/**************************************************************
 * 
 * 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
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/


// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_svtools.hxx"
#include "svtaccessiblefactory.hxx"
#include <osl/module.h>

// #define UNLOAD_ON_LAST_CLIENT_DYING
    // this is not recommended currently. If enabled, the implementation will log
    // the number of active clients, and unload the acc library when the last client
    // goes away.
    // Sounds like a good idea, unfortunately, there's no guarantee that all objects
    // implemented in this library are already dead.
    // Iow, just because an object implementing an XAccessible (implemented in this lib
    // here) died, it's not said that everybody released all references to the
    // XAccessibleContext used by this component, and implemented in the acc lib.
    // So we cannot really unload the lib.
    //
    // Alternatively, if the lib would us own "usage counting", i.e. every component
    // implemented therein would affect a static ref count, the acc lib could care
    // for unloading itself.

//........................................................................
namespace svt
{
//........................................................................

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

    namespace
    {
#ifdef UNLOAD_ON_LAST_CLIENT_DYING
        static oslInterlockedCount                      s_nAccessibleFactoryAccesss = 0;
#endif // UNLOAD_ON_LAST_CLIENT_DYING
        static oslModule                                s_hAccessibleImplementationModule = NULL;
        static GetSvtAccessibilityComponentFactory      s_pAccessibleFactoryFunc = NULL;
        static ::rtl::Reference< IAccessibleFactory >   s_pFactory;

        //====================================================================
        //= AccessibleDummyFactory
        //====================================================================
        class AccessibleDummyFactory : public IAccessibleFactory
        {
        public:
            AccessibleDummyFactory();

        protected:
            virtual ~AccessibleDummyFactory();

        private:
            AccessibleDummyFactory( const AccessibleDummyFactory& );            // never implemented
            AccessibleDummyFactory& operator=( const AccessibleDummyFactory& ); // never implemented

            oslInterlockedCount m_refCount;

        public:
            // IReference
	        virtual oslInterlockedCount SAL_CALL acquire();
	        virtual oslInterlockedCount SAL_CALL release();

            // IAccessibleFactory
            virtual IAccessibleTabListBox*
                createAccessibleTabListBox(
		            const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*rxParent*/,
		            SvHeaderTabListBox& /*rBox*/
                ) const
            {
                return NULL;
            }

            virtual IAccessibleBrowseBox*
                createAccessibleBrowseBox(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_rxParent*/,
                    IAccessibleTableProvider& /*_rBrowseBox*/
		        ) const
            {
                return NULL;
            }

			virtual table::IAccessibleTableControl*
                createAccessibleTableControl(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_rxParent*/,
                    table::IAccessibleTable& /*_rTable*/
		        ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
		        createAccessibleIconChoiceCtrl(
                    SvtIconChoiceCtrl& /*_rIconCtrl*/,
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_xParent*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
		        createAccessibleTabBar(
                    TabBar& /*_rTabBar*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
		        createAccessibleTextWindowContext(
                    VCLXWindow* /*pVclXWindow*/, TextEngine& /*rEngine*/, TextView& /*rView*/, bool /*bCompoundControlChild*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createAccessibleTreeListBox(
                    SvTreeListBox& /*_rListBox*/,
				    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_xParent*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createAccessibleBrowseBoxHeaderBar(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*rxParent*/,
                    IAccessibleTableProvider& /*_rOwningTable*/,
                    AccessibleBrowseBoxObjType /*_eObjType*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createAccessibleBrowseBoxTableCell(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_rxParent*/,
				    IAccessibleTableProvider& /*_rBrowseBox*/,
				    const ::com::sun::star::uno::Reference< ::com::sun::star::awt::XWindow >& /*_xFocusWindow*/,
				    sal_Int32 /*_nRowId*/,
				    sal_uInt16 /*_nColId*/,
                    sal_Int32 /*_nOffset*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createAccessibleBrowseBoxHeaderCell(
                    sal_Int32 /*_nColumnRowId*/,
				    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*rxParent*/,
				    IAccessibleTableProvider& /*_rBrowseBox*/,
				    const ::com::sun::star::uno::Reference< ::com::sun::star::awt::XWindow >& /*_xFocusWindow*/,
				    AccessibleBrowseBoxObjType  /*_eObjType*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createAccessibleCheckBoxCell(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*_rxParent*/,
				    IAccessibleTableProvider& /*_rBrowseBox*/,
				    const ::com::sun::star::uno::Reference< ::com::sun::star::awt::XWindow >& /*_xFocusWindow*/,
				    sal_Int32 /*_nRowPos*/,
				    sal_uInt16 /*_nColPos*/,
				    const TriState& /*_eState*/,
				    sal_Bool /*_bEnabled*/,
				    sal_Bool /*_bIsTriState*/
                ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
                createEditBrowseBoxTableCellAccess(
			        const ::com::sun::star::uno::Reference< com::sun::star::accessibility::XAccessible >& /*_rxParent*/,
			        const ::com::sun::star::uno::Reference< com::sun::star::accessibility::XAccessible >& /*_rxControlAccessible*/,
			        const ::com::sun::star::uno::Reference< ::com::sun::star::awt::XWindow >& /*_rxFocusWindow*/,
                    IAccessibleTableProvider& /*_rBrowseBox*/,
			        sal_Int32 /*_nRowPos*/,
			        sal_uInt16 /*_nColPos*/
		        ) const
            {
                return NULL;
            }

