1 files changed, 152 insertions, 0 deletions
diff --git a/include/comphelper/servicehelper.hxx b/include/comphelper/servicehelper.hxx
new file mode 100644
index 000000000..c225494cc
--- /dev/null
+++ b/include/comphelper/servicehelper.hxx
@@ -0,0 +1,152 @@
+/* -*- 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_COMPHELPER_SERVICEHELPER_HXX
+#define INCLUDED_COMPHELPER_SERVICEHELPER_HXX
+
+#include <rtl/uuid.h>
+#include <com/sun/star/lang/XUnoTunnel.hpp>
+#include <com/sun/star/uno/Sequence.hxx>
+
+namespace comphelper {
+
+    // Class incapsulating UIDs used as e.g. tunnel IDs for css::lang::XUnoTunnel,
+    // or implementation IDs for css::lang::XTypeProvider
+    class UnoIdInit
+    {
+    private:
+        css::uno::Sequence< sal_Int8 > m_aSeq;
+    public:
+        UnoIdInit() : m_aSeq(16)
+        {
+            rtl_createUuid(reinterpret_cast<sal_uInt8*>(m_aSeq.getArray()), nullptr, true);
+        }
+        const css::uno::Sequence< sal_Int8 >& getSeq() const { return m_aSeq; }
+    };
+
+    inline sal_Int64 getSomething_cast(void* p)
+    {
+        return sal::static_int_cast<sal_Int64>(reinterpret_cast<sal_IntPtr>(p));
+    }
+
+    template<class T> inline T* getSomething_cast(sal_Int64 n)
+    {
+        return reinterpret_cast<T*>(sal::static_int_cast<sal_IntPtr>(n));
+    }
+
+    template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::lang::XUnoTunnel>& xUT)
+    {
+        if (!xUT.is())
+            return nullptr;
+
+        return getSomething_cast<T>(xUT->getSomething(T::getUnoTunnelId()));
+    }
+
+    // Takes an interface
+    template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::uno::XInterface>& xIface)
+    {
+        return getFromUnoTunnel<T>(
+            css::uno::Reference<css::lang::XUnoTunnel>{ xIface, css::uno::UNO_QUERY });
+    }
+
+    // Takes an Any
+    template <class T> T* getFromUnoTunnel(const css::uno::Any& rAny)
+    {
+        // For unclear reason, using a Reference ctor taking an Any
+        // gives different results compared to use of operator >>=.
+        css::uno::Reference<css::lang::XUnoTunnel> xUnoTunnel;
+        rAny >>= xUnoTunnel;
+        return getFromUnoTunnel<T>(xUnoTunnel);
+    }
+
+    template <typename T>
+    inline bool isUnoTunnelId(const css::uno::Sequence< sal_Int8 >& rId)
+    {
+        return rId.getLength() == 16
+            && memcmp(T::getUnoTunnelId().getConstArray(), rId.getConstArray(), 16) == 0;
+    }
+
+    template <class Base> struct FallbackToGetSomethingOf
+    {
+        static sal_Int64 get(const css::uno::Sequence<sal_Int8>& rId, Base* p)
+        {
+            return p->Base::getSomething(rId);
+        }
+    };
+
+    template <> struct FallbackToGetSomethingOf<void>
+    {
+        static sal_Int64 get(const css::uno::Sequence<sal_Int8>&, void*) { return 0; }
+    };
+
+    template <class T, class Base = void>
+    sal_Int64 getSomethingImpl(const css::uno::Sequence<sal_Int8>& rId, T* pThis,
+        FallbackToGetSomethingOf<Base> = {})
+    {
+        if (isUnoTunnelId<T>(rId))
+            return getSomething_cast(pThis);
+
+        return FallbackToGetSomethingOf<Base>::get(rId, pThis);
+    }
+
+}
+
+/** the UNO3_GETIMPLEMENTATION_* macros  implement a static helper function
+    that gives access to your implementation for a given interface reference,
+    if possible.
+
+    Example:
+        MyClass* pClass = comphelper::getFromUnoTunnel<MyClass>( xRef );
+
+    Usage:
+        Put a UNO3_GETIMPLEMENTATION_DECL( classname ) inside your class
+        definition and UNO3_GETIMPLEMENTATION_IMPL( classname ) inside
+        your cxx file. Your class must inherit css::lang::XUnoTunnel
+        and export it with queryInterface. Implementation of XUnoTunnel is
+        done by this macro.
+*/
+#define UNO3_GETIMPLEMENTATION_DECL( classname ) \
+    static const css::uno::Sequence< sal_Int8 > & getUnoTunnelId() noexcept; \
+    virtual sal_Int64 SAL_CALL getSomething( const css::uno::Sequence< sal_Int8 >& aIdentifier ) override;
+
+#define UNO3_GETIMPLEMENTATION_BASE_IMPL( classname ) \
+const css::uno::Sequence< sal_Int8 > & classname::getUnoTunnelId() noexcept \
+{ \
+    static const comphelper::UnoIdInit aId; \
+    return aId.getSeq(); \
+}
+
+#define UNO3_GETIMPLEMENTATION_IMPL( classname )\
+UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
+sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
+{ \
+    return comphelper::getSomethingImpl(rId, this); \
+}
+
+#define UNO3_GETIMPLEMENTATION2_IMPL( classname, baseclass )\
+UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
+sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
+{ \
+    return comphelper::getSomethingImpl(rId, this, comphelper::FallbackToGetSomethingOf<baseclass>{}); \
+}
+
+
+#endif // INCLUDED_COMPHELPER_SERVICEHELPER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */