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Diffstat (limited to 'include/comphelper/weakeventlistener.hxx')
| -rw-r--r-- | include/comphelper/weakeventlistener.hxx | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/include/comphelper/weakeventlistener.hxx b/include/comphelper/weakeventlistener.hxx new file mode 100644 index 000000000..d64f302d8 --- /dev/null +++ b/include/comphelper/weakeventlistener.hxx @@ -0,0 +1,183 @@ +/* -*- 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_WEAKEVENTLISTENER_HXX +#define INCLUDED_COMPHELPER_WEAKEVENTLISTENER_HXX + +#include <config_options.h> +#include <cppuhelper/compbase.hxx> +#include <cppuhelper/basemutex.hxx> +#include <cppuhelper/weakref.hxx> +#include <comphelper/comphelperdllapi.h> +#include <com/sun/star/lang/XEventListener.hpp> +#include <com/sun/star/lang/XComponent.hpp> +#include <utility> + +namespace com::sun::star::uno { class XWeak; } + +namespace comphelper +{ + + + //= OWeakListenerAdapterBase + + /** (the base for) an adapter which allows to add as listener to a foreign component, without + being held hard. + + <p>The idea is that this adapter is added as listener to a foreign component, which usually + holds it's listener hard. The adapter itself knows the real listener as weak reference, + thus not affecting its life time.</p> + */ + class OWeakListenerAdapterBase : public cppu::BaseMutex + { + private: + css::uno::WeakReference< css::uno::XInterface > + m_aListener; + css::uno::Reference< css::uno::XInterface > + m_xBroadcaster; + + protected: + css::uno::Reference< css::uno::XInterface > + getListener( ) const + { + return m_aListener.get(); + } + + const css::uno::Reference< css::uno::XInterface >& + getBroadcaster( ) const + { + return m_xBroadcaster; + } + + void resetListener( ) + { + m_aListener.clear(); + } + + + protected: + OWeakListenerAdapterBase( + const css::uno::Reference< css::uno::XWeak >& _rxListener, + css::uno::Reference< css::uno::XInterface > _xBroadcaster + ) + :m_aListener ( _rxListener ) + ,m_xBroadcaster (std::move( _xBroadcaster )) + { + } + + protected: + virtual ~OWeakListenerAdapterBase(); + }; + + + //= OWeakListenerAdapter + + template< class BROADCASTER, class LISTENER > + /** yet another base for weak listener adapters, this time with some type safety + + <p>Note that derived classes need to overwrite all virtual methods of their interface + except XEventListener::disposing, and forward it to their master listener.</p> + + <p>Additionally, derived classes need to add themself as listener to the broadcaster, + as this can't be done in a generic way</p> + */ + class OWeakListenerAdapter + :public ::cppu::WeakComponentImplHelper< LISTENER > + ,public OWeakListenerAdapterBase + { + protected: + /** ctor + <p>Note that derived classes still need to add themself as listener to the broadcaster, + as this can't be done in a generic way</p> + */ + OWeakListenerAdapter( + const css::uno::Reference< css::uno::XWeak >& _rxListener, + const css::uno::Reference< BROADCASTER >& _rxBroadcaster + ); + + protected: + css::uno::Reference< LISTENER > getListener( ) const + { + return css::uno::Reference< LISTENER >( OWeakListenerAdapterBase::getListener(), css::uno::UNO_QUERY ); + } + + // XEventListener overridables + virtual void SAL_CALL disposing( const css::lang::EventObject& Source ) override; + + protected: + // OComponentHelper overridables + // to be overridden, again - the derived class should revoke the listener from the broadcaster + virtual void SAL_CALL disposing( ) override = 0; + }; + + + //= OWeakEventListenerAdapter + + typedef OWeakListenerAdapter < css::lang::XComponent + , css::lang::XEventListener + > OWeakEventListenerAdapter_Base; + /** the most simple listener adapter: for XEventListeners at XComponents + */ + class UNLESS_MERGELIBS(COMPHELPER_DLLPUBLIC) OWeakEventListenerAdapter final : public OWeakEventListenerAdapter_Base + { + public: + OWeakEventListenerAdapter( + css::uno::Reference< css::uno::XWeak > const & _rxListener, + css::uno::Reference< css::lang::XComponent > const & _rxBroadcaster + ); + + // nothing to do except an own ctor - the forwarding of the "disposing" is already done + // in the base class + + private: + using OWeakEventListenerAdapter_Base::disposing; + virtual void SAL_CALL disposing( ) override; + }; + + + //= OWeakListenerAdapter + + + template< class BROADCASTER, class LISTENER > + OWeakListenerAdapter< BROADCASTER, LISTENER >::OWeakListenerAdapter( + const css::uno::Reference< css::uno::XWeak >& _rxListener, + const css::uno::Reference< BROADCASTER >& _rxBroadcaster + ) + : ::cppu::WeakComponentImplHelper< LISTENER >( m_aMutex ) + , OWeakListenerAdapterBase( _rxListener, _rxBroadcaster ) + { + } + + + template< class BROADCASTER, class LISTENER > + void SAL_CALL OWeakListenerAdapter< BROADCASTER, LISTENER >::disposing( const css::lang::EventObject& _rSource ) + { + css::uno::Reference< LISTENER > xListener( getListener() ); + if ( xListener.is() ) + xListener->disposing( _rSource ); + } + + +} // namespace comphelper + + +#endif // INCLUDED_COMPHELPER_WEAKEVENTLISTENER_HXX + + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |