src/common/intl.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        intl.cpp
   3 // Purpose:     Internationalization and localisation for wxWindows
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     29/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declaration
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21 #pragma implementation "intl.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 // standard headers
  32 #include  <locale.h>
  33
  34 // wxWindows
  35 #include "wx/defs.h"
  36 #include "wx/string.h"
  37 #include "wx/intl.h"
  38 #include "wx/file.h"
  39 #include "wx/log.h"
  40 #include "wx/utils.h"
  41
  42 #include <stdlib.h>
  43
  44 // ----------------------------------------------------------------------------
  45 // constants
  46 // ----------------------------------------------------------------------------
  47
  48 // magic number identifying the .mo format file
  49 const size_t32 MSGCATALOG_MAGIC    = 0x950412de;
  50 const size_t32 MSGCATALOG_MAGIC_SW = 0xde120495;
  51
  52 // extension of ".mo" files
  53 #define MSGCATALOG_EXTENSION  ".mo"
  54
  55 // ----------------------------------------------------------------------------
  56 // global functions
  57 // ----------------------------------------------------------------------------
  58
  59 // suppress further error messages about missing translations
  60 // (if you don't have one catalog file, you wouldn't like to see the
  61 //  error message for each string in it, so normally it's given only
  62 //  once)
  63 void wxSuppressTransErrors();
  64
  65 // restore the logging
  66 void wxRestoreTransErrors();
  67
  68 // get the current state
  69 bool wxIsLoggingTransErrors();
  70
  71 // get the current locale object (## may be NULL!)
  72 extern wxLocale *wxSetLocale(wxLocale *pLocale);
  73
  74 // ----------------------------------------------------------------------------
  75 // wxMsgCatalog corresponds to one disk-file message catalog.
  76 //
  77 // This is a "low-level" class and is used only by wxLocale (that's why
  78 // it's designed to be stored in a linked list)
  79 // ----------------------------------------------------------------------------
  80
  81 class wxMsgCatalog
  82 {
  83 public:
  84   // ctor & dtor
  85   wxMsgCatalog();
  86  ~wxMsgCatalog();
  87
  88   // load the catalog from disk (szDirPrefix corresponds to language)
  89   bool Load(const char *szDirPrefix, const char *szName);
  90   bool IsLoaded() const { return m_pData != NULL; }
  91
  92   // get name of the catalog
  93   const char *GetName() const { return m_pszName; }
  94
  95   // get the translated string: returns NULL if not found
  96   const char *GetString(const char *sz) const;
  97
  98   // public variable pointing to the next element in a linked list (or NULL)
  99   wxMsgCatalog *m_pNext;
 100
 101 private:
 102   // this implementation is binary compatible with GNU gettext() version 0.10
 103
 104   // an entry in the string table
 105   struct wxMsgTableEntry
 106   {
 107     size_t32   nLen;           // length of the string
 108     size_t32   ofsString;      // pointer to the string
 109   };
 110
 111   // header of a .mo file
 112   struct wxMsgCatalogHeader
 113   {
 114     size_t32  magic,          // offset +00:  magic id
 115             revision,       //        +04:  revision
 116             numStrings;     //        +08:  number of strings in the file
 117     size_t32  ofsOrigTable,   //        +0C:  start of original string table
 118             ofsTransTable;  //        +10:  start of translated string table
 119     size_t32  nHashSize,      //        +14:  hash table size
 120             ofsHashTable;   //        +18:  offset of hash table start
 121   };
 122
 123   // all data is stored here, NULL if no data loaded
 124   size_t8 *m_pData;
 125
 126   // data description
 127   size_t32            m_numStrings,   // number of strings in this domain
 128                     m_nHashSize;    // number of entries in hash table
 129   size_t32           *m_pHashTable;   // pointer to hash table
 130   wxMsgTableEntry  *m_pOrigTable,   // pointer to original   strings
 131                    *m_pTransTable;  //            translated
 132
 133   const char *StringAtOfs(wxMsgTableEntry *pTable, size_t32 index) const
 134     { return (const char *)(m_pData + Swap(pTable[index].ofsString)); }
 135
 136   // utility functions
 137     // calculate the hash value of given string
 138   static inline size_t32 GetHash(const char *sz);
 139     // big<->little endian
 140   inline size_t32 Swap(size_t32 ui) const;
 141
 142   // internal state
 143   bool HasHashTable() const // true if hash table is present
 144     { return m_nHashSize > 2 && m_pHashTable != NULL; }
 145
 146   bool          m_bSwapped;   // wrong endianness?
 147
 148   char         *m_pszName;    // name of the domain
 149 };
 150
 151 // ----------------------------------------------------------------------------
 152 // global variables
 153 // ----------------------------------------------------------------------------
 154
 155 // the list of the directories to search for message catalog files
 156 static wxArrayString s_searchPrefixes;
 157
 158 // ============================================================================
 159 // implementation
 160 // ============================================================================
 161
 162 // ----------------------------------------------------------------------------
 163 // wxMsgCatalog class
 164 // ----------------------------------------------------------------------------
 165
 166 // calculate hash value using the so called hashpjw function by P.J. Weinberger
 167 // [see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools]
 168 size_t32 wxMsgCatalog::GetHash(const char *sz)
 169 {
 170   #define HASHWORDBITS 32     // the length of size_t32
 171
 172   size_t32 hval = 0;
 173   size_t32 g;
 174   while ( *sz != '\0' ) {
 175     hval <<= 4;
 176     hval += (size_t32)*sz++;
 177     g = hval & ((size_t32)0xf << (HASHWORDBITS - 4));
 178     if ( g != 0 ) {
 179       hval ^= g >> (HASHWORDBITS - 8);
 180       hval ^= g;
 181     }
 182   }
 183
 184   return hval;
 185 }
 186
 187 // swap the 2 halves of 32 bit integer if needed
 188 size_t32 wxMsgCatalog::Swap(size_t32 ui) const
 189 {
 190   return m_bSwapped ? (ui << 24) | ((ui & 0xff00) << 8) |
 191                       ((ui >> 8) & 0xff00) | (ui >> 24)
 192                     : ui;
 193 }
 194
 195 wxMsgCatalog::wxMsgCatalog()
 196 {
 197   m_pData   = NULL;
 198   m_pszName = NULL;
 199 }
 200
 201 wxMsgCatalog::~wxMsgCatalog()
 202 {
 203   wxDELETEA(m_pData);
 204   wxDELETEA(m_pszName);
 205 }
 206
 207 // small class to suppress the translation erros until exit from current scope
 208 class NoTransErr
 209 {
 210 public:
 211     NoTransErr() { wxSuppressTransErrors(); }
 212    ~NoTransErr() { wxRestoreTransErrors();  }
 213 };
 214
 215 // return all directories to search for given prefix
 216 static wxString GetAllMsgCatalogSubdirs(const char *prefix,
 217                                         const char *lang)
 218 {
 219     wxString searchPath;
 220
 221     // search first in prefix/fr/LC_MESSAGES, then in prefix/fr and finally in
 222     // prefix (assuming the language is 'fr')
 223     searchPath << prefix << wxFILE_SEP_PATH << lang << wxFILE_SEP_PATH
 224                          << "LC_MESSAGES" << wxPATH_SEP
 225                << prefix << wxFILE_SEP_PATH << lang << wxPATH_SEP
 226                << prefix << wxPATH_SEP;
 227
 228     return searchPath;
 229 }
 230
 231 // construct the search path for the given language
 232 static wxString GetFullSearchPath(const char *lang)
 233 {
 234     wxString searchPath;
 235
 236     // first take the entries explicitly added by the program
 237     size_t count = s_searchPrefixes.Count();
 238     for ( size_t n = 0; n < count; n++ )
 239     {
 240         searchPath << GetAllMsgCatalogSubdirs(s_searchPrefixes[n], lang)
 241                    << wxPATH_SEP;
 242     }
 243
 244     // then take the current directory
 245     // FIXME it should be the directory of the executable
 246     searchPath << GetAllMsgCatalogSubdirs(".", lang) << wxPATH_SEP;
 247
 248     // and finally add some standard ones
 249     searchPath
 250         << GetAllMsgCatalogSubdirs("/usr/share/locale", lang) << wxPATH_SEP
 251         << GetAllMsgCatalogSubdirs("/usr/lib/locale", lang) << wxPATH_SEP
 252         << GetAllMsgCatalogSubdirs("/usr/local/share/locale", lang);
 253
 254     return searchPath;
 255 }
 256
 257 // open disk file and read in it's contents
 258 bool wxMsgCatalog::Load(const char *szDirPrefix, const char *szName)
 259 {
 260   // FIXME VZ: I forgot the exact meaning of LC_PATH - anyone to remind me?
 261 #if 0
 262   const char *pszLcPath = getenv("LC_PATH");
 263   if ( pszLcPath != NULL )
 264       strPath += pszLcPath + wxString(szDirPrefix) + MSG_PATH;
 265 #endif // 0
 266
 267   wxString searchPath = GetFullSearchPath(szDirPrefix);
 268   const char *sublocale = strchr(szDirPrefix, '_');
 269   if ( sublocale )
 270   {
 271       // also add just base locale name: for things like "fr_BE" (belgium
 272       // french) we should use "fr" if no belgium specific message catalogs
 273       // exist
 274       searchPath << GetFullSearchPath(wxString(szDirPrefix).
 275                                       Left((size_t)(sublocale - szDirPrefix)))
 276                  << wxPATH_SEP;
 277   }
 278
 279   wxString strFile = szName;
 280   strFile += MSGCATALOG_EXTENSION;
 281
 282   // don't give translation errors here because the wxstd catalog might
 283   // not yet be loaded (and it's normal)
 284   //
 285   // (we're using an object because we have several return paths)
 286   NoTransErr noTransErr;
 287
 288   wxLogVerbose(_("looking for catalog '%s' in path '%s'."),
 289                szName, searchPath.c_str());
 290
 291   wxString strFullName;
 292   if ( !wxFindFileInPath(&strFullName, searchPath, strFile) ) {
 293     wxLogWarning(_("catalog file for domain '%s' not found."), szName);
 294     return FALSE;
 295   }
 296
 297   // open file
 298   wxLogVerbose(_("using catalog '%s' from '%s'."),
 299              szName, strFullName.c_str());
 300
 301   wxFile fileMsg(strFullName);
 302   if ( !fileMsg.IsOpened() )
 303     return FALSE;
 304
 305   // get the file size
 306   off_t nSize = fileMsg.Length();
 307   if ( nSize == wxInvalidOffset )
 308     return FALSE;
 309
 310   // read the whole file in memory
 311   m_pData = new size_t8[nSize];
 312   if ( fileMsg.Read(m_pData, nSize) != nSize ) {
 313     wxDELETEA(m_pData);
 314     return FALSE;
 315   }
 316
 317   // examine header
 318   bool bValid = (size_t)nSize > sizeof(wxMsgCatalogHeader);
 319
 320   wxMsgCatalogHeader *pHeader = (wxMsgCatalogHeader *)m_pData;
 321   if ( bValid ) {
 322     // we'll have to swap all the integers if it's true
 323     m_bSwapped = pHeader->magic == MSGCATALOG_MAGIC_SW;
 324
 325     // check the magic number
 326     bValid = m_bSwapped || pHeader->magic == MSGCATALOG_MAGIC;
 327   }
 328
 329   if ( !bValid ) {
 330     // it's either too short or has incorrect magic number
 331     wxLogWarning(_("'%s' is not a valid message catalog."), strFullName.c_str());
 332
 333     wxDELETEA(m_pData);
 334     return FALSE;
 335   }
 336
 337   // initialize
 338   m_numStrings  = Swap(pHeader->numStrings);
 339   m_pOrigTable  = (wxMsgTableEntry *)(m_pData +
 340                    Swap(pHeader->ofsOrigTable));
 341   m_pTransTable = (wxMsgTableEntry *)(m_pData +
 342                    Swap(pHeader->ofsTransTable));
 343
 344   m_nHashSize   = Swap(pHeader->nHashSize);
 345   m_pHashTable  = (size_t32 *)(m_pData + Swap(pHeader->ofsHashTable));
 346
 347   m_pszName = new char[strlen(szName) + 1];
 348   strcpy(m_pszName, szName);
 349
 350   // everything is fine
 351   return TRUE;
 352 }
 353
 354 // search for a string
 355 const char *wxMsgCatalog::GetString(const char *szOrig) const
 356 {
 357   if ( szOrig == NULL )
 358     return NULL;
 359
 360   if ( HasHashTable() ) {   // use hash table for lookup if possible
 361     size_t32 nHashVal = GetHash(szOrig);
 362     size_t32 nIndex   = nHashVal % m_nHashSize;
 363
 364     size_t32 nIncr = 1 + (nHashVal % (m_nHashSize - 2));
 365
 366     while ( TRUE ) {
 367       size_t32 nStr = Swap(m_pHashTable[nIndex]);
 368       if ( nStr == 0 )
 369         return NULL;
 370
 371       if ( strcmp(szOrig, StringAtOfs(m_pOrigTable, nStr - 1)) == 0 )
 372         return StringAtOfs(m_pTransTable, nStr - 1);
 373
 374       if ( nIndex >= m_nHashSize - nIncr)
 375         nIndex -= m_nHashSize - nIncr;
 376       else
 377         nIndex += nIncr;
 378     }
 379   }
 380   else {                    // no hash table: use default binary search
 381     size_t32 bottom = 0,
 382            top    = m_numStrings,
 383            current;
 384     while ( bottom < top ) {
 385       current = (bottom + top) / 2;
 386       int res = strcmp(szOrig, StringAtOfs(m_pOrigTable, current));
 387       if ( res < 0 )
 388         top = current;
 389       else if ( res > 0 )
 390         bottom = current + 1;
 391       else    // found!
