src/common/stdstream.cpp

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