    /* -*- 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 .
     */

    #include <com/sun/star/accessibility/XAccessible.hpp>
    #include <com/sun/star/accessibility/AccessibleStateType.hpp>
    #include <com/sun/star/accessibility/AccessibleEventId.hpp>
    #include <com/sun/star/accessibility/AccessibleRole.hpp>
    #include <com/sun/star/accessibility/XAccessibleEventBroadcaster.hpp>

    #include <vcl/svapp.hxx>

    #include <AccFrameEventListener.hxx>
    #include <AccObjectManagerAgent.hxx>
    #include <unomsaaevent.hxx>

    using namespace com::sun::star::uno;
    using namespace com::sun::star::accessibility;

    #include <vcl/window.hxx>
    #include <toolkit/awt/vclxwindow.hxx>
    #include <vcl/sysdata.hxx>

    AccFrameEventListener::AccFrameEventListener(css::accessibility::XAccessible* pAcc, AccObjectManagerAgent* Agent)
            :AccEventListener(pAcc, Agent)
    {
    }

    AccFrameEventListener::~AccFrameEventListener()
    {
    }

    /**
     *  Uno's event notifier when event is captured
     *  @param AccessibleEventObject    the event object which contains information about event
     */
    void  AccFrameEventListener::notifyEvent( const css::accessibility::AccessibleEventObject& aEvent )
    {
        SolarMutexGuard g;

        switch (aEvent.EventId)
        {
        case AccessibleEventId::CHILD:
            HandleChildChangedEvent(aEvent.OldValue, aEvent.NewValue);
            break;
        case AccessibleEventId::VISIBLE_DATA_CHANGED:
            HandleVisibleDataChangedEvent();
            break;
        case AccessibleEventId::BOUNDRECT_CHANGED:
            HandleBoundrectChangedEvent();
            break;
        default:
            AccEventListener::notifyEvent(aEvent);
            break;
        }
    }

    /**
     *  handle the CHILD event
     *  @param  oldValue    the child to be deleted
     *  @param  newValue    the child to be added
     */
    void AccFrameEventListener::HandleChildChangedEvent(Any oldValue, Any newValue)
    {
        Reference< XAccessible > xChild;
        if( newValue >>= xChild)
        {
            //create a new child
            if(xChild.is())
            {
                XAccessible* pAcc = xChild.get();

                VCLXWindow* pvclwindow =
                    dynamic_cast<VCLXWindow*>(m_xAccessible.get());
                const SystemEnvData* systemdata
                    = pvclwindow->GetWindow()->GetSystemData();

                //add this child
                pAgent->InsertAccObj(pAcc, m_xAccessible.get(),
                        reinterpret_cast<sal_Int64>(systemdata->hWnd));
                //add all oldValue's existing children
                pAgent->InsertChildrenAccObj(pAcc);
                pAgent->NotifyAccEvent(UM_EVENT_CHILD_ADDED, pAcc);
            }
        }
        else if (oldValue >>= xChild)
        {
            //delete a existing child
            if(xChild.is())
            {
                XAccessible* pAcc = xChild.get();
                pAgent->NotifyAccEvent(UM_EVENT_CHILD_REMOVED, pAcc);
                //delete all oldValue's existing children
                pAgent->DeleteChildrenAccObj( pAcc );
                //delete this child
                pAgent->DeleteAccObj( pAcc );
            }
        }

    }

    /**
     *  set the new state and fire the MSAA event
     *  @param state    new state id
     *  @param enable   true if state is set, false if state is unset
     */
    void AccFrameEventListener::SetComponentState(short state, bool enable )
    {
        // only the following state can be fired state event.
        switch (state)
        {
        case AccessibleStateType::ICONIFIED:
            // no msaa state
            break;
        case AccessibleStateType::VISIBLE:
            // UNO !VISIBLE == MSAA INVISIBLE
            if( enable )
                pAgent->IncreaseState(m_xAccessible.get(), AccessibleStateType::VISIBLE);
            else
                pAgent->DecreaseState(m_xAccessible.get(), AccessibleStateType::VISIBLE);
            break;
        case AccessibleStateType::ACTIVE:
            // Only frames should be active
            // no msaa state mapping
            break;
        default:
            break;
        }
    }

    /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

↑ V522 There might be dereferencing of a potential null pointer 'pvclwindow'.