include/comphelper/servicehelper.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_COMPHELPER_SERVICEHELPER_HXX
  21 #define INCLUDED_COMPHELPER_SERVICEHELPER_HXX
  22
  23 #include <rtl/uuid.h>
  24 #include <com/sun/star/lang/XUnoTunnel.hpp>
  25 #include <com/sun/star/uno/Sequence.hxx>
  26
  27 namespace comphelper {
  28
  29     // Class incapsulating UIDs used as e.g. tunnel IDs for css::lang::XUnoTunnel,
  30     // or implementation IDs for css::lang::XTypeProvider
  31     class UnoIdInit
  32     {
  33     private:
  34         css::uno::Sequence< sal_Int8 > m_aSeq;
  35     public:
  36         UnoIdInit() : m_aSeq(16)
  37         {
  38             rtl_createUuid(reinterpret_cast<sal_uInt8*>(m_aSeq.getArray()), nullptr, true);
  39         }
  40         const css::uno::Sequence< sal_Int8 >& getSeq() const { return m_aSeq; }
  41     };
  42
  43     inline sal_Int64 getSomething_cast(void* p)
  44     {
  45         return sal::static_int_cast<sal_Int64>(reinterpret_cast<sal_IntPtr>(p));
  46     }
  47
  48     template<class T> inline T* getSomething_cast(sal_Int64 n)
  49     {
  50         return reinterpret_cast<T*>(sal::static_int_cast<sal_IntPtr>(n));
  51     }
  52
  53     template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::lang::XUnoTunnel>& xUT)
  54     {
  55         if (!xUT.is())
  56             return nullptr;
  57
  58         return getSomething_cast<T>(xUT->getSomething(T::getUnoTunnelId()));
  59     }
  60
  61     // Takes an interface
  62     template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::uno::XInterface>& xIface)
  63     {
  64         return getFromUnoTunnel<T>(
  65             css::uno::Reference<css::lang::XUnoTunnel>{ xIface, css::uno::UNO_QUERY });
  66     }
  67
  68     template <typename T>
  69     inline bool isUnoTunnelId(const css::uno::Sequence< sal_Int8 >& rId)
  70     {
  71         return rId.getLength() == 16
  72             && memcmp(T::getUnoTunnelId().getConstArray(), rId.getConstArray(), 16) == 0;
  73     }
  74
  75     template <class Base> struct FallbackToGetSomethingOf
  76     {
  77         static sal_Int64 get(const css::uno::Sequence<sal_Int8>& rId, Base* p)
  78         {
  79             return p->Base::getSomething(rId);
  80         }
  81     };
  82
  83     template <> struct FallbackToGetSomethingOf<void>
  84     {
  85         static sal_Int64 get(const css::uno::Sequence<sal_Int8>&, void*) { return 0; }
  86     };
  87
  88     template <class T, class Base = void>
  89     sal_Int64 getSomethingImpl(const css::uno::Sequence<sal_Int8>& rId, T* pThis,
  90         FallbackToGetSomethingOf<Base> = {})
  91     {
  92         if (isUnoTunnelId<T>(rId))
  93             return getSomething_cast(pThis);
  94
  95         return FallbackToGetSomethingOf<Base>::get(rId, pThis);
  96     }
  97
  98 }
  99
 100 /** the UNO3_GETIMPLEMENTATION_* macros  implement a static helper function
 101     that gives access to your implementation for a given interface reference,
 102     if possible.
 103
 104     Example:
 105         MyClass* pClass = comphelper::getFromUnoTunnel<MyClass>( xRef );
 106
 107     Usage:
 108         Put a UNO3_GETIMPLEMENTATION_DECL( classname ) inside your class
 109         definition and UNO3_GETIMPLEMENTATION_IMPL( classname ) inside
 110         your cxx file. Your class must inherit css::lang::XUnoTunnel
 111         and export it with queryInterface. Implementation of XUnoTunnel is
 112         done by this macro.
 113 */
 114 #define UNO3_GETIMPLEMENTATION_DECL( classname ) \
 115     static const css::uno::Sequence< sal_Int8 > & getUnoTunnelId() noexcept; \
 116     virtual sal_Int64 SAL_CALL getSomething( const css::uno::Sequence< sal_Int8 >& aIdentifier ) override;
 117
 118 #define UNO3_GETIMPLEMENTATION_BASE_IMPL( classname ) \
 119 const css::uno::Sequence< sal_Int8 > & classname::getUnoTunnelId() noexcept \
 120 { \
 121     static const comphelper::UnoIdInit aId; \
 122     return aId.getSeq(); \
 123 }
 124
 125 #define UNO3_GETIMPLEMENTATION_IMPL( classname )\
 126 UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
 127 sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
 128 { \
 129     return comphelper::getSomethingImpl(rId, this); \
 130 }
 131
 132 #define UNO3_GETIMPLEMENTATION2_IMPL( classname, baseclass )\
 133 UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
 134 sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
 135 { \
 136     return comphelper::getSomethingImpl(rId, this, comphelper::FallbackToGetSomethingOf<baseclass>{}); \
 137 }
 138
 139
 140 #endif // INCLUDED_COMPHELPER_SERVICEHELPER_HXX
 141
 142 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */