMBConv) wxConvLibc;
 133
 134 size_t wxMBConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
 135 {
 136     return wxMB2WC(buf, psz, n);
 137 }
 138
 139 size_t wxMBConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
 140 {
 141     return wxWC2MB(buf, psz, n);
 142 }
 143
 144 const wxWCharBuffer wxMBConv::cMB2WC(const char *psz) const
 145 {
 146     if (psz)
 147     {
 148         size_t nLen = MB2WC((wchar_t *) NULL, psz, 0);
 149         if (nLen == (size_t)-1)
 150             return wxWCharBuffer((wchar_t *) NULL);
 151         wxWCharBuffer buf(nLen);
 152         MB2WC((wchar_t *)(const wchar_t *) buf, psz, nLen);
 153         return buf;
 154     }
 155     else
 156         return wxWCharBuffer((wchar_t *) NULL);
 157 }
 158
 159 const wxCharBuffer wxMBConv::cWC2MB(const wchar_t *psz) const
 160 {
 161     if (psz)
 162     {
 163         size_t nLen = WC2MB((char *) NULL, psz, 0);
 164         if (nLen == (size_t)-1)
 165             return wxCharBuffer((char *) NULL);
 166         wxCharBuffer buf(nLen);
 167         WC2MB((char *)(const char *) buf, psz, nLen);
 168         return buf;
 169     }
 170     else
 171         return wxCharBuffer((char *) NULL);
 172 }
 173
 174 // ----------------------------------------------------------------------------
 175 // standard file conversion
 176 // ----------------------------------------------------------------------------
 177
 178 WXDLLEXPORT_DATA(wxMBConvFile) wxConvFile;
 179
 180 // just use the libc conversion for now
 181 size_t wxMBConvFile::MB2WC(wchar_t *buf, const char *psz, size_t n) const
 182 {
 183     return wxMB2WC(buf, psz, n);
 184 }
 185
 186 size_t wxMBConvFile::WC2MB(char *buf, const wchar_t *psz, size_t n) const
 187 {
 188     return wxWC2MB(buf, psz, n);
 189 }
 190
 191 // ----------------------------------------------------------------------------
 192 // standard gdk conversion
 193 // ----------------------------------------------------------------------------
 194
 195 #ifdef __WXGTK12__
 196
 197 WXDLLEXPORT_DATA(wxMBConvGdk) wxConvGdk;
 198
 199 #include <gdk/gdk.h>
 200
 201 size_t wxMBConvGdk::MB2WC(wchar_t *buf, const char *psz, size_t n) const
 202 {
 203   if (buf) {
 204     return gdk_mbstowcs((GdkWChar *)buf, psz, n);
 205   } else {
 206     GdkWChar *nbuf = new GdkWChar[n=strlen(psz)];
 207     size_t len = gdk_mbstowcs(nbuf, psz, n);
 208     delete [] nbuf;
 209     return len;
 210   }
 211 }
 212
 213 size_t wxMBConvGdk::WC2MB(char *buf, const wchar_t *psz, size_t n) const
 214 {
 215   char *mbstr = gdk_wcstombs((GdkWChar *)psz);
 216   size_t len = mbstr ? strlen(mbstr) : 0;
 217   if (buf) {
 218     if (len > n) len = n;
 219     memcpy(buf, psz, len);
 220     if (len < n) buf[len] = 0;
 221   }
 222   return len;
 223 }
 224
 225 #endif // GTK > 1.0
 226
 227 // ----------------------------------------------------------------------------
 228 // UTF-7
 229 // ----------------------------------------------------------------------------
 230
 231 WXDLLEXPORT_DATA(wxMBConvUTF7) wxConvUTF7;
 232
 233 #if 0
 234 static char utf7_setD[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 235                         "abcdefghijklmnopqrstuvwxyz"
 236                         "0123456789'(),-./:?";
 237 static char utf7_setO[]="!\"#$%&*;<=>@[]^_`{|}";
 238 static char utf7_setB[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 239                         "abcdefghijklmnopqrstuvwxyz"
 240                         "0123456789+/";
 241 #endif
 242
 243 // TODO: write actual implementations of UTF-7 here
 244 size_t wxMBConvUTF7::MB2WC(wchar_t * WXUNUSED(buf),
 245                            const char * WXUNUSED(psz),
 246                            size_t WXUNUSED(n)) const
 247 {
 248   return 0;
 249 }
 250
 251 size_t wxMBConvUTF7::WC2MB(char * WXUNUSED(buf),
 252                            const wchar_t * WXUNUSED(psz),
 253                            size_t WXUNUSED(n)) const
 254 {
 255   return 0;
 256 }
 257
 258 // ----------------------------------------------------------------------------
 259 // UTF-8
 260 // ----------------------------------------------------------------------------
 261
 262 WXDLLEXPORT_DATA(wxMBConvUTF8) wxConvUTF8;
 263
 264 static wxUint32 utf8_max[]={0x7f,0x7ff,0xffff,0x1fffff,0x3ffffff,0x7fffffff,0xffffffff};
 265
 266 size_t wxMBConvUTF8::MB2WC(wchar_t *buf, const char *psz, size_t n) const
 267 {
 268   size_t len = 0;
 269
 270   while (*psz && ((!buf) || (len<n))) {
 271     unsigned char cc=*psz++, fc=cc;
 272     unsigned cnt;
 273     for (cnt=0; fc&0x80; cnt++) fc<<=1;
 274     if (!cnt) {
 275       // plain ASCII char
 276       if (buf) *buf++=cc;
 277       len++;
 278     } else {
 279       cnt--;
 280       if (!cnt) {
 281         // invalid UTF-8 sequence
 282         return (size_t)-1;
 283       } else {
 284         unsigned ocnt=cnt-1;
 285         wxUint32 res=cc&(0x3f>>cnt);
 286         while (cnt--) {
 287           cc = *psz++;
 288           if ((cc&0xC0)!=0x80) {
 289             // invalid UTF-8 sequence
 290             return (size_t)-1;
 291           }
 292           res=(res<<6)|(cc&0x3f);
 293         }
 294         if (res<=utf8_max[ocnt]) {
 295           // illegal UTF-8 encoding
 296           return (size_t)-1;
 297         }
 298 #ifdef WC_UTF16
 299         size_t pa = encode_utf16(res, buf);
 300         if (pa == (size_t)-1)
 301           return (size_t)-1;
 302         if (buf) buf+=pa;
 303         len+=pa;
 304 #else
 305         if (buf) *buf++=res;
 306         len++;
 307 #endif
 308       }
 309     }
 310   }
 311   if (buf && (len<n)) *buf = 0;
 312   return len;
 313 }
 314
 315 size_t wxMBConvUTF8::WC2MB(char *buf, const wchar_t *psz, size_t n) const
 316 {
 317   size_t len = 0;
 318
 319   while (*psz && ((!buf) || (len<n))) {
 320     wxUint32 cc;
 321 #ifdef WC_UTF16
 322     size_t pa = decode_utf16(psz,cc);
 323     psz += (pa == (size_t)-1) ? 1 : pa;
 324 #else
 325     cc=(*psz++)&0x7fffffff;
 326 #endif
 327     unsigned cnt;
 328     for (cnt=0; cc>utf8_max[cnt]; cnt++);
 329     if (!cnt) {
 330       // plain ASCII char
 331       if (buf) *buf++=cc;
 332       len++;
 333     } else {
 334       len+=cnt+1;
 335       if (buf) {
 336         *buf++=(-128>>cnt)|((cc>>(cnt*6))&(0x3f>>cnt));
 337         while (cnt--)
 338           *buf++=0x80|((cc>>(cnt*6))&0x3f);
 339       }
 340     }
 341   }
 342   if (buf && (len<n)) *buf = 0;
 343   return len;
 344 }
 345
 346 // ----------------------------------------------------------------------------
 347 // specified character set
 348 // ----------------------------------------------------------------------------
 349
 350 WXDLLEXPORT_DATA(wxCSConv) wxConvLocal((const wxChar *)NULL);
 351
 352 #include "wx/encconv.h"
 353 #include "wx/fontmap.h"
 354
 355 // TODO: add some tables here
 356 // - perhaps common encodings to common codepages (for Win32)
 357 // - perhaps common encodings to objects ("UTF8" -> wxConvUTF8)
 358 // - move wxEncodingConverter meat in here
 359
 360 #ifdef __WIN32__
 361 #include "wx/msw/registry.h"
 362 // this should work if M$ Internet Exploiter is installed
 363 static long CharsetToCodepage(const wxChar *name)
 364 {
 365     if (!name)
 366         return GetACP();
 367
 368     long CP=-1;
 369
 370     wxString cn(name);
 371     do {
 372         wxString path( wxT("MIME\\Database\\Charset\\") );
 373         path += cn;
 374         wxRegKey key( wxRegKey::HKCR, path );
 375
 376         /* two cases: either there's an AliasForCharset string,
 377          * or there are Codepage and InternetEncoding dwords.
 378          * The InternetEncoding gives us the actual encoding,
 379          * the Codepage just says which Windows character set to
 380          * use when displaying the data.
 381          */
 382         if (key.QueryValue( wxT("InternetEncoding"), &CP )) break;
 383
 384         // no encoding, see if it's an alias
 385         if (!key.QueryValue( wxT("AliasForCharset"), cn )) break;
 386     } while (1);
 387
 388     return CP;
 389 }
 390 #endif
 391
 392 class wxCharacterSet
 393 {
 394 public:
 395     wxCharacterSet(const wxChar*name)
 396         : cname(name) {}
 397     virtual ~wxCharacterSet()
 398         {}
 399     virtual size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
 400         { return (size_t)-1; }
 401     virtual size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
 402         { return (size_t)-1; }
 403     virtual bool usable()
 404         { return FALSE; }
 405 public:
 406     const wxChar*cname;
 407 };
 408
 409 class ID_CharSet : public wxCharacterSet
 410 {
 411 public:
 412     ID_CharSet(const wxChar*name,wxMBConv*cnv)
 413         : wxCharacterSet(name), work(cnv) {}
 414
 415     size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
 416         { return work ? work->MB2WC(buf,psz,n) : (size_t)-1; }
 417
 418     size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
 419         { return work ? work->WC2MB(buf,psz,n) : (size_t)-1; }
 420
 421     bool usable()
 422         { return work!=NULL; }
 423 public:
 424     wxMBConv*work;
 425 };
 426
 427
 428 #ifdef HAVE_ICONV_H
 429
 430 // VS: glibc 2.1.3 is broken in that iconv() conversion to/from UCS4 fails with E2BIG
 431 //     if output buffer is _exactly_ as big as needed. Such case is (unless there's
 432 //     yet another bug in glibc) the only case when iconv() returns with (size_t)-1
 433 //     (which means error) and says there are 0 bytes left in the input buffer --
 434 //     when _real_ error occurs, bytes-left-in-input buffer is non-zero. Hence,
 435 //     this alternative test for iconv() failure.
 436 //     [This bug does not appear in glibc 2.2.]
 437 #if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ <= 1
 438 #define ICONV_FAILED(cres, bufLeft) ((cres == (size_t)-1) && \
 439                                      (errno != E2BIG || bufLeft != 0))
 440 #else
 441 #define ICONV_FAILED(cres, bufLeft)  (cres == (size_t)-1)
 442 #endif
 443
 444 class IC_CharSet : public wxCharacterSet
 445 {
 446 public:
 447     IC_CharSet(const wxChar*name)
 448         : wxCharacterSet(name)
 449     {
 450         m2w = iconv_open(WC_NAME, wxConvLibc.cWX2MB(cname));
 451         w2m = iconv_open(wxConvLibc.cWX2MB(cname), WC_NAME);
 452     }
 453
 454     ~IC_CharSet()
 455     {
 456         if ( m2w != (iconv_t)-1 )
 457             iconv_close(m2w);
 458         if ( w2m != (iconv_t)-1 )
 459             iconv_close(w2m);
 460     }
 461
 462     size_t MB2WC(wchar_t *buf, const char *psz, size_t n)
 463     {
 464         size_t inbuf = strlen(psz);
 465         size_t outbuf = n * SIZEOF_WCHAR_T;
 466         size_t res, cres;
 467         // VS: Use these instead of psz, buf because iconv() modifies its arguments:
 468         wchar_t *bufPtr = buf;
 469         const char *pszPtr = psz;
 470
 471         if (buf)
 472         {
 473             // have destination buffer, convert there
 474 #ifdef WX_ICONV_TAKES_CHAR
 475             cres = iconv(m2w, (char**)&pszPtr, &inbuf, (char**)&bufPtr, &outbuf);
 476 #else
 477             cres = iconv(m2w, &pszPtr, &inbuf, (char**)&bufPtr, &outbuf);
 478 #endif
 479             res = n - (outbuf / SIZEOF_WCHAR_T);
 480             // convert to native endianness
 481 #ifdef WC_NEED_BSWAP
 482             WC_BSWAP(buf /* _not_ bufPtr */, res)
 483 #endif
 484         }
 485         else
 486         {
 487             // no destination buffer... convert using temp buffer
 488             // to calculate destination buffer requirement
 489             wchar_t tbuf[8];
 490             res = 0;
 491             do {
 492                 bufPtr = tbuf; outbuf = 8*SIZEOF_WCHAR_T;
 493 #ifdef WX_ICONV_TAKES_CHAR
 494                 cres = iconv( m2w, (char**)&pszPtr, &inbuf, (char**)&bufPtr, &outbuf );
 495 #else
 496                 cres = iconv( m2w, &pszPtr, &inbuf, (char**)&bufPtr, &outbuf );
 497 #endif
 498                 res += 8-(outbuf/SIZEOF_WCHAR_T);
 499             } while ((cres==(size_t)-1) && (errno==E2BIG));
 500         }
 501
 502         if (ICONV_FAILED(cres, inbuf))
 503             return (size_t)-1;
 504
 505         return res;
 506     }
 507
 508     size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
 509     {
 510 #if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
 511         size_t inbuf = std::wcslen(psz) * SIZEOF_WCHAR_T;
 512 #else
 513         size_t inbuf = ::wcslen(psz) * SIZEOF_WCHAR_T;
 514 #endif
 515         size_t outbuf = n;
 516         size_t res, cres;
 517
 518 #ifdef WC_NEED_BSWAP
 519         // need to copy to temp buffer to switch endianness
 520         // this absolutely doesn't rock!
 521         // (no, doing WC_BSWAP twice on the original buffer won't help, as it
 522         //  could be in read-only memory, or be accessed in some other thread)
 523         wchar_t*tmpbuf=(wchar_t*)malloc((inbuf+1)*SIZEOF_WCHAR_T);
 524         memcpy(tmpbuf,psz,(inbuf+1)*SIZEOF_WCHAR_T);
 525         WC_BSWAP(tmpbuf, inbuf)
 526         psz=tmpbuf;
 527 #endif
 528         if (buf)
 529         {
 530             // have destination buffer, convert there
 531 #ifdef WX_ICONV_TAKES_CHAR
 532             cres = iconv( w2m, (char**)&psz, &inbuf, &buf, &outbuf );
 533 #else
 534             cres = iconv( w2m, (const char**)&psz, &inbuf, &buf, &outbuf );
 535 #endif
 536             res = n-outbuf;
 537         }
 538         else
 539         {
 540             // no destination buffer... convert using temp buffer
 541             // to calculate destination buffer requirement
 542             char tbuf[16];
 543             res = 0;
 544             do {
 545                 buf = tbuf; outbuf = 16;
 546 #ifdef WX_ICONV_TAKES_CHAR
 547                 cres = iconv( w2m, (char**)&psz, &inbuf, &buf, &outbuf );
 548 #else
 549                 cres = iconv( w2m, (const char**)&psz, &inbuf, &buf, &outbuf );
 550 #endif
 551                 res += 16 - outbuf;
 552             } while ((cres==(size_t)-1) && (errno==E2BIG));
 553         }
 554 #ifdef WC_NEED_BSWAP
 555         free(tmpbuf);
 556 #endif
 557         if (ICONV_FAILED(cres, inbuf))
 558             return (size_t)-1;
 559
 560         return res;
 561     }
 562
 563     bool usable()
 564         { return (m2w != (iconv_t)-1) && (w2m != (iconv_t)-1); }
 565
 566 public:
 567     iconv_t m2w, w2m;
 568 };
 569 #endif
 570
 571 #ifdef __WIN32__
 572 class CP_CharSet : public wxCharacterSet
 573 {
 574 public:
 575     CP_CharSet(const wxChar*name)
 576         : wxCharacterSet(name), CodePage(CharsetToCodepage(name)) {}
 577
 578     size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
