OleStr.h

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/*  OleStr.h - OLESTR wrapper
    Copyright (C) 2001-2004 Mark Weaver
    Written by Mark Weaver <mark@npsl.co.uk>

    Part of the Open-Win32 library.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the
    Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA  02111-1307, USA.
*/

#ifndef OW32_OleStr_h
#define OW32_OleStr_h

namespace OW32
{

class OW32_LIB_EXPORT COleStr
{
private:
    LPOLESTR m_data;

    // copy wchar_t*
    void _Copy(LPCWSTR str)
    {
        ::CoTaskMemFree(m_data);
        int size = (wcslen(str)+1)*sizeof(OLECHAR);
        m_data = (LPOLESTR)::CoTaskMemAlloc(size);
        memcpy(m_data, str, size);
    }

    // copy char*
    void _Copy(LPCSTR str)
    {
        USES_CONVERSION;
        _Copy(A2CW(str));
    }

public:
    COleStr() : m_data(0) { }

    COleStr(LPCWSTR str) : m_data(0) { _Copy(str); }
    COleStr(LPCSTR str) : m_data(0) { _Copy(str); }
    COleStr(const COleStr &str) : m_data(0) { _Copy(str.m_data); }

    ~COleStr() { ::CoTaskMemFree(m_data); }

    unsigned int Length() const { return m_data ? wcslen(m_data) : 0; }
    
    void Attach(LPOLESTR lpOle) 
    { 
        if (m_data) ::CoTaskMemFree(m_data);
        m_data = lpOle; 
    }

    LPOLESTR Detach() 
    { 
        LPOLESTR data = m_data; 
        m_data = NULL; 
        return data; 
    }

    LPOLESTR Copy() const
    {
        LPOLESTR data;
        int size = (wcslen(m_data)+1)*sizeof(OLECHAR);
        data = (LPOLESTR)::CoTaskMemAlloc(size);
        if (data)
        {
            memcpy(data, m_data, size);
        }
        return data;
    }

    COleStr& operator=(const COleStr &str)
    {
        _Copy(str.m_data);
        return *this;
    }
    
    COleStr& operator=(const LPCWSTR &str)
    {
        _Copy(str);
        return *this;
    }

    COleStr& operator=(const LPCSTR &str)
    {
        _Copy(str);
        return *this;
    }

    LPOLESTR* operator&()
    {
        _ASSERT(!m_data);
        return &m_data;
    }

    operator LPOLESTR() const { return m_data; }

    bool operator!() const { return m_data == NULL; }
    operator bool() const { return m_data != NULL; }
};

} // namespace OW32

#endif // OW32_OleStr_h

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