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| -rw-r--r-- | include/comphelper/accessiblecontexthelper.hxx | 219 |
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diff --git a/include/comphelper/accessiblecontexthelper.hxx b/include/comphelper/accessiblecontexthelper.hxx new file mode 100644 index 000000000..dc367fbe1 --- /dev/null +++ b/include/comphelper/accessiblecontexthelper.hxx @@ -0,0 +1,219 @@ +/* -*- 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_ACCESSIBLECONTEXTHELPER_HXX +#define INCLUDED_COMPHELPER_ACCESSIBLECONTEXTHELPER_HXX + +#include <cppuhelper/compbase2.hxx> +#include <cppuhelper/basemutex.hxx> +#include <com/sun/star/accessibility/XAccessibleContext2.hpp> +#include <com/sun/star/accessibility/XAccessibleEventBroadcaster.hpp> +#include <comphelper/accessibleeventnotifier.hxx> +#include <comphelper/comphelperdllapi.h> +#include <comphelper/solarmutex.hxx> + + +namespace comphelper +{ + + + //= OAccessibleContextHelper + + + typedef ::cppu::WeakAggComponentImplHelper2 < css::accessibility::XAccessibleContext2, + css::accessibility::XAccessibleEventBroadcaster + > OAccessibleContextHelper_Base; + + /** helper class for implementing an AccessibleContext + */ + class COMPHELPER_DLLPUBLIC OAccessibleContextHelper + :public ::cppu::BaseMutex + ,public OAccessibleContextHelper_Base + { + friend class OContextEntryGuard; + private: + css::uno::WeakReference< css::accessibility::XAccessible > m_aCreator; // the XAccessible which created our XAccessibleContext + AccessibleEventNotifier::TClientId m_nClientId; + + protected: + virtual ~OAccessibleContextHelper( ) override; + + OAccessibleContextHelper( ); + + /** late construction + @param _rxAccessible + the Accessible object which created this context. + <p>If your derived implementation implements the XAccessible (and does not follow the proposed + separation of XAccessible from XAccessibleContext), you may pass <code>this</code> here.</p> + + <p>The object is hold weak, so its life time is not affected.</p> + + <p>The object is needed for performance reasons: for <method>getAccessibleIndexInParent</method>, + all children (which are XAccessible's theirself) of our parent have to be asked. If we know our + XAccessible, we can compare it with all the children, instead of asking all children for their + context and comparing this context with ourself.</p> + */ + void lateInit( const css::uno::Reference< css::accessibility::XAccessible >& _rxAccessible ); + + /** retrieves the creator previously set with <method>lateInit</method> + */ + css::uno::Reference< css::accessibility::XAccessible > + getAccessibleCreator( ) const; + + public: + // XAccessibleEventBroadcaster + virtual void SAL_CALL addAccessibleEventListener( const css::uno::Reference< css::accessibility::XAccessibleEventListener >& xListener ) override; + virtual void SAL_CALL removeAccessibleEventListener( const css::uno::Reference< css::accessibility::XAccessibleEventListener >& xListener ) override; + + // XAccessibleContext - still waiting to be overwritten + virtual sal_Int32 SAL_CALL getAccessibleChildCount( ) override = 0; + virtual css::uno::Reference< css::accessibility::XAccessible > SAL_CALL getAccessibleChild( sal_Int32 i ) override = 0; + virtual css::uno::Reference< css::accessibility::XAccessible > SAL_CALL getAccessibleParent( ) override = 0; + virtual sal_Int16 SAL_CALL getAccessibleRole( ) override = 0; + virtual OUString SAL_CALL getAccessibleDescription( ) override = 0; + virtual OUString SAL_CALL getAccessibleName( ) override = 0; + virtual css::uno::Reference< css::accessibility::XAccessibleRelationSet > SAL_CALL getAccessibleRelationSet( ) override = 0; + virtual css::uno::Reference< css::accessibility::XAccessibleStateSet > SAL_CALL getAccessibleStateSet( ) override = 0; + + // XAccessibleContext2 - default implementation + virtual OUString SAL_CALL getAccessibleId( ) override; + + // XAccessibleContext - default implementations + /** default implementation for retrieving the index of this object within the parent + <p>This basic implementation here returns the index <code>i</code> of the child for which + <code><parent>.getAccessibleChild( i )</code> equals our creator.