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Diffstat (limited to 'src/plugins/platforms/windows/qwindowscombase.h')
-rw-r--r-- | src/plugins/platforms/windows/qwindowscombase.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/src/plugins/platforms/windows/qwindowscombase.h b/src/plugins/platforms/windows/qwindowscombase.h new file mode 100644 index 0000000000..5e51b6b7b7 --- /dev/null +++ b/src/plugins/platforms/windows/qwindowscombase.h @@ -0,0 +1,112 @@ +/**************************************************************************** +** +** Copyright (C) 2017 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the plugins of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QWINDOWSCOMBASE_H +#define QWINDOWSCOMBASE_H + +#include <QtCore/QtGlobal> + +#include <unknwn.h> + +QT_BEGIN_NAMESPACE + +// The __uuidof operator of MinGW does not work for all interfaces (for example, +// IAccessible2). Specializations of this function can be provides to work +// around this. +template <class DesiredInterface> +static IID qUuidOf() { return __uuidof(DesiredInterface); } + +// Helper for implementing IUnknown::QueryInterface. +template <class DesiredInterface, class Derived> +bool qWindowsComQueryInterface(Derived *d, REFIID id, LPVOID *iface) +{ + if (id == qUuidOf<DesiredInterface>()) { + *iface = static_cast<DesiredInterface *>(d); + d->AddRef(); + return true; + } + return false; +} + +// Helper for implementing IUnknown::QueryInterface for IUnknown +// in the case of multiple inheritance via the first inherited class. +template <class FirstInheritedInterface, class Derived> +bool qWindowsComQueryUnknownInterfaceMulti(Derived *d, REFIID id, LPVOID *iface) +{ + if (id == __uuidof(IUnknown)) { + *iface = static_cast<FirstInheritedInterface *>(d); + d->AddRef(); + return true; + } + return false; +} + +// Helper base class to provide IUnknown methods for COM classes (single inheritance) +template <class ComInterface> class QWindowsComBase : public ComInterface +{ + Q_DISABLE_COPY(QWindowsComBase) +public: + explicit QWindowsComBase(ULONG initialRefCount = 1) : m_ref(initialRefCount) {} + virtual ~QWindowsComBase() {} + + HRESULT STDMETHODCALLTYPE QueryInterface(REFIID id, LPVOID *iface) + { + *iface = nullptr; + return qWindowsComQueryInterface<IUnknown>(this, id, iface) || qWindowsComQueryInterface<ComInterface>(this, id, iface) + ? S_OK : E_NOINTERFACE; + } + + ULONG STDMETHODCALLTYPE AddRef() { return ++m_ref; } + + ULONG STDMETHODCALLTYPE Release() + { + if (!--m_ref) { + delete this; + return 0; + } + return m_ref; + } + +private: + ULONG m_ref; +}; + +QT_END_NAMESPACE + +#endif // QWINDOWSCOMBASE_H |