implemented (more) correct <pre> handling

[wxWidgets.git] / src / common / strconv.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        strconv.cpp
// Purpose:     Unicode conversion classes
// Author:      Ove Kaaven, Robert Roebling, Vadim Zeitlin
// Modified by:
// Created:     29/01/98
// RCS-ID:      $Id$
// Copyright:   (c) 1999 Ove Kaaven, Robert Roebling, Vadim Zeitlin
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#ifdef __GNUG__
  #pragma implementation "strconv.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
  #pragma hdrstop
#endif

#ifdef __WXMSW__
  #include "wx/msw/private.h"
#endif

#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>

#ifdef __SALFORDC__
  #include <clib.h>
#endif

#ifdef HAVE_ICONV_H
  #include <iconv.h>
#endif
#ifdef HAVE_LANGINFO_H
  #include <langinfo.h>
#endif

#ifdef __WXMSW__
  #include <windows.h>
#endif

#include "wx/debug.h"
#include "wx/strconv.h"

#if defined(WORDS_BIGENDIAN) || defined(__STDC_ISO_10646__)
#define BSWAP_UCS4(str, len)
#define BSWAP_UCS2(str, len)
#else
#define BSWAP_UCS4(str, len) { unsigned _c; for (_c=0; _c<len; _c++) str[_c]=wxUINT32_SWAP_ALWAYS(str[_c]); }
#define BSWAP_UCS2(str, len) { unsigned _c; for (_c=0; _c<len; _c++) str[_c]=wxUINT16_SWAP_ALWAYS(str[_c]); }
#define WC_NEED_BSWAP
#endif
#define BSWAP_UTF32(str, len) BSWAP_UCS4(str, len)
#define BSWAP_UTF16(str, len) BSWAP_UCS2(str, len)

#if SIZEOF_WCHAR_T == 4
#define WC_NAME "UCS4"
#define WC_BSWAP BSWAP_UCS4
#elif SIZEOF_WCHAR_T == 2
#define WC_NAME "UTF16"
#define WC_BSWAP BSWAP_UTF16
#define WC_UTF16
#endif

// ----------------------------------------------------------------------------
// globals
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv *) wxConvCurrent = &wxConvLibc;

// ============================================================================
// implementation
// ============================================================================

#if wxUSE_WCHAR_T

#ifdef WC_UTF16

static size_t encode_utf16(wxUint32 input,wxUint16*output)
{
  if (input<=0xffff) {
    if (output) *output++ = input;
    return 1;
  } else
  if (input>=0x110000) {
    return (size_t)-1;
  } else {
    if (output) {
      *output++ = (input >> 10)+0xd7c0;
      *output++ = (input&0x3ff)+0xdc00;
    }
    return 2;
  }
}

static size_t decode_utf16(wxUint16*input,wxUint32&output)
{
  if ((*input<0xd800) || (*input>0xdfff)) {
    output = *input;
    return 1;
  } else
  if ((input[1]<0xdc00) || (input[1]>=0xdfff)) {
    output = *input;
    return (size_t)-1;
  } else {
    output = ((input[0] - 0xd7c0) << 10) + (input[1] - 0xdc00);
    return 2;
  }
}

#endif // WC_UTF16

// ----------------------------------------------------------------------------
// wxMBConv
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv) wxConvLibc;

size_t wxMBConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
    return wxMB2WC(buf, psz, n);
}

size_t wxMBConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
    return wxWC2MB(buf, psz, n);
}

const wxWCharBuffer wxMBConv::cMB2WC(const char *psz) const
{
    if (psz)
    {
        size_t nLen = MB2WC((wchar_t *) NULL, psz, 0);
        if (nLen == (size_t)-1)
            return wxWCharBuffer((wchar_t *) NULL);
        wxWCharBuffer buf(nLen);
        MB2WC((wchar_t *)(const wchar_t *) buf, psz, nLen);
        return buf;
    }
    else
        return wxWCharBuffer((wchar_t *) NULL);
}

const wxCharBuffer wxMBConv::cWC2MB(const wchar_t *psz) const
{
    if (psz)
    {
        size_t nLen = WC2MB((char *) NULL, psz, 0);
        if (nLen == (size_t)-1)
            return wxCharBuffer((char *) NULL);
        wxCharBuffer buf(nLen);
        WC2MB((char *)(const char *) buf, psz, nLen);
        return buf;
    }
    else
        return wxCharBuffer((char *) NULL);
}

// ----------------------------------------------------------------------------
// standard file conversion
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvFile) wxConvFile;

// just use the libc conversion for now
size_t wxMBConvFile::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
    return wxMB2WC(buf, psz, n);
}

size_t wxMBConvFile::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
    return wxWC2MB(buf, psz, n);
}

// ----------------------------------------------------------------------------
// standard gdk conversion
// ----------------------------------------------------------------------------

#ifdef __WXGTK12__

WXDLLEXPORT_DATA(wxMBConvGdk) wxConvGdk;

#include <gdk/gdk.h>

size_t wxMBConvGdk::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
  if (buf) {
    return gdk_mbstowcs((GdkWChar *)buf, psz, n);
  } else {
    GdkWChar *nbuf = new GdkWChar[n=strlen(psz)];
    size_t len = gdk_mbstowcs(nbuf, psz, n);
    delete [] nbuf;
    return len;
  }
}

size_t wxMBConvGdk::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
  char *mbstr = gdk_wcstombs((GdkWChar *)psz);
  size_t len = mbstr ? strlen(mbstr) : 0;
  if (buf) {
    if (len > n) len = n;
    memcpy(buf, psz, len);
    if (len < n) buf[len] = 0;
  }
  return len;
}

#endif // GTK > 1.0

// ----------------------------------------------------------------------------
// UTF-7
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvUTF7) wxConvUTF7;

#if 0
static char utf7_setD[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                        "abcdefghijklmnopqrstuvwxyz"
                        "0123456789'(),-./:?";
static char utf7_setO[]="!\"#$%&*;<=>@[]^_`{|}";
static char utf7_setB[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                        "abcdefghijklmnopqrstuvwxyz"
                        "0123456789+/";
#endif

// TODO: write actual implementations of UTF-7 here
size_t wxMBConvUTF7::MB2WC(wchar_t * WXUNUSED(buf),
                           const char * WXUNUSED(psz),
                           size_t WXUNUSED(n)) const
{
  return 0;
}

size_t wxMBConvUTF7::WC2MB(char * WXUNUSED(buf),
                           const wchar_t * WXUNUSED(psz),
                           size_t WXUNUSED(n)) const
{
  return 0;
}

// ----------------------------------------------------------------------------
// UTF-8
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvUTF8) wxConvUTF8;

static wxUint32 utf8_max[]={0x7f,0x7ff,0xffff,0x1fffff,0x3ffffff,0x7fffffff,0xffffffff};

size_t wxMBConvUTF8::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
  size_t len = 0;

  while (*psz && ((!buf) || (len<n))) {
    unsigned char cc=*psz++, fc=cc;
    unsigned cnt;
    for (cnt=0; fc&0x80; cnt++) fc<<=1;
    if (!cnt) {
      // plain ASCII char
      if (buf) *buf++=cc;
      len++;
    } else {
      cnt--;
      if (!cnt) {
        // invalid UTF-8 sequence
        return (size_t)-1;
      } else {
        unsigned ocnt=cnt-1;
        wxUint32 res=cc&(0x3f>>cnt);
        while (cnt--) {
          cc = *psz++;
          if ((cc&0xC0)!=0x80) {
            // invalid UTF-8 sequence
            return (size_t)-1;
          }
          res=(res<<6)|(cc&0x3f);
        }
        if (res<=utf8_max[ocnt]) {
          // illegal UTF-8 encoding
          return (size_t)-1;
        }
#ifdef WC_UTF16
        size_t pa = encode_utf16(res, buf);
        if (pa == (size_t)-1)
          return (size_t)-1;
        if (buf) buf+=pa;
        len+=pa;
#else
        if (buf) *buf++=res;
        len++;
#endif
      }
    }
  }
  if (buf && (len<n)) *buf = 0;
  return len;
}

size_t wxMBConvUTF8::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
  size_t len = 0;

  while (*psz && ((!buf) || (len<n))) {
    wxUint32 cc;
#ifdef WC_UTF16
    size_t pa = decode_utf16(psz,cc);
    psz += (pa == (size_t)-1) ? 1 : pa;
#else
    cc=(*psz++)&0x7fffffff;
#endif
    unsigned cnt;
    for (cnt=0; cc>utf8_max[cnt]; cnt++);
    if (!cnt) {
      // plain ASCII char
      if (buf) *buf++=cc;
      len++;
    } else {
      len+=cnt+1;
      if (buf) {
        *buf++=(-128>>cnt)|((cc>>(cnt*6))&(0x3f>>cnt));
        while (cnt--)
          *buf++=0x80|((cc>>(cnt*6))&0x3f);
      }
    }
  }
  if (buf && (len<n)) *buf = 0;
  return len;
}

// ----------------------------------------------------------------------------
// specified character set
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxCSConv) wxConvLocal((const wxChar *)NULL);

#include "wx/encconv.h"
#include "wx/fontmap.h"

// TODO: add some tables here
// - perhaps common encodings to common codepages (for Win32)
// - perhaps common encodings to objects ("UTF8" -> wxConvUTF8)
// - move wxEncodingConverter meat in here

#ifdef __WIN32__
#include "wx/msw/registry.h"
// this should work if M$ Internet Exploiter is installed
static long CharsetToCodepage(const wxChar *name)
{
    if (!name) 
        return GetACP();
        
    long CP=-1;
    
    wxString cn(name);
    do {
        wxString path( wxT("MIME\\Database\\Charset\\") );
        path += cn;
        wxRegKey key( wxRegKey::HKCR, path );

        /* two cases: either there's an AliasForCharset string,
         * or there are Codepage and InternetEncoding dwords.
         * The InternetEncoding gives us the actual encoding,
         * the Codepage just says which Windows character set to
         * use when displaying the data.
         */
        if (key.QueryValue( wxT("InternetEncoding"), &CP )) break;
        
        // no encoding, see if it's an alias
        if (!key.QueryValue( wxT("AliasForCharset"), cn )) break;
    } while (1);
    
    return CP;
}
#endif

class wxCharacterSet
{
public:
    wxCharacterSet(const wxChar*name)
        : cname(name) {}
    virtual ~wxCharacterSet()
        {}
    virtual size_t MB2WC(wchar_t*buf, const char*psz, size_t n) 
        { return (size_t)-1; }
    virtual size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
        { return (size_t)-1; }
    virtual bool usable()
        { return FALSE; }
public:
    const wxChar*cname;
};

class ID_CharSet : public wxCharacterSet
{
public:
    ID_CharSet(const wxChar*name,wxMBConv*cnv)
        : wxCharacterSet(name), work(cnv) {}
        
    size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
        { return work ? work->MB2WC(buf,psz,n) : (size_t)-1; }
        
    size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
        { return work ? work->WC2MB(buf,psz,n) : (size_t)-1; }
        
    bool usable()
        { return work!=NULL; }
public:
    wxMBConv*work;
};

#ifdef HAVE_ICONV_H
class IC_CharSet : public wxCharacterSet
{
public:
    IC_CharSet(const wxChar*name) 
        : wxCharacterSet(name), m2w((iconv_t)-1), w2m((iconv_t)-1) {}
    ~IC_CharSet()
    {
        if (m2w!=(iconv_t)-1) iconv_close(m2w);
        if (w2m!=(iconv_t)-1) iconv_close(w2m);
    }
    
    void LoadM2W() 
    { 
        if (m2w==(iconv_t)-1)
            m2w=iconv_open(WC_NAME,wxConvLibc.cWX2MB(cname));
    }
    
    void LoadW2M()
    { 
        if (w2m==(iconv_t)-1)
            w2m=iconv_open(wxConvLibc.cWX2MB(cname),WC_NAME);
    }
    
    size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
    {
        LoadM2W();
        size_t inbuf = strlen(psz);
        size_t outbuf = n*SIZEOF_WCHAR_T;
        size_t res, cres;
        fprintf(stderr,"IC Convert to WC using %s\n",(const char*)wxConvLibc.cWX2MB(cname));
        if (buf)
        {
            // have destination buffer, convert there
            cres = iconv( m2w, (char**)&psz, &inbuf, (char**)&buf, &outbuf );
            res = n-(outbuf/SIZEOF_WCHAR_T);
            // convert to native endianness
            WC_BSWAP(buf, res)
        }
        else
        {
            // no destination buffer... convert using temp buffer
            // to calculate destination buffer requirement
            wchar_t tbuf[8];
            res = 0;
            do {
                buf = tbuf; outbuf = 8*SIZEOF_WCHAR_T;
                cres = iconv( m2w, (char**)&psz, &inbuf, (char**)&buf, &outbuf );
                res += 8-(outbuf/SIZEOF_WCHAR_T);
            } while ((cres==(size_t)-1) && (errno==E2BIG));
        }
        
        if (cres==(size_t)-1)
            return (size_t)-1;
            
        return res;
    }
    
    size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
    {
        LoadW2M();
#if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
        size_t inbuf = std::wcslen(psz);
#else
        size_t inbuf = ::wcslen(psz);
#endif
        size_t outbuf = n;
        size_t res, cres;
        fprintf(stderr,"IC Convert from WC using %s\n",(const char*)wxConvLibc.cWX2MB(cname));
#ifdef WC_NEED_BSWAP
        // need to copy to temp buffer to switch endianness
        // this absolutely doesn't rock!
        // (no, doing WC_BSWAP twice on the original buffer won't help, as it
        //  could be in read-only memory, or be accessed in some other thread)
        wchar_t*tmpbuf=(wchar_t*)malloc((inbuf+1)*SIZEOF_WCHAR_T);
        memcpy(tmpbuf,psz,(inbuf+1)*SIZEOF_WCHAR_T);
        WC_BSWAP(tmpbuf, inbuf)
        psz=tmpbuf;
#endif
        if (buf)
        {
            // have destination buffer, convert there
            cres = iconv( w2m, (char**)&psz, &inbuf, &buf, &outbuf );
            res = n-outbuf;
        }
        else
        {
            // no destination buffer... convert using temp buffer
            // to calculate destination buffer requirement
            char tbuf[16];
            res = 0;
            do {
                buf = tbuf; outbuf = 16;
                cres = iconv( w2m, (char**)&psz, &inbuf, &buf, &outbuf );
                res += 16 - outbuf;
            } while ((cres==(size_t)-1) && (errno==E2BIG));
        }
#ifdef WC_NEED_BSWAP
        free(tmpbuf);
#endif
        if (cres==(size_t)-1)
            return (size_t)-1;
            
        return res;
    }
    
    bool usable()
        { return TRUE; }
  
public:
    iconv_t m2w, w2m;
};
#endif

#ifdef __WIN32__
class CP_CharSet : public wxCharacterSet
{
public:
    CP_CharSet(const wxChar*name) 
        : wxCharacterSet(name), CodePage(CharsetToCodepage(name)) {}
        
    size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
    {
        size_t len = MultiByteToWideChar(CodePage,0,psz,-1,buf,buf?n:0);
        return len ? len : (size_t)-1;
    }
    
    size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
    {
        size_t len = WideCharToMultiByte(CodePage,0,psz,-1,buf,buf?n:0,NULL,NULL);
        return len ? len : (size_t)-1;
    }
    
    bool usable()
        { return CodePage!=-1; }

public:
    long CodePage;
};
#endif

class EC_CharSet : public wxCharacterSet
{
public:
    // temporarily just use wxEncodingConverter stuff,
    // so that it works while a better implementation is built
    EC_CharSet(const wxChar*name) : wxCharacterSet(name), enc(wxFONTENCODING_SYSTEM)
    {
        if (name)
            enc = wxTheFontMapper->CharsetToEncoding(name, FALSE);
        m2w.Init(enc, wxFONTENCODING_UNICODE);
        w2m.Init(wxFONTENCODING_UNICODE, enc);
    }
    
    size_t MB2WC(wchar_t*buf, const char*psz, size_t n)
    {
        size_t inbuf = strlen(psz);
        fprintf(stderr,"EC Convert to WC using %d\n",enc);
        if (buf) m2w.Convert(psz,buf);
        return inbuf;
    }
    
    size_t WC2MB(char*buf, const wchar_t*psz, size_t n)
    {
#if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
        size_t inbuf = std::wcslen(psz);
#else
        size_t inbuf = ::wcslen(psz);
#endif
        fprintf(stderr,"EC Convert from WC using %d\n",enc);
        if (buf)
            w2m.Convert(psz,buf);
            
        return inbuf;
    }
    
    bool usable()
        { return (enc!=wxFONTENCODING_SYSTEM) && (enc!=wxFONTENCODING_DEFAULT); }

public:
    wxFontEncoding enc;
    wxEncodingConverter m2w, w2m;
};

static wxCharacterSet *wxGetCharacterSet(const wxChar *name)
{
    wxCharacterSet *cset = NULL;
    if (name)
    {
        if (!wxStricmp(name, wxT("UTF8")) || !wxStricmp(name, wxT("UTF-8")))
        {
            cset = new ID_CharSet(name, &wxConvUTF8);
        }
        else
        {
#ifdef HAVE_ICONV_H
            cset = new IC_CharSet(name); // may not take NULL
#endif
        }
    }
    
    if (cset && cset->usable()) return cset;
    if (cset) delete cset;
#ifdef __WIN32__
    cset = new CP_CharSet(name); // may take NULL
    if (cset->usable()) return cset;
#endif
    if (cset) delete cset;
    cset = new EC_CharSet(name);
    if (cset->usable()) return cset;
    delete cset;
    return NULL;
}

wxCSConv::wxCSConv(const wxChar *charset)
{
    m_name = (wxChar *) NULL;
    m_cset = (wxCharacterSet *) NULL;
    m_deferred = TRUE;
    SetName(charset);
}

wxCSConv::~wxCSConv()
{
    if (m_name) free(m_name);
    if (m_cset) delete m_cset;
}

void wxCSConv::SetName(const wxChar *charset)
{
    if (charset)
    {
        m_name = wxStrdup(charset);
        m_deferred = TRUE;
    }
}

void wxCSConv::LoadNow()
{
//  wxPrintf(wxT("Conversion request\n"));
    if (m_deferred)
    {
        if (!m_name)
        {
#ifdef __UNIX__
#if defined(HAVE_LANGINFO_H) && defined(CODESET)
            // GNU libc provides current character set this way
            char*alang = nl_langinfo(CODESET);
            if (alang)
            {
                SetName(wxConvLibc.cMB2WX(alang));
            }
            else
#endif
            {
                // if we can't get at the character set directly,
                // try to see if it's in the environment variables
                // (in most cases this won't work, but I was out of ideas)
                wxChar *lang = wxGetenv(wxT("LC_ALL"));
                if (!lang) lang = wxGetenv(wxT("LC_CTYPE"));
                if (!lang) lang = wxGetenv(wxT("LANG"));
                wxChar *dot = lang ? wxStrchr(lang, wxT('.')) : (wxChar *)NULL;
                if (dot) SetName(dot+1);
            }
#endif
        }
        m_cset = wxGetCharacterSet(m_name);
        m_deferred = FALSE;
    }
}

size_t wxCSConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
    ((wxCSConv *)this)->LoadNow(); // discard constness
    
    if (m_cset)
        return m_cset->MB2WC(buf, psz, n);

    // latin-1 (direct)
    size_t len=strlen(psz);
    
    if (buf)
    {
        for (size_t c=0; c<=len; c++)
            buf[c] = (unsigned char)(psz[c]);
    }
    
    return len;
}

size_t wxCSConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
    ((wxCSConv *)this)->LoadNow(); // discard constness
    
    if (m_cset)
        return m_cset->WC2MB(buf, psz, n);

    // latin-1 (direct)
#if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
    size_t len=std::wcslen(psz);
#else
    size_t len=::wcslen(psz);
#endif
    if (buf)
    {
        for (size_t c=0; c<=len; c++)
            buf[c] = (psz[c]>0xff) ? '?' : psz[c];
    }
    
    return len;
}

#ifdef HAVE_ICONV_H
class IC_CharSetConverter
{
public:
    IC_CharSetConverter(IC_CharSet*from,IC_CharSet*to)
        { cnv = iconv_open(wxConvLibc.cWX2MB(to->cname),wxConvLibc.cWX2MB(from->cname)); }
        
    ~IC_CharSetConverter()
        { if (cnv!=(iconv_t)-1) iconv_close(cnv); }
        
    size_t Convert(char*buf, const char*psz, size_t n)
    {
        size_t inbuf = strlen(psz);
        size_t outbuf = n;
        size_t res = iconv( cnv, (char**)&psz, &inbuf, &buf, &outbuf );
        if (res==(size_t)-1) return (size_t)-1;
        return n-outbuf;
    }

public:
    iconv_t cnv;
};
#endif

class EC_CharSetConverter
{
public:
    EC_CharSetConverter(EC_CharSet*from,EC_CharSet*to)
        { cnv.Init(from->enc,to->enc); }
        
    size_t Convert(char*buf, const char*psz, size_t n)
    {
        size_t inbuf = strlen(psz);
        if (buf) cnv.Convert(psz,buf);
        return inbuf;
    }
  
public:
    wxEncodingConverter cnv;
};

#else // !wxUSE_WCHAR_T

// ----------------------------------------------------------------------------
// stand-ins in absence of wchar_t
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv) wxConvLibc, wxConvFile;

#endif // wxUSE_WCHAR_T