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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#ifndef INCLUDED_SYSTOOLS_WIN32_COMTOOLS_HXX
#define INCLUDED_SYSTOOLS_WIN32_COMTOOLS_HXX
#include <string>
#include <stdexcept>
#include <type_traits>
#include <objbase.h>
namespace sal
{
namespace systools
{
typedef int HRESULT;
/* Simple exception class for propagating COM errors */
class ComError : public std::runtime_error
{
public:
ComError(const std::string& message, HRESULT hr) :
std::runtime_error(message),
hr_(hr)
{}
HRESULT GetHresult() const
{
return hr_;
}
private:
HRESULT hr_;
};
struct COM_QUERY_TAG {} constexpr COM_QUERY;
struct COM_QUERY_THROW_TAG {} constexpr COM_QUERY_THROW;
template <typename TAG>
constexpr bool is_COM_query_tag
= std::is_same_v<TAG, COM_QUERY_TAG> || std::is_same_v<TAG, COM_QUERY_THROW_TAG>;
/* A simple COM smart pointer template */
template <typename T>
class COMReference
{
public:
COMReference() :
com_ptr_(NULL)
{
}
explicit COMReference(T* comptr) :
com_ptr_(comptr)
{
addRef();
}
// Query from IUnknown*, using COM_QUERY or COM_QUERY_THROW tags
template <typename T2, typename TAG>
COMReference(const COMReference<T2>& p, TAG t)
: COMReference(p.QueryInterface<T>(t))
{
}
/* Explicitly controllable whether AddRef will be called or not */
COMReference(T* comptr, bool bAddRef) :
com_ptr_(comptr)
{
if (bAddRef)
addRef();
}
COMReference(const COMReference<T>& other) :
com_ptr_(other.com_ptr_)
{
addRef();
}
COMReference<T>& operator=(const COMReference<T>& other)
{
if (other.com_ptr_)
other.com_ptr_->AddRef();
release();
com_ptr_ = other.com_ptr_;
return *this;
}
COMReference<T>& operator=(T* comptr)
{
release();
com_ptr_ = comptr;
addRef();
return *this;
}
~COMReference()
{
release();
}
template <typename T2, typename TAG, std::enable_if_t<is_COM_query_tag<TAG>, int> = 0>
COMReference<T2> QueryInterface(TAG) const
{
void* ip = nullptr;
HRESULT hr = E_FAIL;
if (com_ptr_)
hr = com_ptr_->QueryInterface(__uuidof(T2), &ip);
if constexpr (std::is_same_v<TAG, COM_QUERY_THROW_TAG>)
if (FAILED(hr))
throw ComError("QueryInterface failed: Interface not supported!", hr);
return { static_cast<T2*>(ip), false };
}
COMReference<T>& CoCreateInstance(REFCLSID clsid, IUnknown* pOuter = nullptr,
DWORD nCtx = CLSCTX_ALL)
{
clear();
HRESULT hr = ::CoCreateInstance(clsid, pOuter, nCtx, __uuidof(T),
reinterpret_cast<void**>(&com_ptr_));
if (FAILED(hr))
throw ComError("CoCreateInstance failed!", hr);
return *this;
}
T* operator->() const
{
return com_ptr_;
}
T& operator*() const
{
return *com_ptr_;
}
/* Necessary for assigning com_ptr_ from functions like
CoCreateInstance which require a 'void**' */
T** operator&()
{
release();
com_ptr_ = NULL;
return &com_ptr_;
}
T* get() const
{
return com_ptr_;
}
void clear()
{
release();
com_ptr_ = NULL;
}
bool is() const
{
return (com_ptr_ != NULL);
}
private:
ULONG addRef()
{
ULONG cnt = 0;
if (com_ptr_)
cnt = com_ptr_->AddRef();
return cnt;
}
ULONG release()
{
ULONG cnt = 0;
if (com_ptr_)
cnt = com_ptr_->Release();
return cnt;
}
private:
T* com_ptr_;
};
} // systools
} // sal
/* Typedefs for some popular COM interfaces */
typedef sal::systools::COMReference<IDataObject> IDataObjectPtr;
typedef sal::systools::COMReference<IStream> IStreamPtr;
#endif // INCLUDED_SYSTOOLS_WIN32_COMTOOLS_HXX
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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