src/common/sstream.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        common/sstream.cpp
   3 // Purpose:     string-based streams implementation
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     2004-09-19
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2004 Vadim Zeitlin <vadim@wxwindows.org>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_STREAMS
  28
  29 #include "wx/sstream.h"
  30
  31 // ============================================================================
  32 // wxStringInputStream implementation
  33 // ============================================================================
  34
  35 // ----------------------------------------------------------------------------
  36 // seek/tell
  37 // ----------------------------------------------------------------------------
  38
  39 wxFileOffset wxStringInputStream::OnSysSeek(wxFileOffset ofs, wxSeekMode mode)
  40 {
  41     const size_t ofsMax = m_str.length()*sizeof(wxChar);
  42
  43     switch ( mode )
  44     {
  45         case wxFromStart:
  46             // nothing to do, ofs already ok
  47             break;
  48
  49         case wxFromEnd:
  50             ofs += ofsMax;
  51             break;
  52
  53         case wxFromCurrent:
  54             ofs += m_pos;
  55             break;
  56
  57         default:
  58             wxFAIL_MSG( _T("invalid seek mode") );
  59             return wxInvalidOffset;
  60     }
  61
  62     if ( ofs < 0 || wx_static_cast(size_t, ofs) >= ofsMax )
  63         return wxInvalidOffset;
  64
  65     m_pos = wx_static_cast(size_t, ofs);
  66
  67     return ofs;
  68 }
  69
  70 wxFileOffset wxStringInputStream::OnSysTell() const
  71 {
  72     return wx_static_cast(wxFileOffset, m_pos);
  73 }
  74
  75 // ----------------------------------------------------------------------------
  76 // actual IO
  77 // ----------------------------------------------------------------------------
  78
  79 size_t wxStringInputStream::OnSysRead(void *buffer, size_t size)
  80 {
  81     const size_t sizeMax = m_str.length()*sizeof(wxChar) - m_pos;
  82
  83     if ( size >= sizeMax )
  84     {
  85         if ( sizeMax == 0 )
  86         {
  87             m_lasterror = wxSTREAM_EOF;
  88             return 0;
  89         }
  90
  91         size = sizeMax;
  92     }
  93
  94     memcpy(buffer, m_str.data() + m_pos, size);
  95     m_pos += size;
  96
  97     return size;
  98 }
  99
 100 // ============================================================================
 101 // wxStringOutputStream implementation
 102 // ============================================================================
 103
 104 // ----------------------------------------------------------------------------
 105 // seek/tell
 106 // ----------------------------------------------------------------------------
 107
 108 wxFileOffset wxStringOutputStream::OnSysTell() const
 109 {
 110     return wx_static_cast(wxFileOffset, m_pos);
 111 }
 112
 113 // ----------------------------------------------------------------------------
 114 // actual IO
 115 // ----------------------------------------------------------------------------
 116
 117 size_t wxStringOutputStream::OnSysWrite(const void *buffer, size_t size)
 118 {
 119     // in Unicode mode we might not be able to write the last byte
 120     size_t len = size / sizeof(wxChar);
 121
 122     const wxChar *p = wx_static_cast(const wxChar *, buffer);
 123
 124     m_str->Append(wxString(p, p + len));
 125
 126     // return number of bytes actually written
 127     len *= sizeof(wxChar);
 128     m_pos += len;
 129
 130     return len;
 131 }
 132
 133 #endif // wxUSE_STREAMS
 134