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(__WXMSW__)
  43   Type_Dos;
  44 #elif defined(__UNIX__)
  45   Type_Unix;
  46 #elif defined(__MAC__)
  47   Type_Mac;
  48   // if you feel brave, remove the next line
  49   #error  "wxTextFile: code for Mac files is untested."
  50 #else
  51   Type_None;
  52   #error  "wxTextFile: unsupported platform."
  53 #endif
  54
  55
  56 // ----------------------------------------------------------------------------
  57 // ctors & dtor
  58 // ----------------------------------------------------------------------------
  59
  60 wxTextFile::wxTextFile(const wxString& strFile) : m_strFile(strFile)
  61 {
  62 }
  63
  64 wxTextFile::~wxTextFile()
  65 {
  66   // m_file dtor called automatically
  67 }
  68
  69 // ----------------------------------------------------------------------------
  70 // file operations
  71 // ----------------------------------------------------------------------------
  72
  73 bool wxTextFile::Open(const wxString& strFile)
  74 {
  75   m_strFile = strFile;
  76   return Open();
  77 }
  78
  79 bool wxTextFile::Open()
  80 {
  81   // file name must be either given in ctor or in Open(const wxString&)
  82   wxASSERT( !m_strFile.IsEmpty() );
  83
  84   // open file in read-only mode
  85   if ( !m_file.Open(m_strFile) )
  86     return FALSE;
  87
  88   // read file into memory
  89   bool bRet = Read();
  90
  91   m_file.Close();
  92
  93   return bRet;
  94 }
  95
  96 // analyse some lines of the file trying to guess it's type.
  97 // if it fails, it assumes the native type for our platform.
  98 wxTextFile::Type wxTextFile::GuessType() const
  99 {
 100   // file should be opened and we must be in it's beginning
 101   wxASSERT( m_file.IsOpened() && m_file.Tell() == 0 );
 102
 103   // scan the file lines
 104   uint nUnix = 0,     // number of '\n's alone
 105        nDos  = 0,     // number of '\r\n'
 106        nMac  = 0;     // number of '\r's
 107
 108   // we take MAX_LINES_SCAN in the beginning, middle and the end of file
 109   #define MAX_LINES_SCAN    (10)
 110   uint nCount = m_aLines.Count() / 3,
 111        nScan =  nCount > 3*MAX_LINES_SCAN ? MAX_LINES_SCAN : nCount / 3;
 112
 113   #define   AnalyseLine(n)              \
 114     switch ( m_aTypes[n] ) {            \
 115       case Type_Unix: nUnix++; break;   \
 116       case Type_Dos:  nDos++;  break;   \
 117       case Type_Mac:  nMac++;  break;   \
 118       default: wxFAIL_MSG("unknown line terminator"); \
 119     }
 120
 121   uint n;
 122   for ( n = 0; n < nScan; n++ )     // the beginning
 123     AnalyseLine(n);
 124   for ( n = (nCount - nScan)/2; n < (nCount + nScan)/2; n++ )
 125     AnalyseLine(n);
 126   for ( n = nCount - nScan; n < nCount; n++ )
 127     AnalyseLine(n);
 128
 129   #undef   AnalyseLine
 130
 131   // interpret the results (@@ far from being even 50% fool proof)
 132   if ( nDos + nUnix + nMac == 0 ) {
 133     // no newlines at all
 134     wxLogWarning("'%s' is probably a binary file.", m_strFile.c_str());
 135   }
 136   else {
 137     #define   GREATER_OF(t1, t2) n##t1 == n##t2 ? typeDefault               \
 138                                                 : n##t1 > n##t2 ? Type_##t1 \
 139                                                                 : Type_##t2
 140
 141     if ( nDos > nUnix )
 142       return GREATER_OF(Dos, Mac);
 143     else if ( nDos < nUnix )
 144       return GREATER_OF(Unix, Mac);
 145     else {
 146       // nDos == nUnix
 147       return nMac > nDos ? Type_Mac : typeDefault;
 148     }
 149
 150     #undef    GREATER_OF
 151   }
 152
 153   return typeDefault;
 154 }
 155
 156 bool wxTextFile::Read()
 157 {
 158   // file should be opened and we must be in it's beginning
 159   wxASSERT( m_file.IsOpened() && m_file.Tell() == 0 );
 160
 161   wxString str;
 162   char ch, chLast = '\0';
 163   char buf[1024];
 164   int n, nRead;
 165   while ( !m_file.Eof() ) {
 166     nRead = m_file.Read(buf, WXSIZEOF(buf));
 167     if ( nRead == wxInvalidOffset ) {
 168       // read error (error message already given in wxFile::Read)
 169       m_file.Close();
 170       return FALSE;
 171     }
 172
 173     #ifdef  __MAC__
 174       #pragma message("wxTextFile::Read() hasn't been tested with Mac files.")
 175     #endif
 176
 177     for ( n = 0; n < nRead; n++ ) {
 178       ch = buf[n];
 179       switch ( ch ) {
 180         case '\n':
 181           // Dos/Unix line termination
 182           m_aLines.Add(str);
 183           m_aTypes.Add(chLast == '\r' ? Type_Dos : Type_Unix);
 184           str.Empty();
 185           chLast = '\n';
 186           break;
 187
 188         case '\r':
 189           if ( chLast == '\r' ) {
 190             // Mac empty line
 191             m_aLines.Add("");
 192             m_aTypes.Add(Type_Mac);
 193           }
 194           else
 195             chLast = '\r';
 196           break;
 197
 198         default:
 199           if ( chLast == '\r' ) {
 200             // Mac line termination
 201             m_aLines.Add(str);
 202             m_aTypes.Add(Type_Mac);
 203             str = ch;
 204           }
 205           else {
 206             // add to the current line
 207             str += ch;
 208           }
 209       }
 210     }
 211   }
 212
 213   // anything in the last line?
 214   if ( !str.IsEmpty() ) {
 215     m_aTypes.Add(Type_None);  // no line terminator
 216     m_aLines.Add(str);
 217   }
 218
 219   return TRUE;
 220 }
 221
 222 bool wxTextFile::Write(Type typeNew)
 223 {
 224   wxTempFile fileTmp(m_strFile);
 225
 226   if ( !fileTmp.IsOpened() ) {
 227     wxLogError("can't write file '%s' to disk.", m_strFile.c_str());
 228     return FALSE;
 229   }
 230
 231   uint nCount = m_aLines.Count();
 232   for ( uint n = 0; n < nCount; n++ ) {
 233     fileTmp.Write(m_aLines[n] +
 234                   GetEOL(typeNew == Type_None ? m_aTypes[n] : typeNew));
 235   }
 236
 237   // replace the old file with this one
 238   return fileTmp.Commit();
 239 }