 392         return StringAtOfs(m_pTransTable, current);
 393     }
 394   }
 395
 396   // not found
 397   return NULL;
 398 }
 399
 400 // ----------------------------------------------------------------------------
 401 // wxLocale
 402 // ----------------------------------------------------------------------------
 403
 404 wxLocale::wxLocale()
 405 {
 406   m_pszOldLocale = NULL;
 407   m_pMsgCat = NULL;
 408 }
 409
 410 // NB: this function has (desired) side effect of changing current locale
 411 bool wxLocale::Init(const char *szName,
 412                     const char *szShort,
 413                     const char *szLocale,
 414                     bool        bLoadDefault)
 415 {
 416   m_strLocale = szName;
 417   m_strShort = szShort;
 418
 419   // change current locale (default: same as long name)
 420   if ( szLocale == NULL )
 421     szLocale = szName;
 422   m_pszOldLocale = setlocale(LC_ALL, szLocale);
 423   if ( m_pszOldLocale == NULL )
 424     wxLogError(_("locale '%s' can not be set."), szLocale);
 425
 426   // the short name will be used to look for catalog files as well,
 427   // so we need something here
 428   if ( m_strShort.IsEmpty() ) {
 429     // FIXME I don't know how these 2 letter abbreviations are formed,
 430     //       this wild guess is surely wrong
 431     m_strShort = wxToLower(szLocale[0]) + wxToLower(szLocale[1]);
 432   }
 433
 434   // save the old locale to be able to restore it later
 435   m_pOldLocale = wxSetLocale(this);
 436
 437   // load the default catalog with wxWindows standard messages
 438   m_pMsgCat = NULL;
 439   bool bOk = TRUE;
 440   if ( bLoadDefault )
 441     bOk = AddCatalog("wxstd");
 442
 443   return bOk;
 444 }
 445
 446 void wxLocale::AddCatalogLookupPathPrefix(const wxString& prefix)
 447 {
 448     if ( s_searchPrefixes.Index(prefix) == wxNOT_FOUND )
 449     {
 450         s_searchPrefixes.Add(prefix);
 451     }
 452     //else: already have it
 453 }
 454
 455 // clean up
 456 wxLocale::~wxLocale()
 457 {
 458     // free memory
 459     wxMsgCatalog *pTmpCat;
 460     while ( m_pMsgCat != NULL ) {
 461         pTmpCat = m_pMsgCat;
 462         m_pMsgCat = m_pMsgCat->m_pNext;
 463         delete pTmpCat;
 464     }
 465
 466     // restore old locale
 467     wxSetLocale(m_pOldLocale);
 468     setlocale(LC_ALL, m_pszOldLocale);
 469 }
 470
 471 // get the translation of given string in current locale
 472 const char *wxLocale::GetString(const char *szOrigString,
 473                                 const char *szDomain) const
 474 {
 475   wxASSERT( szOrigString != NULL ); // would be pretty silly
 476
 477   const char *pszTrans = NULL;
 478
 479   wxMsgCatalog *pMsgCat;
 480   if ( szDomain != NULL ) {
 481     pMsgCat = FindCatalog(szDomain);
 482
 483     // does the catalog exist?
 484     if ( pMsgCat != NULL )
 485       pszTrans = pMsgCat->GetString(szOrigString);
 486   }
 487   else {
 488     // search in all domains
 489     for ( pMsgCat = m_pMsgCat; pMsgCat != NULL; pMsgCat = pMsgCat->m_pNext ) {
 490       pszTrans = pMsgCat->GetString(szOrigString);
 491       if ( pszTrans != NULL )   // take the first found
 492         break;
 493     }
 494   }
 495
 496   if ( pszTrans == NULL ) {
 497     if ( wxIsLoggingTransErrors() ) {
 498       // suppress further error messages if we're not debugging: this avoids
 499       // flooding the user with messages about each and every missing string if,
 500       // for example, a whole catalog file is missing.
 501
 502       // do it before calling LogWarning to prevent infinite recursion!
 503 #ifdef __WXDEBUG__
 504       NoTransErr noTransErr;
 505 #else // !debug
 506       wxSuppressTransErrors();
 507 #endif // debug/!debug
 508
 509       if ( szDomain != NULL )
 510       {
 511         wxLogWarning(_("string '%s' not found in domain '%s' for locale '%s'."),
 512                      szOrigString, szDomain, m_strLocale.c_str());
 513       }
 514       else
 515       {
 516         wxLogWarning(_("string '%s' not found in locale '%s'."),
 517                      szOrigString, m_strLocale.c_str());
 518       }
 519     }
 520
 521     return szOrigString;
 522   }
 523   else
 524     return pszTrans;
 525 }
 526
 527 // find catalog by name in a linked list, return NULL if !found
 528 wxMsgCatalog *wxLocale::FindCatalog(const char *szDomain) const
 529 {
 530 // linear search in the linked list
 531   wxMsgCatalog *pMsgCat;
 532   for ( pMsgCat = m_pMsgCat; pMsgCat != NULL; pMsgCat = pMsgCat->m_pNext ) {
 533     if ( Stricmp(pMsgCat->GetName(), szDomain) == 0 )
 534       return pMsgCat;
 535   }
 536
 537   return NULL;
 538 }
 539
 540 // check if the given catalog is loaded
 541 bool wxLocale::IsLoaded(const char *szDomain) const
 542 {
 543   return FindCatalog(szDomain) != NULL;
 544 }
 545
 546 // add a catalog to our linked list
 547 bool wxLocale::AddCatalog(const char *szDomain)
 548 {
 549   wxMsgCatalog *pMsgCat = new wxMsgCatalog;
 550
 551   if ( pMsgCat->Load(m_strShort, szDomain) ) {
 552     // add it to the head of the list so that in GetString it will
 553     // be searched before the catalogs added earlier
 554     pMsgCat->m_pNext = m_pMsgCat;
 555     m_pMsgCat = pMsgCat;
 556
 557     return TRUE;
 558   }
 559   else {
 560     // don't add it because it couldn't be loaded anyway
 561     delete pMsgCat;
 562
 563     return FALSE;
 564   }
 565 }
 566
 567 // ----------------------------------------------------------------------------
 568 // global functions and variables
 569 // ----------------------------------------------------------------------------
 570
 571 // translation errors logging
 572 // --------------------------
 573
 574 static bool gs_bGiveTransErrors = TRUE;
 575
 576 void wxSuppressTransErrors()
 577 {
 578   gs_bGiveTransErrors = FALSE;
 579 }
 580
 581 void wxRestoreTransErrors()
 582 {
 583   gs_bGiveTransErrors = TRUE;
 584 }
 585
 586 bool wxIsLoggingTransErrors()
 587 {
 588   return gs_bGiveTransErrors;
 589 }
 590
 591 // retrieve/change current locale
 592 // ------------------------------
 593
 594 // the current locale object
 595 wxLocale *g_pLocale = NULL;
 596
 597 wxLocale *wxGetLocale()
 598 {
 599   return g_pLocale;
 600 }
 601
 602 wxLocale *wxSetLocale(wxLocale *pLocale)
 603 {
 604   wxLocale *pOld = g_pLocale;
 605   g_pLocale = pLocale;
 606   return pOld;
 607 }