 579     {
 580         size_t len = MultiByteToWideChar(CodePage,0,psz,-1,buf,buf?n:0);
 581         return len ? len : (size_t)-1;
 582     }
 583
 584     size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
 585     {
 586         size_t len = WideCharToMultiByte(CodePage,0,psz,-1,buf,buf?n:0,NULL,NULL);
 587         return len ? len : (size_t)-1;
 588     }
 589
 590     bool usable()
 591         { return CodePage!=-1; }
 592
 593 public:
 594     long CodePage;
 595 };
 596 #endif
 597
 598 class EC_CharSet : public wxCharacterSet
 599 {
 600 public:
 601     // temporarily just use wxEncodingConverter stuff,
 602     // so that it works while a better implementation is built
 603     EC_CharSet(const wxChar*name) : wxCharacterSet(name), enc(wxFONTENCODING_SYSTEM)
 604     {
 605         if (name)
 606             enc = wxTheFontMapper->CharsetToEncoding(name, FALSE);
 607         m2w.Init(enc, wxFONTENCODING_UNICODE);
 608         w2m.Init(wxFONTENCODING_UNICODE, enc);
 609     }
 610
 611     size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
 612     {
 613         size_t inbuf = strlen(psz);
 614         if (buf) m2w.Convert(psz,buf);
 615         return inbuf;
 616     }
 617
 618     size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
 619     {
 620 #if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
 621         size_t inbuf = std::wcslen(psz);
 622 #else
 623         size_t inbuf = ::wcslen(psz);
 624 #endif
 625         if (buf)
 626             w2m.Convert(psz,buf);
 627
 628         return inbuf;
 629     }
 630
 631     bool usable()
 632         { return (enc!=wxFONTENCODING_SYSTEM) && (enc!=wxFONTENCODING_DEFAULT); }
 633
 634 public:
 635     wxFontEncoding enc;
 636     wxEncodingConverter m2w, w2m;
 637 };
 638
 639 static wxCharacterSet *wxGetCharacterSet(const wxChar *name)
 640 {
 641     wxCharacterSet *cset = NULL;
 642     if (name)
 643     {
 644         if (!wxStricmp(name, wxT("UTF8")) || !wxStricmp(name, wxT("UTF-8")))
 645         {
 646             cset = new ID_CharSet(name, &wxConvUTF8);
 647         }
 648         else
 649         {
 650 #ifdef HAVE_ICONV_H
 651             cset = new IC_CharSet(name); // may not take NULL
 652 #endif
 653         }
 654     }
 655
 656     if (cset && cset->usable()) return cset;
 657     if (cset) delete cset;
 658     cset = NULL;
 659 #ifdef __WIN32__
 660     cset = new CP_CharSet(name); // may take NULL
 661     if (cset->usable()) return cset;
 662 #endif
 663     if (cset) delete cset;
 664     cset = new EC_CharSet(name);
 665     if (cset->usable()) return cset;
 666     delete cset;
 667     wxLogError(_("Unknown encoding '%s'!"), name);
 668     return NULL;
 669 }
 670
 671 wxCSConv::wxCSConv(const wxChar *charset)
 672 {
 673     m_name = (wxChar *) NULL;
 674     m_cset = (wxCharacterSet *) NULL;
 675     m_deferred = TRUE;
 676     SetName(charset);
 677 }
 678
 679 wxCSConv::~wxCSConv()
 680 {
 681     if (m_name) free(m_name);
 682     if (m_cset) delete m_cset;
 683 }
 684
 685 void wxCSConv::SetName(const wxChar *charset)
 686 {
 687     if (charset)
 688     {
 689         m_name = wxStrdup(charset);
 690         m_deferred = TRUE;
 691     }
 692 }
 693
 694 void wxCSConv::LoadNow()
 695 {
 696     if (m_deferred)
 697     {
 698         if (!m_name)
 699         {
 700 #ifdef __UNIX__
 701 #if defined(HAVE_LANGINFO_H) && defined(CODESET)
 702             // GNU libc provides current character set this way
 703             char*alang = nl_langinfo(CODESET);
 704             if (alang)
 705             {
 706                 SetName(wxConvLibc.cMB2WX(alang));
 707             }
 708             else
 709 #endif
 710             {
 711                 // if we can't get at the character set directly,
 712                 // try to see if it's in the environment variables
 713                 // (in most cases this won't work, but I was out of ideas)
 714                 wxChar *lang = wxGetenv(wxT("LC_ALL"));
 715                 if (!lang) lang = wxGetenv(wxT("LC_CTYPE"));
 716                 if (!lang) lang = wxGetenv(wxT("LANG"));
 717                 wxChar *dot = lang ? wxStrchr(lang, wxT('.')) : (wxChar *)NULL;
 718                 if (dot) SetName(dot+1);
 719             }
 720 #endif
 721         }
 722         m_cset = wxGetCharacterSet(m_name);
 723         m_deferred = FALSE;
 724     }
 725 }
 726
 727 size_t wxCSConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
 728 {
 729     ((wxCSConv *)this)->LoadNow(); // discard constness
 730
 731     if (m_cset)
 732         return m_cset->MB2WC(buf, psz, n);
 733
 734     // latin-1 (direct)
 735     size_t len=strlen(psz);
 736
 737     if (buf)
 738     {
 739         for (size_t c=0; c<=len; c++)
 740             buf[c] = (unsigned char)(psz[c]);
 741     }
 742
 743     return len;
 744 }
 745
 746 size_t wxCSConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
 747 {
 748     ((wxCSConv *)this)->LoadNow(); // discard constness
 749
 750     if (m_cset)
 751         return m_cset->WC2MB(buf, psz, n);
 752
 753     // latin-1 (direct)
 754 #if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
 755     size_t len=std::wcslen(psz);
 756 #else
 757     size_t len=::wcslen(psz);
 758 #endif
 759     if (buf)
 760     {
 761         for (size_t c=0; c<=len; c++)
 762             buf[c] = (psz[c]>0xff) ? '?' : psz[c];
 763     }
 764
 765     return len;
 766 }
 767
 768 #ifdef HAVE_ICONV_H
 769 class IC_CharSetConverter
 770 {
 771 public:
 772     IC_CharSetConverter(IC_CharSet*from,IC_CharSet*to)
 773         { cnv = iconv_open(wxConvLibc.cWX2MB(to->cname),wxConvLibc.cWX2MB(from->cname)); }
 774
 775     ~IC_CharSetConverter()
 776         { if (cnv!=(iconv_t)-1) iconv_close(cnv); }
 777
 778     size_t Convert(char*buf, const char*psz, size_t n)
 779     {
 780         size_t inbuf = strlen(psz);
 781         size_t outbuf = n;
 782 #ifdef WX_ICONV_TAKES_CHAR
 783         size_t res = iconv( cnv, (char**)&psz, &inbuf, &buf, &outbuf );
 784 #else
 785         size_t res = iconv( cnv, &psz, &inbuf, &buf, &outbuf );
 786 #endif
 787         if (res==(size_t)-1) return (size_t)-1;
 788         return n-outbuf;
 789     }
 790
 791 public:
 792     iconv_t cnv;
 793 };
 794 #endif
 795
 796 class EC_CharSetConverter
 797 {
 798 public:
 799     EC_CharSetConverter(EC_CharSet*from,EC_CharSet*to)
 800         { cnv.Init(from->enc,to->enc); }
 801
 802     size_t Convert(char*buf, const char*psz, size_t n)
 803     {
 804         size_t inbuf = strlen(psz);
 805         if (buf) cnv.Convert(psz,buf);
 806         return inbuf;
 807     }
 808
 809 public:
 810     wxEncodingConverter cnv;
 811 };
 812
 813 #else // !wxUSE_WCHAR_T
 814
 815 // ----------------------------------------------------------------------------
 816 // stand-ins in absence of wchar_t
 817 // ----------------------------------------------------------------------------
 818
 819 WXDLLEXPORT_DATA(wxMBConv) wxConvLibc, wxConvFile;
 820
 821 #endif // wxUSE_WCHAR_T
 822
 823