            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
                createAccessibleToolPanelDeck(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*i_rAccessibleParent*/,
                    ::svt::ToolPanelDeck& /*i_rPanelDeck*/
                )
            {
                return NULL;
            }
            virtual ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
                createAccessibleToolPanelTabBar(
                    const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& /*i_rAccessibleParent*/,
                    ::svt::IToolPanelDeck& /*i_rPanelDeck*/,
                    ::svt::PanelTabBar& /*i_rTabBar*/
                )
            {
                return NULL;
            }
        };

        //----------------------------------------------------------------
        AccessibleDummyFactory::AccessibleDummyFactory()
        {
        }

        //----------------------------------------------------------------
        AccessibleDummyFactory::~AccessibleDummyFactory()
        {
        }

        //----------------------------------------------------------------
	    oslInterlockedCount SAL_CALL AccessibleDummyFactory::acquire()
        {
            return osl_incrementInterlockedCount( &m_refCount );
        }

	    //----------------------------------------------------------------
	    oslInterlockedCount SAL_CALL AccessibleDummyFactory::release()
        {
            if ( 0 == osl_decrementInterlockedCount( &m_refCount ) )
            {
                delete this;
                return 0;
            }
            return m_refCount;
        }
    }

    //====================================================================
    //= AccessibleFactoryAccess
    //====================================================================
    //--------------------------------------------------------------------
    AccessibleFactoryAccess::AccessibleFactoryAccess()
        :m_bInitialized( false )
    {
    }

    //--------------------------------------------------------------------
    extern "C" { static void SAL_CALL thisModule() {} }

    void AccessibleFactoryAccess::ensureInitialized()
    {
        if ( m_bInitialized )
            return;

        ::osl::MutexGuard aGuard( ::osl::Mutex::getGlobalMutex() );

#ifdef UNLOAD_ON_LAST_CLIENT_DYING
        if ( 1 == osl_incrementInterlockedCount( &s_nAccessibleFactoryAccesss ) )
        {   // the first client
#endif // UNLOAD_ON_LAST_CLIENT_DYING
            // load the library implementing the factory
            if ( !s_pFactory.get() )
            {
                const ::rtl::OUString sModuleName = ::rtl::OUString::createFromAscii(
                    SVLIBRARY( "acc" )
                );
                s_hAccessibleImplementationModule = osl_loadModuleRelative( &thisModule, sModuleName.pData, 0 );
                if ( s_hAccessibleImplementationModule != NULL )
                {
                    const ::rtl::OUString sFactoryCreationFunc =
                        ::rtl::OUString::createFromAscii( "getSvtAccessibilityComponentFactory" );
                    s_pAccessibleFactoryFunc = (GetSvtAccessibilityComponentFactory)
                        osl_getFunctionSymbol( s_hAccessibleImplementationModule, sFactoryCreationFunc.pData );

                }
                OSL_ENSURE( s_pAccessibleFactoryFunc, "ac_registerClient: could not load the library, or not retrieve the needed symbol!" );

                // get a factory instance
                if ( s_pAccessibleFactoryFunc )
                {
                    IAccessibleFactory* pFactory = static_cast< IAccessibleFactory* >( (*s_pAccessibleFactoryFunc)() );
                    if ( pFactory )
                    {
                        s_pFactory = pFactory;
                        pFactory->release();
                    }
                }
            }

            if ( !s_pFactory.get() )
                // the attempt to load the lib, or to create the factory, failed
                // -> fall back to a dummy factory
                s_pFactory = new AccessibleDummyFactory;
#ifdef UNLOAD_ON_LAST_CLIENT_DYING
        }
#endif

        m_bInitialized = true;
    }

    //--------------------------------------------------------------------
    AccessibleFactoryAccess::~AccessibleFactoryAccess()
    {
        if ( m_bInitialized )
        {
            ::osl::MutexGuard aGuard( ::osl::Mutex::getGlobalMutex() );

#ifdef UNLOAD_ON_LAST_CLIENT_DYING
            if( 0 == osl_decrementInterlockedCount( &s_nAccessibleFactoryAccesss ) )
            {
                s_pFactory = NULL;
                s_pAccessibleFactoryFunc = NULL;
                if ( s_hAccessibleImplementationModule )
                {
                    osl_unloadModule( s_hAccessibleImplementationModule );
                    s_hAccessibleImplementationModule = NULL;
                }
            }
#endif // UNLOAD_ON_LAST_CLIENT_DYING
        }
    }

    //--------------------------------------------------------------------
    IAccessibleFactory& AccessibleFactoryAccess::getFactory()
    {
        ensureInitialized();
        DBG_ASSERT( s_pFactory.is(), "AccessibleFactoryAccess::getFactory: at least a dummy factory should have been created!" );
        return *s_pFactory;
    }

//........................................................................
}   // namespace svt
//........................................................................