</p> + */ + virtual sal_Int32 SAL_CALL getAccessibleIndexInParent( ) override; + /** default implementation for retrieving the locale + <p>This basic implementation returns the locale of the parent context, + as retrieved via getAccessibleParent()->getAccessibleContext.</p> + */ + virtual css::lang::Locale SAL_CALL getLocale( ) override; + + protected: + // OComponentHelper + virtual void SAL_CALL disposing() override; + + protected: + // helper + /** notifies all AccessibleEventListeners of a certain event + + @precond not to be called with our mutex locked + @param _nEventId + the id of the event. See AccessibleEventType + @param _rOldValue + the old value to be notified + @param _rNewValue + the new value to be notified + */ + void NotifyAccessibleEvent( + const sal_Int16 _nEventId, + const css::uno::Any& _rOldValue, + const css::uno::Any& _rNewValue + ); + + // life time control + /// checks whether the object is alive (returns <TRUE/> then) or disposed + bool isAlive() const; + /// checks for being alive. If the object is already disposed (i.e. not alive), an exception is thrown. + void ensureAlive() const; + + /** ensures that the object is disposed. + @precond + to be called from within the destructor of your derived class only! + */ + void ensureDisposed( ); + + /** shortcut for retrieving the context of the parent (returned by getAccessibleParent) + */ + css::uno::Reference< css::accessibility::XAccessibleContext > + implGetParentContext(); + + // access to the base class' broadcast helper/mutex + ::osl::Mutex& GetMutex() { return m_aMutex; } + }; + + + //= OContextEntryGuard + + /** helper class for guarding the entry into OAccessibleContextHelper methods. + + <p>The class has two responsibilities: + <ul><li>it locks the mutex of an OAccessibleContextHelper instance, as long as the guard lives</li> + <li>it checks if a given OAccessibleContextHelper instance is alive, else an exception is thrown + our of the constructor of the guard</li> + </ul> + <br/> + This makes it your first choice (hopefully :) for guarding any interface method implementations of + you derived class. + </p> + */ + class OContextEntryGuard : public ::osl::ClearableMutexGuard + { + public: + /** constructs the guard + + <p>The given context (it's mutex, respectively) is locked, and an exception is thrown if the context + is not alive anymore. In the latter case, of course, the mutex is freed, again.</p> + + @param _pContext + the context which shall be guarded + @precond <arg>_pContext</arg> != NULL + */ + inline OContextEntryGuard( OAccessibleContextHelper* _pContext ); + }; + + + inline OContextEntryGuard::OContextEntryGuard( OAccessibleContextHelper* _pContext ) + : ::osl::ClearableMutexGuard( _pContext->GetMutex() ) + { + _pContext->ensureAlive(); + } + + + //= OExternalLockGuard + + class OExternalLockGuard + :public osl::Guard<SolarMutex> + ,public OContextEntryGuard + { + public: + inline OExternalLockGuard( OAccessibleContextHelper* _pContext ); + }; + + + inline OExternalLockGuard::OExternalLockGuard( OAccessibleContextHelper* _pContext ) + :osl::Guard<SolarMutex>( SolarMutex::get() ) + ,OContextEntryGuard( _pContext ) + { + // Only lock the external mutex, + // release the ::osl::Mutex of the OAccessibleContextHelper instance. + // If you call into another UNO object with locked ::osl::Mutex, + // this may lead to dead locks. + clear(); + } + + +} // namespace comphelper + + +#endif // INCLUDED_COMPHELPER_ACCESSIBLECONTEXTHELPER_HXX + + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |