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 #include <type_traits>
  28
  29 namespace comphelper {
  30
  31     // Class incapsulating UIDs used as e.g. tunnel IDs for css::lang::XUnoTunnel,
  32     // or implementation IDs for css::lang::XTypeProvider
  33     class UnoIdInit
  34     {
  35     private:
  36         css::uno::Sequence< sal_Int8 > m_aSeq;
  37     public:
  38         UnoIdInit() : m_aSeq(16)
  39         {
  40             rtl_createUuid(reinterpret_cast<sal_uInt8*>(m_aSeq.getArray()), nullptr, true);
  41         }
  42         const css::uno::Sequence< sal_Int8 >& getSeq() const { return m_aSeq; }
  43     };
  44
  45     inline sal_Int64 getSomething_cast(void* p)
  46     {
  47         return sal::static_int_cast<sal_Int64>(reinterpret_cast<sal_IntPtr>(p));
  48     }
  49
  50     template<class T> inline T* getSomething_cast(sal_Int64 n)
  51     {
  52         return reinterpret_cast<T*>(sal::static_int_cast<sal_IntPtr>(n));
  53     }
  54
  55     template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::lang::XUnoTunnel>& xUT)
  56     {
  57         if (!xUT.is())
  58             return nullptr;
  59
  60         return getSomething_cast<T>(xUT->getSomething(T::getUnoTunnelId()));
  61     }
  62
  63     // Takes an interface
  64     template <class T> T* getFromUnoTunnel(const css::uno::Reference<css::uno::XInterface>& xIface)
  65     {
  66         return getFromUnoTunnel<T>(
  67             css::uno::Reference<css::lang::XUnoTunnel>{ xIface, css::uno::UNO_QUERY });
  68     }
  69
  70     // Takes an Any
  71     template <class T> T* getFromUnoTunnel(const css::uno::Any& rAny)
  72     {
  73         // For unclear reason, using a Reference ctor taking an Any
  74         // gives different results compared to use of operator >>=.
  75         css::uno::Reference<css::lang::XUnoTunnel> xUnoTunnel;
  76         rAny >>= xUnoTunnel;
  77         return getFromUnoTunnel<T>(xUnoTunnel);
  78     }
  79
  80     template <typename T>
  81     inline bool isUnoTunnelId(const css::uno::Sequence< sal_Int8 >& rId)
  82     {
  83         return rId.getLength() == 16
  84             && memcmp(T::getUnoTunnelId().getConstArray(), rId.getConstArray(), 16) == 0;
  85     }
  86
  87     template <class Base> struct FallbackToGetSomethingOf
  88     {
  89         static sal_Int64 get(const css::uno::Sequence<sal_Int8>& rId, Base* p)
  90         {
  91             return p->Base::getSomething(rId);
  92         }
  93     };
  94
  95     template <> struct FallbackToGetSomethingOf<void>
  96     {
  97         static sal_Int64 get(const css::uno::Sequence<sal_Int8>&, void*) { return 0; }
  98     };
  99
 100     template <class T, class Base = void>
 101     sal_Int64 getSomethingImpl(const css::uno::Sequence<sal_Int8>& rId, T* pThis,
 102         FallbackToGetSomethingOf<Base> = {})
 103     {
 104         if (isUnoTunnelId<T>(rId))
 105             return getSomething_cast(pThis);
 106
 107         return FallbackToGetSomethingOf<Base>::get(rId, pThis);
 108     }
 109
 110 }
 111
 112 /** the UNO3_GETIMPLEMENTATION_* macros  implement a static helper function
 113     that gives access to your implementation for a given interface reference,
 114     if possible.
 115
 116     Example:
 117         MyClass* pClass = comphelper::getFromUnoTunnel<MyClass>( xRef );
 118
 119     Usage:
 120         Put a UNO3_GETIMPLEMENTATION_DECL( classname ) inside your class
 121         definition and UNO3_GETIMPLEMENTATION_IMPL( classname ) inside
 122         your cxx file. Your class must inherit css::lang::XUnoTunnel
 123         and export it with queryInterface. Implementation of XUnoTunnel is
 124         done by this macro.
 125 */
 126 #define UNO3_GETIMPLEMENTATION_DECL( classname ) \
 127     static const css::uno::Sequence< sal_Int8 > & getUnoTunnelId() noexcept; \
 128     virtual sal_Int64 SAL_CALL getSomething( const css::uno::Sequence< sal_Int8 >& aIdentifier ) override;
 129
 130 #define UNO3_GETIMPLEMENTATION_BASE_IMPL( classname ) \
 131 const css::uno::Sequence< sal_Int8 > & classname::getUnoTunnelId() noexcept \
 132 { \
 133     static const comphelper::UnoIdInit aId; \
 134     return aId.getSeq(); \
 135 }
 136
 137 #define UNO3_GETIMPLEMENTATION_IMPL( classname )\
 138 UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
 139 sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
 140 { \
 141     return comphelper::getSomethingImpl(rId, this); \
 142 }
 143
 144 #define UNO3_GETIMPLEMENTATION2_IMPL( classname, baseclass )\
 145 UNO3_GETIMPLEMENTATION_BASE_IMPL(classname)\
 146 sal_Int64 SAL_CALL classname::getSomething( const css::uno::Sequence< sal_Int8 >& rId ) \
 147 { \
 148     return comphelper::getSomethingImpl(rId, this, comphelper::FallbackToGetSomethingOf<baseclass>{}); \
 149 }
 150
 151
 152 #endif // INCLUDED_COMPHELPER_SERVICEHELPER_HXX
 153
 154 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */