src/common/textfile.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        textfile.cpp
   3 // Purpose:     implementation of wxTextFile class
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     03.04.98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // headers
  14 // ============================================================================
  15
  16 #ifdef __GNUG__
  17 #pragma implementation "textfile.h"
  18 #endif
  19
  20 #include  "wx/wxprec.h"
  21
  22 #ifdef    __BORLANDC__
  23   #pragma hdrstop
  24 #endif  //__BORLANDC__
  25
  26 #include  <wx/string.h>
  27 #include  <wx/intl.h>
  28 #include  <wx/file.h>
  29 #include  <wx/log.h>
  30 #include  <wx/textfile.h>
  31
  32 // ============================================================================
  33 // wxTextFile class implementation
  34 // ============================================================================
  35
  36 // ----------------------------------------------------------------------------
  37 // static variables
  38 // ----------------------------------------------------------------------------
  39
  40 // default type is the native one
  41 const wxTextFile::Type wxTextFile::typeDefault = wxTextFile::
  42 #if   defined(__WINDOWS__)
  43   Type_Dos;
  44 #elif defined(__UNIX__)
  45   Type_Unix;
  46 #elif defined(__WXMAC__)
  47   Type_Mac;
  48 #else
  49   Type_None;
  50   #error  "wxTextFile: unsupported platform."
  51 #endif
  52
  53
  54 // ----------------------------------------------------------------------------
  55 // ctors & dtor
  56 // ----------------------------------------------------------------------------
  57
  58 wxTextFile::wxTextFile(const wxString& strFile) : m_strFile(strFile)
  59 {
  60 }
  61
  62 wxTextFile::~wxTextFile()
  63 {
  64   // m_file dtor called automatically
  65 }
  66
  67 // ----------------------------------------------------------------------------
  68 // file operations
  69 // ----------------------------------------------------------------------------
  70
  71 bool wxTextFile::Open(const wxString& strFile)
  72 {
  73   m_strFile = strFile;
  74   return Open();
  75 }
  76
  77 bool wxTextFile::Open()
  78 {
  79   // file name must be either given in ctor or in Open(const wxString&)
  80   wxASSERT( !m_strFile.IsEmpty() );
  81
  82   // open file in read-only mode
  83   if ( !m_file.Open(m_strFile) )
  84     return FALSE;
  85
  86   // read file into memory
  87   bool bRet = Read();
  88
  89   m_file.Close();
  90
  91   return bRet;
  92 }
  93
  94 // analyse some lines of the file trying to guess it's type.
  95 // if it fails, it assumes the native type for our platform.
  96 wxTextFile::Type wxTextFile::GuessType() const
  97 {
  98   // file should be opened and we must be in it's beginning
  99   wxASSERT( m_file.IsOpened() && m_file.Tell() == 0 );
 100
 101   // scan the file lines
 102   size_t nUnix = 0,     // number of '\n's alone
 103        nDos  = 0,     // number of '\r\n'
 104        nMac  = 0;     // number of '\r's
 105
 106   // we take MAX_LINES_SCAN in the beginning, middle and the end of file
 107   #define MAX_LINES_SCAN    (10)
 108   size_t nCount = m_aLines.Count() / 3,
 109        nScan =  nCount > 3*MAX_LINES_SCAN ? MAX_LINES_SCAN : nCount / 3;
 110
 111   #define   AnalyseLine(n)              \
 112     switch ( m_aTypes[n] ) {            \
 113       case Type_Unix: nUnix++; break;   \
 114       case Type_Dos:  nDos++;  break;   \
 115       case Type_Mac:  nMac++;  break;   \
 116       default: wxFAIL_MSG(_("unknown line terminator")); \
 117     }
 118
 119   size_t n;
 120   for ( n = 0; n < nScan; n++ )     // the beginning
 121     AnalyseLine(n);
 122   for ( n = (nCount - nScan)/2; n < (nCount + nScan)/2; n++ )
 123     AnalyseLine(n);
 124   for ( n = nCount - nScan; n < nCount; n++ )
 125     AnalyseLine(n);
 126
 127   #undef   AnalyseLine
 128
 129   // interpret the results (@@ far from being even 50% fool proof)
 130   if ( nDos + nUnix + nMac == 0 ) {
 131     // no newlines at all
 132     wxLogWarning(_("'%s' is probably a binary file."), m_strFile.c_str());
 133   }
 134   else {
 135     #define   GREATER_OF(t1, t2) n##t1 == n##t2 ? typeDefault               \
 136                                                 : n##t1 > n##t2 ? Type_##t1 \
 137                                                                 : Type_##t2
 138
 139     if ( nDos > nUnix )
 140       return GREATER_OF(Dos, Mac);
 141     else if ( nDos < nUnix )
 142       return GREATER_OF(Unix, Mac);
 143     else {
 144       // nDos == nUnix
 145       return nMac > nDos ? Type_Mac : typeDefault;
 146     }
 147
 148     #undef    GREATER_OF
 149   }
 150
 151   return typeDefault;
 152 }
 153
 154 bool wxTextFile::Read()
 155 {
 156   // file should be opened and we must be in it's beginning
 157   wxASSERT( m_file.IsOpened() && m_file.Tell() == 0 );
 158
 159   wxString str;
 160   char ch, chLast = '\0';
 161   char buf[1024];
 162   int n, nRead;
 163   while ( !m_file.Eof() ) {
 164     nRead = m_file.Read(buf, WXSIZEOF(buf));
 165     if ( nRead == wxInvalidOffset ) {
 166       // read error (error message already given in wxFile::Read)
 167       m_file.Close();
 168       return FALSE;
 169     }
 170
 171     for ( n = 0; n < nRead; n++ ) {
 172       ch = buf[n];
 173       switch ( ch ) {
 174         case '\n':
 175           // Dos/Unix line termination
 176           m_aLines.Add(str);
 177           m_aTypes.Add(chLast == '\r' ? Type_Dos : Type_Unix);
 178           str.Empty();
 179           chLast = '\n';
 180           break;
 181
 182         case '\r':
 183           if ( chLast == '\r' ) {
 184             // Mac empty line
 185             m_aLines.Add("");
 186             m_aTypes.Add(Type_Mac);
 187           }
 188           else
 189             chLast = '\r';
 190           break;
 191
 192         default:
 193           if ( chLast == '\r' ) {
 194             // Mac line termination
 195             m_aLines.Add(str);
 196             m_aTypes.Add(Type_Mac);
 197             chLast = ch;
 198             str = ch;
 199           }
 200           else {
 201             // add to the current line
 202             str += ch;
 203           }
 204       }
 205     }
 206   }
 207
 208   // anything in the last line?
 209   if ( !str.IsEmpty() ) {
 210     m_aTypes.Add(Type_None);  // no line terminator
 211     m_aLines.Add(str);
 212   }
 213
 214   return TRUE;
 215 }
 216
 217 bool wxTextFile::Write(Type typeNew)
 218 {
 219   wxTempFile fileTmp(m_strFile);
 220
 221   if ( !fileTmp.IsOpened() ) {
 222     wxLogError(_("can't write file '%s' to disk."), m_strFile.c_str());
 223     return FALSE;
 224   }
 225
 226   size_t nCount = m_aLines.Count();
 227   for ( size_t n = 0; n < nCount; n++ ) {
 228     fileTmp.Write(m_aLines[n] +
 229                   GetEOL(typeNew == Type_None ? m_aTypes[n] : typeNew));
 230   }
 231
 232   // replace the old file with this one
 233   return fileTmp.Commit();
 234 }