added wxStd{In,Out}putStream classes (closes #10637)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60483 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/stdstream.cpp

@@ -0,0 +1,272 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/stdstream.h
+// Purpose:     Implementation of std::istream and std::ostream derived
+//              wrappers for wxInputStream and wxOutputStream
+// Author:      Jonathan Liu <net147@gmail.com>
+// Created:     2009-05-02
+// RCS-ID:      $Id$
+// Copyright:   (c) 2009 Jonathan Liu
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+// ==========================================================================
+// Declarations
+// ==========================================================================
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#if wxUSE_STD_IOSTREAM
+
+#ifndef WX_PRECOMP
+#endif
+
+#include "wx/stdstream.h"
+
+#include <ios>
+#include <istream>
+#include <ostream>
+#include <streambuf>
+
+// ==========================================================================
+// Helpers
+// ==========================================================================
+
+namespace
+{
+
+inline bool
+IosSeekDirToWxSeekMode(std::ios_base::seekdir way,
+                       wxSeekMode& seekMode)
+{
+    switch ( way )
+    {
+        case std::ios_base::beg:
+            seekMode = wxFromStart;
+            break;
+        case std::ios_base::cur:
+            seekMode = wxFromCurrent;
+            break;
+        case std::ios_base::end:
+            seekMode = wxFromEnd;
+            break;
+        default:
+            return false;
+    }
+
+    return true;
+}
+
+} // anonymous namespace
+
+// ==========================================================================
+// wxStdInputStreamBuffer
+// ==========================================================================
+
+wxStdInputStreamBuffer::wxStdInputStreamBuffer(wxInputStream& stream) :
+    m_stream(stream), m_lastChar(EOF)
+{
+}
+
+std::streambuf *
+wxStdInputStreamBuffer::setbuf(char *WXUNUSED(s),
+                               std::streamsize WXUNUSED(n))
+{
+    return NULL;
+}
+
+std::streampos
+wxStdInputStreamBuffer::seekoff(std::streamoff off,
+                                std::ios_base::seekdir way,
+                                std::ios_base::openmode which)
+{
+    wxSeekMode seekMode;
+
+    if ( !IosSeekDirToWxSeekMode(way, seekMode) )
+        return -1;
+    if ( !(which & std::ios_base::in) )
+        return -1;
+
+    off_t newPos = m_stream.SeekI((off_t) off, seekMode);
+
+    if ( newPos != wxInvalidOffset )
+        return (std::streampos) newPos;
+    else
+        return -1;
+}
+
+std::streampos
+wxStdInputStreamBuffer::seekpos(std::streampos sp,
+                                std::ios_base::openmode which)
+{
+    if ( !(which & std::ios_base::in) )
+        return -1;
+
+    off_t newPos = m_stream.SeekI((off_t) sp);
+
+    if ( newPos != wxInvalidOffset )
+        return (std::streampos) newPos;
+    else
+        return -1;
+}
+
+std::streamsize
+wxStdInputStreamBuffer::showmanyc()
+{
+    if ( m_stream.CanRead() && (off_t) m_stream.GetSize() > m_stream.TellI() )
+        return m_stream.GetSize() - m_stream.TellI();
+    else
+        return 0;
+}
+
+std::streamsize
+wxStdInputStreamBuffer::xsgetn(char *s, std::streamsize n)
+{
+    m_stream.Read((void *) s, (size_t) n);
+
+    std::streamsize read = m_stream.LastRead();
+
+    if ( read > 0 )
+        m_lastChar = (unsigned char) s[read - 1];
+
+    return read;
+}
+
+int
+wxStdInputStreamBuffer::underflow()
+{
+    int ch = m_stream.GetC();
+
+    if ( m_stream.LastRead() == 1 )
+    {
+        m_stream.Ungetch((char) ch);
+        return ch;
+    }
+    else
+    {
+        return EOF;
+    }
+}
+
+int
+wxStdInputStreamBuffer::uflow()
+{
+    int ch = m_stream.GetC();
+
+    if ( m_stream.LastRead() == 1 )
+    {
+        m_lastChar = ch;
+        return ch;
+    }
+    else
+    {
+        return EOF;
+    }
+}
+
+int
+wxStdInputStreamBuffer::pbackfail(int c)
+{
+    if ( c == EOF )
+    {
+        if ( m_lastChar == EOF )
+            return EOF;
+
+        c = m_lastChar;
+        m_lastChar = EOF;
+    }
+
+    return m_stream.Ungetch((char) c) ? c : EOF;
+}
+
+// ==========================================================================
+// wxStdInputStream
+// ==========================================================================
+
+wxStdInputStream::wxStdInputStream(wxInputStream& stream) :
+    std::istream(NULL), m_streamBuffer(stream)
+{
+    std::ios::init(&m_streamBuffer);
+}
+
+// ==========================================================================
+// wxStdOutputStreamBuffer
+// ==========================================================================
+
+wxStdOutputStreamBuffer::wxStdOutputStreamBuffer(wxOutputStream& stream) :
+    m_stream(stream)
+{
+}
+
+std::streambuf *
+wxStdOutputStreamBuffer::setbuf(char *WXUNUSED(s),
+                                std::streamsize WXUNUSED(n))
+{
+    return NULL;
+}
+
+std::streampos
+wxStdOutputStreamBuffer::seekoff(std::streamoff off,
+                                 std::ios_base::seekdir way,
+                                 std::ios_base::openmode which)
+{
+    wxSeekMode seekMode;
+
+    if ( !IosSeekDirToWxSeekMode(way, seekMode) )
+        return -1;
+    if ( !(which & std::ios_base::out) )
+        return -1;
+
+    off_t newPos = m_stream.SeekO((off_t) off, seekMode);
+
+    if ( newPos != wxInvalidOffset )
+        return (std::streampos) newPos;
+    else
+        return -1;
+}
+
+std::streampos
+wxStdOutputStreamBuffer::seekpos(std::streampos sp,
+                                 std::ios_base::openmode which)
+{
+    if ( !(which & std::ios_base::out) )
+        return -1;
+
+    off_t newPos = m_stream.SeekO((off_t) sp);
+
+    if ( newPos != wxInvalidOffset )
+        return (std::streampos) newPos;
+    else
+        return -1;
+}
+
+std::streamsize
+wxStdOutputStreamBuffer::xsputn(const char *s,
+                                std::streamsize n)
+{
+    m_stream.Write((const void *) s, (size_t) n);
+    return (std::streamsize) m_stream.LastWrite();
+}
+
+int
+wxStdOutputStreamBuffer::overflow(int c)
+{
+    m_stream.PutC(c);
+    return m_stream.IsOk() ? c : EOF;
+}
+
+// ==========================================================================
+// wxStdOutputStream
+// ==========================================================================
+
+wxStdOutputStream::wxStdOutputStream(wxOutputStream& stream) :
+    std::ostream(NULL), m_streamBuffer(stream)
+{
+    std::ios::init(&m_streamBuffer);
+}
+
+#endif // wxUSE_STD_IOSTREAM