config.cpp

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wxConfigPathChanger::wxConfigPathChanger(const wxConfigBase *pContainer,
                                         const wxString& strEntry)
{
  m_bChanged = false;
  m_pContainer = (wxConfigBase *)pContainer;

  // the path is everything which precedes the last slash
  wxString strPath = strEntry.BeforeLast(wxCONFIG_PATH_SEPARATOR);

  // except in the special case of "/keyname" when there is nothing before "/"
  if ( strPath.empty() &&
       ((!strEntry.empty()) && strEntry[0] == wxCONFIG_PATH_SEPARATOR) )
  {
    strPath = wxCONFIG_PATH_SEPARATOR;
  }

  if ( !strPath.empty() )
  {
    if ( m_pContainer->GetPath() != strPath )
    {
        // we do change the path so restore it later
        m_bChanged = true;

        /* JACS: work around a memory bug that causes an assert
           when using wxRegConfig, related to reference-counting.
           Can be reproduced by removing (const wxChar*) below and
           adding the following code to the config sample OnInit under
           Windows:

           pConfig->SetPath(wxT("MySettings"));
           pConfig->SetPath(wxT(".."));
           int value;
           pConfig->Read(_T("MainWindowX"), & value);
        */
        m_strOldPath = (const wxChar*) m_pContainer->GetPath();
        if ( *m_strOldPath.c_str() != wxCONFIG_PATH_SEPARATOR )
          m_strOldPath += wxCONFIG_PATH_SEPARATOR;
        m_pContainer->SetPath(strPath);
    }

    // in any case, use the just the name, not full path
    m_strName = strEntry.AfterLast(wxCONFIG_PATH_SEPARATOR);
  }
  else {
    // it's a name only, without path - nothing to do
    m_strName = strEntry;
  }
}

wxConfigPathChanger::~wxConfigPathChanger()
{
  // only restore path if it was changed
  if ( m_bChanged ) {
    m_pContainer->SetPath(m_strOldPath);
  }
}

#endif // wxUSE_CONFIG

// ----------------------------------------------------------------------------
// static & global functions
// ----------------------------------------------------------------------------

// understands both Unix and Windows (but only under Windows) environment
// variables expansion: i.e. $var, $(var) and ${var} are always understood
// and in addition under Windows %var% is also.

// don't change the values the enum elements: they must be equal
// to the matching [closing] delimiter.
enum Bracket
{
  Bracket_None,
  Bracket_Normal  = ')',
  Bracket_Curly   = '}',
#ifdef  __WXMSW__
  Bracket_Windows = '%',    // yeah, Windows people are a bit strange ;-)
#endif
  Bracket_Max
};

wxString wxExpandEnvVars(const wxString& str)
{
  wxString strResult;
  strResult.Alloc(str.Len());

  size_t m;
  for ( size_t n = 0; n < str.Len(); n++ ) {
    switch ( str[n] ) {
#ifdef  __WXMSW__
      case wxT('%'):
#endif  //WINDOWS
      case wxT('$'):
        {
          Bracket bracket;
          #ifdef  __WXMSW__
            if ( str[n] == wxT('%') )
              bracket = Bracket_Windows;
            else
          #endif  //WINDOWS
          if ( n == str.Len() - 1 ) {
            bracket = Bracket_None;
          }
          else {
            switch ( str[n + 1] ) {
              case wxT('('):
                bracket = Bracket_Normal;
                n++;                   // skip the bracket
                break;

              case wxT('{'):
                bracket = Bracket_Curly;
                n++;                   // skip the bracket
                break;

              default:
                bracket = Bracket_None;
            }
          }

          m = n + 1;

          while ( m < str.Len() && (wxIsalnum(str[m]) || str[m] == wxT('_')) )
            m++;

          wxString strVarName(str.c_str() + n + 1, m - n - 1);

#ifdef __WXWINCE__
          const wxChar *pszValue = NULL;
#else
          const wxChar *pszValue = wxGetenv(strVarName);
#endif
          if ( pszValue != NULL ) {
            strResult += pszValue;
          }
          else {
            // variable doesn't exist => don't change anything
            #ifdef  __WXMSW__
              if ( bracket != Bracket_Windows )
            #endif
                if ( bracket != Bracket_None )
                  strResult << str[n - 1];
            strResult << str[n] << strVarName;
          }

          // check the closing bracket
          if ( bracket != Bracket_None ) {
            if ( m == str.Len() || str[m] != (wxChar)bracket ) {
              // under MSW it's common to have '%' characters in the registry
              // and it's annoying to have warnings about them each time, so
              // ignroe them silently if they are not used for env vars
              //
              // under Unix, OTOH, this warning could be useful for the user to
              // understand why isn't the variable expanded as intended
              #ifndef __WXMSW__
                wxLogWarning(_("Environment variables expansion failed: missing '%c' at position %u in '%s'."),
                             (char)bracket, (unsigned int) (m + 1), str.c_str());
              #endif // __WXMSW__
            }
            else {
              // skip closing bracket unless the variables wasn't expanded
              if ( pszValue == NULL )
                strResult << (char)bracket;
              m++;
            }
          }

          n = m - 1;  // skip variable name
        }
        break;

      case '\\':
        // backslash can be used to suppress special meaning of % and $
        if ( n != str.Len() - 1 &&
                (str[n + 1] == wxT('%') || str[n + 1] == wxT('$')) ) {
          strResult += str[++n];

          break;
        }
        //else: fall through

      default:
        strResult += str[n];
    }
  }

  return strResult;
}

// this function is used to properly interpret '..' in path
void wxSplitPath(wxArrayString& aParts, const wxChar *sz)
{
  aParts.clear();

  wxString strCurrent;
  const wxChar *pc = sz;
  for ( ;; ) {
    if ( *pc == wxT('\0') || *pc == wxCONFIG_PATH_SEPARATOR ) {
      if ( strCurrent == wxT(".") ) {
        // ignore
      }
      else if ( strCurrent == wxT("..") ) {
        // go up one level
        if ( aParts.size() == 0 )
          wxLogWarning(_("'%s' has extra '..', ignored."), sz);
        else
          aParts.erase(aParts.end() - 1);

        strCurrent.Empty();
      }
      else if ( !strCurrent.empty() ) {
        aParts.push_back(strCurrent);
        strCurrent.Empty();
      }
      //else:
        // could log an error here, but we prefer to ignore extra '/'

      if ( *pc == wxT('\0') )
        break;
    }
    else
      strCurrent += *pc;

    pc++;
  }
}