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Diffstat (limited to 'include/systools/win32/comtools.hxx')
| -rw-r--r-- | include/systools/win32/comtools.hxx | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/include/systools/win32/comtools.hxx b/include/systools/win32/comtools.hxx new file mode 100644 index 000000000..b14184288 --- /dev/null +++ b/include/systools/win32/comtools.hxx @@ -0,0 +1,249 @@ +/* -*- 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 . + */ + +#pragma once + +#include <string> +#include <string_view> +#include <stdexcept> +#include <type_traits> +#include <utility> + +#include <prewin.h> +#include <objbase.h> +#include <postwin.h> + +namespace sal::systools +{ + /* 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_; + }; + + /* Convert failed HRESULT to thrown ComError */ + inline void ThrowIfFailed(HRESULT hr, std::string_view msg) + { + if (FAILED(hr)) + throw ComError(std::string(msg), hr); + } + + /* A guard class to call CoInitializeEx/CoUninitialize in proper pairs + * See also: o3tl::safeCoInitializeEx doing dangerous re-initialization + */ + class CoInitializeGuard + { + public: + enum class WhenFailed + { + NoThrow, // do not throw + Throw, // throw on failure + Abort, // std::abort on failure + }; + explicit CoInitializeGuard(DWORD dwCoInit, bool failChangeMode = false, + WhenFailed whenFailed = WhenFailed::Throw) + { + HRESULT hr = ::CoInitializeEx(nullptr, dwCoInit); + if (whenFailed != WhenFailed::NoThrow && FAILED(hr) + && (failChangeMode || hr != RPC_E_CHANGED_MODE)) + { + if (whenFailed == WhenFailed::Throw) + throw ComError("CoInitializeEx failed", hr); + else // if (whenFailed == Abort) + std::abort(); + } + mbUninit = SUCCEEDED(hr); + } + CoInitializeGuard(const CoInitializeGuard&) = delete; // non-construction-copyable + void operator=(const CoInitializeGuard&) = delete; // non-copyable + ~CoInitializeGuard() + { + if (mbUninit) + ::CoUninitialize(); + } + + private: + bool mbUninit; + }; + + 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: + /* Explicitly controllable whether AddRef will be called or not */ + COMReference(T* comptr = nullptr, bool bAddRef = true) : + com_ptr_(comptr) + { + if (bAddRef) + addRef(com_ptr_); + } + + COMReference(const COMReference<T>& other) : + COMReference(other.com_ptr_) + { + } + + COMReference(COMReference<T>&& other) : + COMReference(std::exchange(other.com_ptr_, nullptr), false) + { + } + + // 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.template QueryInterface<T>(t)) + { + } + + // Using CoCreateInstance + COMReference(REFCLSID clsid, IUnknown* pOuter = nullptr, DWORD nCtx = CLSCTX_ALL) + : com_ptr_(nullptr) + { + ThrowIfFailed(CoCreateInstance(clsid, pOuter, nCtx), "CoCreateInstance failed"); + } + + COMReference<T>& operator=(const COMReference<T>& other) + { + return operator=(other.com_ptr_); + } + + COMReference<T>& operator=(COMReference<T>&& other) + { + if (com_ptr_ != other.com_ptr_) + { + clear(); + std::swap(com_ptr_, other.com_ptr_); + } + return *this; + } + + COMReference<T>& operator=(T* comptr) + { + assign(comptr); + return *this; + } + + ~COMReference() { release(com_ptr_); } + + template <typename T2, typename TAG, std::enable_if_t<is_COM_query_tag<TAG>, int> = 0> + COMReference<T2> QueryInterface(TAG) const + { + T2* ip = nullptr; + HRESULT hr = E_POINTER; + if (com_ptr_) + hr = com_ptr_->QueryInterface(&ip); + + if constexpr (std::is_same_v<TAG, COM_QUERY_THROW_TAG>) + ThrowIfFailed(hr, "QueryInterface failed"); + + return { ip, false }; + } + + template <typename T2, typename TAG> + COMReference<T>& set(const COMReference<T2>& p, TAG t) + { + return operator=(p.template QueryInterface<T>(t)); + } + + HRESULT CoCreateInstance(REFCLSID clsid, IUnknown* pOuter = nullptr, + DWORD nCtx = CLSCTX_ALL) + { + T* ip; + HRESULT hr = ::CoCreateInstance(clsid, pOuter, nCtx, IID_PPV_ARGS(&ip)); + if (SUCCEEDED(hr)) + release(std::exchange(com_ptr_, ip)); + return hr; + } + + HRESULT CoGetClassObject(REFCLSID clsid, DWORD nCtx = CLSCTX_ALL) + { + T* ip; + HRESULT hr = ::CoGetClassObject(clsid, nCtx, nullptr, IID_PPV_ARGS(&ip)); + if (SUCCEEDED(hr)) + release(std::exchange(com_ptr_, ip)); + return hr; + } + + 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&() + { + clear(); + return &com_ptr_; + } + + T* get() const { return com_ptr_; } + operator T* () const { return get(); } + + void clear() { assign(nullptr); } + + bool is() const { return (com_ptr_ != nullptr); } + operator bool() const { return is(); } + + private: + static void addRef(T* ptr) + { + if (ptr) + ptr->AddRef(); + } + + static void release(T* ptr) + { + if (ptr) + ptr->Release(); + } + + void assign(T* ptr) + { + if (com_ptr_ == ptr) + return; + addRef(ptr); + release(std::exchange(com_ptr_, ptr)); + } + + T* com_ptr_; + }; + +} // sal::systools + +/* Typedefs for some popular COM interfaces */ +typedef sal::systools::COMReference<IDataObject> IDataObjectPtr; +typedef sal::systools::COMReference<IStream> IStreamPtr; + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |