added wxStringStream classes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29223 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/sstream.cpp

@@ -0,0 +1,117 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        common/sstream.cpp
+// Purpose:     string-based streams implementation
+// Author:      Vadim Zeitlin
+// Modified by:
+// Created:     2004-09-19
+// RCS-ID:      $Id$
+// Copyright:   (c) 2004 Vadim Zeitlin <vadim@wxwindows.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#if wxUSE_STREAMS
+
+#include "wx/sstream.h"
+
+// ============================================================================
+// wxStringInputStream implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// seek/tell
+// ----------------------------------------------------------------------------
+
+off_t wxStringInputStream::OnSysSeek(off_t ofs, wxSeekMode mode)
+{
+    switch ( mode )
+    {
+        case wxFromStart:
+            // nothing to do, ofs already ok
+            break;
+
+        case wxFromEnd:
+            ofs += m_str.length()*sizeof(wxChar);
+            break;
+
+        case wxFromCurrent:
+            ofs += m_pos;
+            break;
+
+        default:
+            wxFAIL_MSG( _T("invalid seek mode") );
+            return wxInvalidOffset;
+    }
+
+    m_pos = wx_static_cast(size_t, ofs);
+
+    return ofs;
+}
+
+off_t wxStringInputStream::OnSysTell() const
+{
+    return wx_static_cast(off_t, m_pos);
+}
+
+// ----------------------------------------------------------------------------
+// actual IO
+// ----------------------------------------------------------------------------
+
+size_t wxStringInputStream::OnSysRead(void *buffer, size_t size)
+{
+    const size_t sizeMax = m_str.length()*sizeof(wxChar) - m_pos;
+
+    if ( size >= sizeMax )
+    {
+        if ( sizeMax == 0 )
+        {
+            m_lasterror = wxSTREAM_EOF;
+            return 0;
+        }
+
+        size = sizeMax;
+    }
+
+    memcpy(buffer, m_str.data() + m_pos, size);
+    m_pos += size;
+
+    return size;
+}
+
+// ============================================================================
+// wxStringOutputStream implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// actual IO
+// ----------------------------------------------------------------------------
+
+size_t wxStringOutputStream::OnSysWrite(const void *buffer, size_t size)
+{
+    // in Unicode mode we might not be able to write the last byte
+    size_t len = size / sizeof(wxChar);
+
+    const wxChar *p = wx_static_cast(const wxChar *, buffer);
+
+    m_str->Append(wxString(p, p + len + 1));
+
+    // return number of bytes actually written
+    return len*sizeof(wxChar);
+}
+
+#endif // wxUSE_STREAMS
+