src/common/stdstream.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/stdstream.h
   3 // Purpose:     Implementation of std::istream and std::ostream derived
   4 //              wrappers for wxInputStream and wxOutputStream
   5 // Author:      Jonathan Liu <net147@gmail.com>
   6 // Created:     2009-05-02
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2009 Jonathan Liu
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ==========================================================================
  13 // Declarations
  14 // ==========================================================================
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20     #pragma hdrstop
  21 #endif
  22
  23 #if wxUSE_STD_IOSTREAM
  24
  25 #ifndef WX_PRECOMP
  26 #endif
  27
  28 #include "wx/stdstream.h"
  29
  30 #include <ios>
  31 #include <istream>
  32 #include <ostream>
  33 #include <streambuf>
  34
  35 // ==========================================================================
  36 // Helpers
  37 // ==========================================================================
  38
  39 namespace
  40 {
  41
  42 bool
  43 IosSeekDirToWxSeekMode(std::ios_base::seekdir way,
  44                        wxSeekMode& seekMode)
  45 {
  46     switch ( way )
  47     {
  48         case std::ios_base::beg:
  49             seekMode = wxFromStart;
  50             break;
  51         case std::ios_base::cur:
  52             seekMode = wxFromCurrent;
  53             break;
  54         case std::ios_base::end:
  55             seekMode = wxFromEnd;
  56             break;
  57         default:
  58             return false;
  59     }
  60
  61     return true;
  62 }
  63
  64 } // anonymous namespace
  65
  66 // ==========================================================================
  67 // wxStdInputStreamBuffer
  68 // ==========================================================================
  69
  70 wxStdInputStreamBuffer::wxStdInputStreamBuffer(wxInputStream& stream) :
  71     m_stream(stream), m_lastChar(EOF)
  72 {
  73 }
  74
  75 std::streambuf *
  76 wxStdInputStreamBuffer::setbuf(char *WXUNUSED(s),
  77                                std::streamsize WXUNUSED(n))
  78 {
  79     return NULL;
  80 }
  81
  82 std::streampos
  83 wxStdInputStreamBuffer::seekoff(std::streamoff off,
  84                                 std::ios_base::seekdir way,
  85                                 std::ios_base::openmode which)
  86 {
  87     wxSeekMode seekMode;
  88
  89     if ( !IosSeekDirToWxSeekMode(way, seekMode) )
  90         return -1;
  91     if ( !(which & std::ios_base::in) )
  92         return -1;
  93
  94     off_t newPos = m_stream.SeekI((off_t) off, seekMode);
  95
  96     if ( newPos != wxInvalidOffset )
  97         return (std::streampos) newPos;
  98     else
  99         return -1;
 100 }
 101
 102 std::streampos
 103 wxStdInputStreamBuffer::seekpos(std::streampos sp,
 104                                 std::ios_base::openmode which)
 105 {
 106     if ( !(which & std::ios_base::in) )
 107         return -1;
 108
 109     off_t newPos = m_stream.SeekI((off_t) sp);
 110
 111     if ( newPos != wxInvalidOffset )
 112         return (std::streampos) newPos;
 113     else
 114         return -1;
 115 }
 116
 117 std::streamsize
 118 wxStdInputStreamBuffer::showmanyc()
 119 {
 120     if ( m_stream.CanRead() && (off_t) m_stream.GetSize() > m_stream.TellI() )
 121         return m_stream.GetSize() - m_stream.TellI();
 122     else
 123         return 0;
 124 }
 125
 126 std::streamsize
 127 wxStdInputStreamBuffer::xsgetn(char *s, std::streamsize n)
 128 {
 129     m_stream.Read((void *) s, (size_t) n);
 130
 131     std::streamsize read = m_stream.LastRead();
 132
 133     if ( read > 0 )
 134         m_lastChar = (unsigned char) s[read - 1];
 135
 136     return read;
 137 }
 138
 139 int
 140 wxStdInputStreamBuffer::underflow()
 141 {
 142     int ch = m_stream.GetC();
 143
 144     if ( m_stream.LastRead() == 1 )
 145     {
 146         m_stream.Ungetch((char) ch);
 147         return ch;
 148     }
 149     else
 150     {
 151         return EOF;
 152     }
 153 }
 154
 155 int
 156 wxStdInputStreamBuffer::uflow()
 157 {
 158     int ch = m_stream.GetC();
 159
 160     if ( m_stream.LastRead() == 1 )
 161     {
 162         m_lastChar = ch;
 163         return ch;
 164     }
 165     else
 166     {
 167         return EOF;
 168     }
 169 }
 170
 171 int
 172 wxStdInputStreamBuffer::pbackfail(int c)
 173 {
 174     if ( c == EOF )
 175     {
 176         if ( m_lastChar == EOF )
 177             return EOF;
 178
 179         c = m_lastChar;
 180         m_lastChar = EOF;
 181     }
 182
 183     return m_stream.Ungetch((char) c) ? c : EOF;
 184 }
 185
 186 // ==========================================================================
 187 // wxStdOutputStreamBuffer
 188 // ==========================================================================
 189
 190 wxStdOutputStreamBuffer::wxStdOutputStreamBuffer(wxOutputStream& stream) :
 191     m_stream(stream)
 192 {
 193 }
 194
 195 std::streambuf *
 196 wxStdOutputStreamBuffer::setbuf(char *WXUNUSED(s),
 197                                 std::streamsize WXUNUSED(n))
 198 {
 199     return NULL;
 200 }
 201
 202 std::streampos
 203 wxStdOutputStreamBuffer::seekoff(std::streamoff off,
 204                                  std::ios_base::seekdir way,
 205                                  std::ios_base::openmode which)
 206 {
 207     wxSeekMode seekMode;
 208
 209     if ( !IosSeekDirToWxSeekMode(way, seekMode) )
 210         return -1;
 211     if ( !(which & std::ios_base::out) )
 212         return -1;
 213
 214     off_t newPos = m_stream.SeekO((off_t) off, seekMode);
 215
 216     if ( newPos != wxInvalidOffset )
 217         return (std::streampos) newPos;
 218     else
 219         return -1;
 220 }
 221
 222 std::streampos
 223 wxStdOutputStreamBuffer::seekpos(std::streampos sp,
 224                                  std::ios_base::openmode which)
 225 {
 226     if ( !(which & std::ios_base::out) )
 227         return -1;
 228
 229     off_t newPos = m_stream.SeekO((off_t) sp);
 230
 231     if ( newPos != wxInvalidOffset )
 232         return (std::streampos) newPos;
 233     else
 234         return -1;
 235 }
 236
 237 std::streamsize
 238 wxStdOutputStreamBuffer::xsputn(const char *s,
 239                                 std::streamsize n)
 240 {
 241     m_stream.Write((const void *) s, (size_t) n);
 242     return (std::streamsize) m_stream.LastWrite();
 243 }
 244
 245 int
 246 wxStdOutputStreamBuffer::overflow(int c)
 247 {
 248     m_stream.PutC(c);
 249     return m_stream.IsOk() ? c : EOF;
 250 }
 251
 252 // ==========================================================================
 253 // wxStdInputStream and wxStdOutputStream
 254 // ==========================================================================
 255
 256 // FIXME-VC6: it is impossible to call basic_ios<char>::init() with this
 257 //            compiler, it complains about invalid call to non-static member
 258 //            function so use a suspicious (as it uses a pointer to not yet
 259 //            constructed streambuf) but working workaround
 260 //
 261 //            It also doesn't like using istream in the ctor initializer list
 262 //            and we must spell it out as basic_istream<char>.
 263 #ifdef __VISUALC6__
 264
 265 wxStdInputStream::wxStdInputStream(wxInputStream& stream)
 266     : std::basic_istream<char, std::char_traits<char> >(&m_streamBuffer),
 267       m_streamBuffer(stream)
 268 {
 269 }
 270
 271 wxStdOutputStream::wxStdOutputStream(wxOutputStream& stream)
 272     : std::basic_ostream<char, std::char_traits<char> >(&m_streamBuffer),
 273       m_streamBuffer(stream)
 274 {
 275 }
 276
 277 #else // !VC6
 278
 279 wxStdInputStream::wxStdInputStream(wxInputStream& stream) :
 280     std::istream(NULL), m_streamBuffer(stream)
 281 {
 282     std::ios::init(&m_streamBuffer);
 283 }
 284
 285 wxStdOutputStream::wxStdOutputStream(wxOutputStream& stream) :
 286     std::ostream(NULL), m_streamBuffer(stream)
 287 {
 288     std::ios::init(&m_streamBuffer);
 289 }
 290
 291 #endif // VC6/!VC6
 292
 293 #endif // wxUSE_STD_IOSTREAM