msaaservice_impl.cxx

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/* -*- 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 <rtl/ref.hxx>
#include <sal/log.hxx>
#include <cppuhelper/implbase.hxx>
#include <cppuhelper/factory.hxx>
#include <cppuhelper/implementationentry.hxx>
#include <cppuhelper/supportsservice.hxx>
 
#include <com/sun/star/lang/XServiceInfo.hpp>
#include <com/sun/star/accessibility/XMSAAService.hpp>
#include <com/sun/star/accessibility/AccessibleRole.hpp>
 
#include <com/sun/star/awt/XExtendedToolkit.hpp>
#include <vcl/svapp.hxx>
#include <vcl/window.hxx>
 
#include <prewin.h>
#include <postwin.h>
 
using namespace ::com::sun::star; // for odk interfaces
using namespace ::com::sun::star::uno; // for basic types
using namespace ::com::sun::star::accessibility;
 
using namespace ::com::sun::star::awt;
 
#include <AccTopWindowListener.hxx>
 
namespace my_sc_impl
{
 
namespace {
 
class MSAAServiceImpl : public ::cppu::WeakImplHelper<
            XMSAAService, lang::XServiceInfo >
{
private:
    rtl::Reference<AccTopWindowListener> m_pTopWindowListener;
 
public:
    MSAAServiceImpl ();
 
    // XComponent - as used by VCL to lifecycle manage this bridge.
    virtual void SAL_CALL dispose() override;
    virtual void SAL_CALL addEventListener( const css::uno::Reference< css::lang::XEventListener >& ) override
    { /* dummy */ }
    virtual void SAL_CALL removeEventListener( const css::uno::Reference< css::lang::XEventListener >& ) override
    { /* dummy */ }
 
    // XMSAAService
    virtual sal_Int64 SAL_CALL getAccObjectPtr(
            sal_Int64 hWnd, sal_Int64 lParam, sal_Int64 wParam) override;
    virtual void SAL_CALL handleWindowOpened(sal_Int64) override;
 
    // XServiceInfo
    virtual OUString SAL_CALL getImplementationName() override;
    virtual sal_Bool SAL_CALL supportsService( OUString const & serviceName ) override;
    virtual Sequence< OUString > SAL_CALL getSupportedServiceNames() override;
};
 
}
 
sal_Int64 MSAAServiceImpl::getAccObjectPtr(
        sal_Int64 hWnd, sal_Int64 lParam, sal_Int64 wParam)
{
    // tdf#155794: this must complete without taking SolarMutex
 
    if (!m_pTopWindowListener.is())
    {
        return 0;
    }
    return m_pTopWindowListener->GetMSComPtr(hWnd, lParam, wParam);
}
 
void MSAAServiceImpl::handleWindowOpened(sal_Int64 nAcc)
{
    SolarMutexGuard g;
 
    SAL_INFO( "iacc2", "Window opened " << nAcc );
 
    if (m_pTopWindowListener.is() && nAcc)
    {
        m_pTopWindowListener->HandleWindowOpened(
            static_cast<css::accessibility::XAccessible*>(
                reinterpret_cast<void*>(nAcc)));
    }
}
 
OUString MSAAServiceImpl::getImplementationName()
{
    return "com.sun.star.accessibility.my_sc_implementation.MSAAService";
}
 
sal_Bool MSAAServiceImpl::supportsService( OUString const & serviceName )
{
    return cppu::supportsService(this, serviceName);
}
 
Sequence< OUString > MSAAServiceImpl::getSupportedServiceNames()
{
   return { "com.sun.star.accessibility.MSAAService" };
}
 
static void AccessBridgeHandleExistingWindow(const Reference< XMSAAService > &xAccMgr,
                                             vcl::Window *pWindow, bool bShow)
{
    if ( pWindow )
    {
        css::uno::Reference< css::accessibility::XAccessible > xAccessible;
 
        SAL_INFO( "iacc2", "Decide whether to register existing window with IAccessible2" );
 
        // Test for combo box - drop down floating windows first
        vcl::Window * pParentWindow = pWindow->GetParent();
 
        if ( pParentWindow )
        {
            try
            {
                // The parent window of a combo box floating window should have the role COMBO_BOX
                css::uno::Reference< css::accessibility::XAccessible > xParentAccessible(pParentWindow->GetAccessible());
                if ( xParentAccessible.is() )
                {
                    css::uno::Reference< css::accessibility::XAccessibleContext > xParentAC( xParentAccessible->getAccessibleContext() );
                    if ( xParentAC.is() && (css::accessibility::AccessibleRole::COMBO_BOX == xParentAC->getAccessibleRole()) )
                    {
                        // O.k. - this is a combo box floating window corresponding to the child of role LIST of the parent.
                        // Let's not rely on a specific child order, just search for the child with the role LIST
                        sal_Int64 nCount = xParentAC->getAccessibleChildCount();
                        for (sal_Int64 n = 0; (n < nCount) && !xAccessible.is(); n++)
                        {
                            css::uno::Reference< css::accessibility::XAccessible > xChild = xParentAC->getAccessibleChild(n);
                            if ( xChild.is() )
                            {
                                css::uno::Reference< css::accessibility::XAccessibleContext > xChildAC = xChild->getAccessibleContext();
                                if ( xChildAC.is() && (css::accessibility::AccessibleRole::LIST == xChildAC->getAccessibleRole()) )
                                {
                                    xAccessible = xChild;
                                }
                            }
                        }
                    }
                }
            }
            catch (css::uno::RuntimeException const&)
            {
                // Ignore show events that throw DisposedExceptions in getAccessibleContext(),
                // but keep revoking these windows in hide(s).
                if (bShow)
                    return;
            }
        }
 
        // We have to rely on the fact that Window::GetAccessible()->getAccessibleContext() returns a valid XAccessibleContext
        // also for other menus than menubar or toplevel popup window. Otherwise we had to traverse the hierarchy to find the
        // context object to this menu floater. This makes the call to Window->IsMenuFloatingWindow() obsolete.
        if ( ! xAccessible.is() )
            xAccessible = pWindow->GetAccessible();
 
        assert( xAccMgr.is() );
        if ( xAccessible.is() )
        {
            xAccMgr->handleWindowOpened(
                    reinterpret_cast<sal_Int64>(xAccessible.get()));
            SAL_INFO( "iacc2", "Decide whether to register existing window with IAccessible2" );
        }
    }
}
 
/*
 * Setup and notify the OS of Accessible peers for all existing windows.
 */
static void AccessBridgeUpdateOldTopWindows( const Reference< XMSAAService > &xAccMgr )
{
    sal_uInt16 nTopWindowCount = static_cast<sal_uInt16>(Application::GetTopWindowCount());
 
    for ( sal_uInt16 i = 0; i < nTopWindowCount; i++ )
    {
        vcl::Window* pTopWindow = Application::GetTopWindow( i );
        css::uno::Reference< css::accessibility::XAccessible > xAccessible = pTopWindow->GetAccessible();
        if ( xAccessible.is() )
        {
            css::uno::Reference< css::accessibility::XAccessibleContext > xAC( xAccessible->getAccessibleContext() );
            if ( xAC.is())
            {
                if ( !xAC->getAccessibleName().isEmpty() )
                    AccessBridgeHandleExistingWindow( xAccMgr, pTopWindow, true );
            }
        }
    }
}
 
MSAAServiceImpl::MSAAServiceImpl()
{
    Reference< XExtendedToolkit > xToolkit(Application::GetVCLToolkit(), UNO_QUERY);
 
    if( xToolkit.is() )
    {
        m_pTopWindowListener.set(new AccTopWindowListener());
        Reference<XTopWindowListener> const xRef(m_pTopWindowListener);
        xToolkit->addTopWindowListener( xRef );
        SAL_INFO( "iacc2", "successfully connected to the toolkit event hose" );
    }
    else
        SAL_WARN( "iacc2", "No VCL toolkit interface to listen to for events");
}
 
void MSAAServiceImpl::dispose()
{
    SolarMutexGuard g;
 
    // As all folders and streams contain references to their parents,
    // we must remove these references so that they will be deleted when
    // the hash_map of the root folder is cleared, releasing all subfolders
    // and substreams which in turn release theirs, etc. When xRootFolder is
    // released when this destructor completes, the folder tree should be
    // deleted fully (and automagically).
    m_pTopWindowListener.clear();
}
 
extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*
winaccessibility_MSAAServiceImpl_get_implementation(
    css::uno::XComponentContext* , css::uno::Sequence<css::uno::Any> const&)
{
    Reference< XMSAAService > xAccMgr( new MSAAServiceImpl() );
 
    AccessBridgeUpdateOldTopWindows( xAccMgr );
 
    SAL_INFO("iacc2", "Created new IAccessible2 service impl.");
 
    xAccMgr->acquire();
    return xAccMgr.get();
}
 
}
 
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