added wxStringStream classes

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

include/wx/sstream.h

@@ -0,0 +1,89 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/sstream.h
+// Purpose:     string-based streams
+// Author:      Vadim Zeitlin
+// Modified by:
+// Created:     2004-09-19
+// RCS-ID:      $Id$
+// Copyright:   (c) 2004 Vadim Zeitlin <vadim@wxwindows.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_SSTREAM_H_
+#define _WX_SSTREAM_H_
+
+#include "wx/stream.h"
+
+#if wxUSE_STREAMS
+
+// ----------------------------------------------------------------------------
+// wxStringInputStream is a stream reading from the given (fixed size) string
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxStringInputStream : public wxInputStream
+{
+public:
+    // ctor associates the stream with the given string which makes a copy of
+    // it
+    wxStringInputStream(const wxString& s)
+        : m_str(s)
+    {
+        m_pos = 0;
+    }
+
+protected:
+    virtual size_t GetSize() const { return m_str.length(); }
+    virtual off_t OnSysSeek(off_t ofs, wxSeekMode mode);
+    virtual off_t OnSysTell() const;
+    virtual size_t OnSysRead(void *buffer, size_t size);
+
+private:
+    // the string we're reading from
+    wxString m_str;
+
+    // position in the stream in bytes, *not* in chars
+    size_t m_pos;
+
+
+    DECLARE_NO_COPY_CLASS(wxStringInputStream)
+};
+
+// ----------------------------------------------------------------------------
+// wxStringOutputStream writes data to the given string, expanding it as needed
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxStringOutputStream : public wxOutputStream
+{
+public:
+    // The stream will write data either to the provided string or to an
+    // internal string which can be retrieved using GetString()
+    wxStringOutputStream(wxString *pString = NULL)
+    {
+        m_str = pString ? pString : &m_strInternal;
+        m_pos = m_str->length() / sizeof(wxChar);
+    }
+
+    // get the string containing current output
+    const wxString& GetString() const { return *m_str; }
+
+protected:
+    virtual size_t OnSysWrite(const void *buffer, size_t size);
+
+private:
+    // internal string, not used if caller provided his own string
+    wxString m_strInternal;
+
+    // pointer given by the caller or just pointer to m_strInternal
+    wxString *m_str;
+
+    // position in the stream in bytes, *not* in chars
+    size_t m_pos;
+
+
+    DECLARE_NO_COPY_CLASS(wxStringOutputStream)
+};
+
+#endif // wxUSE_STREAMS
+
+#endif // _WX_SSTREAM_H_
+