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| -rw-r--r-- | include/cppuhelper/weakref.hxx | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/include/cppuhelper/weakref.hxx b/include/cppuhelper/weakref.hxx new file mode 100644 index 000000000..ff4d034ca --- /dev/null +++ b/include/cppuhelper/weakref.hxx @@ -0,0 +1,196 @@ +/* -*- 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_CPPUHELPER_WEAKREF_HXX +#define INCLUDED_CPPUHELPER_WEAKREF_HXX + +#include "sal/config.h" + +#include <cstddef> + +#include "com/sun/star/uno/Reference.hxx" +#include "com/sun/star/uno/XInterface.hpp" +#include "cppuhelper/cppuhelperdllapi.h" + + +namespace com +{ +namespace sun +{ +namespace star +{ +namespace uno +{ + +class OWeakRefListener; + +/** The WeakReferenceHelper holds a weak reference to an object. + + That object must implement the css::uno::XWeak interface. + + The WeakReferenceHelper itself is *not* thread safe, just as + Reference itself isn't, but the implementation of the listeners etc. + behind it *is* thread-safe, so multiple threads can have their own + WeakReferences to the same XWeak object. +*/ +class CPPUHELPER_DLLPUBLIC WeakReferenceHelper +{ +public: + /** Default ctor. Creates an empty weak reference. + */ + WeakReferenceHelper() + : m_pImpl( NULL ) + {} + + /** Copy ctor. Initialize this reference with the same interface as in rWeakRef. + + @param rWeakRef another weak ref + */ + WeakReferenceHelper( const WeakReferenceHelper & rWeakRef ); + +#if defined LIBO_INTERNAL_ONLY + WeakReferenceHelper(WeakReferenceHelper && other) noexcept : m_pImpl(other.m_pImpl) + { other.m_pImpl = nullptr; } +#endif + + /** Initialize this reference with the hard interface reference xInt. If the implementation + behind xInt does not support XWeak or xInt is null then this reference will be null. + + @param xInt another hard interface reference + */ + WeakReferenceHelper( const css::uno::Reference< css::uno::XInterface > & xInt ); + + /** Releases this reference. + */ + ~WeakReferenceHelper(); + + /** Releases this reference and takes over rWeakRef. + + @param rWeakRef another weak ref + */ + WeakReferenceHelper & SAL_CALL operator = ( const WeakReferenceHelper & rWeakRef ); + +#if defined LIBO_INTERNAL_ONLY + WeakReferenceHelper & SAL_CALL operator =(WeakReferenceHelper && other); +#endif + + /** Releases this reference and takes over hard reference xInt. + If the implementation behind xInt does not support XWeak + or XInt is null, then this reference is null. + + @param xInt another hard reference + */ + WeakReferenceHelper & SAL_CALL operator = ( + const css::uno::Reference< css::uno::XInterface > & xInt ); + + /** Returns true if both weak refs reference to the same object. + + @param rObj another weak ref + @return true, if both weak refs reference to the same object. + */ + bool SAL_CALL operator == ( const WeakReferenceHelper & rObj ) const + { return (get() == rObj.get()); } + + /** Gets a hard reference to the object. + + @return hard reference or null, if the weakly referenced interface has gone + */ + css::uno::Reference< css::uno::XInterface > SAL_CALL get() const; + + /** Gets a hard reference to the object. + + @return hard reference or null, if the weakly referenced interface has gone + */ + SAL_CALL operator Reference< XInterface > () const + { return get(); } + + /** Releases this reference. + + @since UDK 3.2.12 + */ + void SAL_CALL clear(); + +protected: + /// @cond INTERNAL + OWeakRefListener * m_pImpl; + /// @endcond +}; + +/** The WeakReference<> holds a weak reference to an object. + + That object must implement the css::uno::XWeak interface. + + The WeakReference itself is *not* thread safe, just as + Reference itself isn't, but the implementation of the listeners etc. + behind it *is* thread-safe, so multiple threads can have their own + WeakReferences to the same XWeak object. + + @tparam interface_type type of interface +*/ +template< class interface_type > +class SAL_WARN_UNUSED WeakReference : public WeakReferenceHelper +{ +public: + /** Default ctor. Creates an empty weak reference. + */ + WeakReference() + : WeakReferenceHelper() + {} + + /** Copy ctor. Initialize this reference with a hard reference. + + @param rRef another hard ref + */ + WeakReference( const Reference< interface_type > & rRef ) + : WeakReferenceHelper( rRef ) + {} + + /** Releases this reference and takes over hard reference xInt. + If the implementation behind xInt does not support XWeak + or XInt is null, then this reference is null. + + @param xInt another hard reference + + @since UDK 3.2.12 + */ + WeakReference & SAL_CALL operator = ( + const css::uno::Reference< interface_type > & xInt ) + { WeakReferenceHelper::operator=(xInt); return *this; } + +#if defined LIBO_INTERNAL_ONLY + WeakReference & SAL_CALL operator = ( + css::uno::Reference< interface_type > && xInt ) + { WeakReferenceHelper::operator=(std::move(xInt)); return *this; } +#endif + + /** Gets a hard reference to the object. + + @return hard reference or null, if the weakly referenced interface has gone + */ + SAL_CALL operator Reference< interface_type > () const + { return Reference< interface_type >::query( get() ); } +}; + +} +} +} +} + +#endif + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |