toolkit/source/helper/accessibilityclient.cxx

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  30
  31 // MARKER(update_precomp.py): autogen include statement, do not remove
  32 #include "precompiled_toolkit.hxx"
  33 #include <toolkit/helper/accessibilityclient.hxx>
  34 #include <toolkit/helper/accessiblefactory.hxx>
  35 #include <osl/module.h>
  36 #include <osl/diagnose.h>
  37 #include <tools/solar.h>
  38
  39 // #define UNLOAD_ON_LAST_CLIENT_DYING
  40     // this is not recommended currently. If enabled, the implementation will log
  41     // the number of active clients, and unload the acc library when the last client
  42     // goes away.
  43     // Sounds like a good idea, unfortunately, there's no guarantee that all objects
  44     // implemented in this library are already dead.
  45     // Iow, just because an object implementing an XAccessible (implemented in this lib
  46     // here) died, it's not said that everybody released all references to the
  47     // XAccessibleContext used by this component, and implemented in the acc lib.
  48     // So we cannot really unload the lib.
  49     //
  50     // Alternatively, if the lib would us own "usage counting", i.e. every component
  51     // implemented therein would affect a static ref count, the acc lib could care
  52     // for unloading itself.
  53
  54 //........................................................................
  55 namespace toolkit
  56 {
  57 //........................................................................
  58
  59     using namespace ::com::sun::star::uno;
  60     using namespace ::com::sun::star::accessibility;
  61
  62     namespace
  63     {
  64 #ifdef UNLOAD_ON_LAST_CLIENT_DYING
  65         static oslInterlockedCount                      s_nAccessibilityClients = 0;
  66 #endif // UNLOAD_ON_LAST_CLIENT_DYING
  67         static oslModule                                s_hAccessibleImplementationModule = NULL;
  68         static GetStandardAccComponentFactory           s_pAccessibleFactoryFunc = NULL;
  69         static ::rtl::Reference< IAccessibleFactory >   s_pFactory;
  70     }
  71
  72     //====================================================================
  73     //= AccessibleDummyFactory
  74     //====================================================================
  75     class AccessibleDummyFactory : public IAccessibleFactory
  76     {
  77     public:
  78         AccessibleDummyFactory();
  79
  80     protected:
  81         virtual ~AccessibleDummyFactory();
  82
  83     private:
  84         AccessibleDummyFactory( const AccessibleDummyFactory& );            // never implemented
  85         AccessibleDummyFactory& operator=( const AccessibleDummyFactory& ); // never implemented
  86
  87         oslInterlockedCount m_refCount;
  88
  89     public:
  90         // IReference
  91         virtual oslInterlockedCount SAL_CALL acquire();
  92         virtual oslInterlockedCount SAL_CALL release();
  93
  94         // IAccessibleFactory
  95         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
  96                 createAccessibleContext( VCLXButton* /*_pXWindow*/ )
  97         {
  98             return NULL;
  99         }
 100         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 101                 createAccessibleContext( VCLXCheckBox* /*_pXWindow*/ )
 102         {
 103             return NULL;
 104         }
 105         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 106                 createAccessibleContext( VCLXRadioButton* /*_pXWindow*/ )
 107         {
 108             return NULL;
 109         }
 110         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 111                 createAccessibleContext( VCLXListBox* /*_pXWindow*/ )
 112         {
 113             return NULL;
 114         }
 115         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 116                 createAccessibleContext( VCLXFixedHyperlink* /*_pXWindow*/ )
 117         {
 118             return NULL;
 119         }
 120         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 121                 createAccessibleContext( VCLXFixedText* /*_pXWindow*/ )
 122         {
 123             return NULL;
 124         }
 125         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 126                 createAccessibleContext( VCLXScrollBar* /*_pXWindow*/ )
 127         {
 128             return NULL;
 129         }
 130         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 131                 createAccessibleContext( VCLXEdit* /*_pXWindow*/ )
 132         {
 133             return NULL;
 134         }
 135         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 136                 createAccessibleContext( VCLXComboBox* /*_pXWindow*/ )
 137         {
 138             return NULL;
 139         }
 140         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 141                 createAccessibleContext( VCLXToolBox* /*_pXWindow*/ )
 142         {
 143             return NULL;
 144         }
 145         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessibleContext >
 146                 createAccessibleContext( VCLXWindow* /*_pXWindow*/ )
 147         {
 148             return NULL;
 149         }
 150         ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >
 151                 createAccessible( Menu* /*_pMenu*/, sal_Bool /*_bIsMenuBar*/ )
 152         {
 153             return NULL;
 154         }
 155     };
 156
 157     //--------------------------------------------------------------------
 158     AccessibleDummyFactory::AccessibleDummyFactory()
 159     {
 160     }
 161
 162     //--------------------------------------------------------------------
 163     AccessibleDummyFactory::~AccessibleDummyFactory()
 164     {
 165     }
 166
 167     //--------------------------------------------------------------------
 168     oslInterlockedCount SAL_CALL AccessibleDummyFactory::acquire()
 169     {
 170         return osl_incrementInterlockedCount( &m_refCount );
 171     }
 172
 173     //--------------------------------------------------------------------
 174     oslInterlockedCount SAL_CALL AccessibleDummyFactory::release()
 175     {
 176         if ( 0 == osl_decrementInterlockedCount( &m_refCount ) )
 177         {
 178             delete this;
 179             return 0;
 180         }
 181         return m_refCount;
 182     }
 183
 184     //====================================================================
 185     //= AccessibilityClient
 186     //====================================================================
 187     //--------------------------------------------------------------------
 188     AccessibilityClient::AccessibilityClient()
 189         :m_bInitialized( false )
 190     {
 191     }
 192
 193     //--------------------------------------------------------------------
 194     extern "C" { static void SAL_CALL thisModule() {} }
 195
 196     void AccessibilityClient::ensureInitialized()
 197     {
 198         if ( m_bInitialized )
 199             return;
 200
 201         ::osl::MutexGuard aGuard( ::osl::Mutex::getGlobalMutex() );
 202
 203 #ifdef UNLOAD_ON_LAST_CLIENT_DYING
 204         if ( 1 == osl_incrementInterlockedCount( &s_nAccessibilityClients ) )
 205         {   // the first client
 206 #endif // UNLOAD_ON_LAST_CLIENT_DYING
 207             // load the library implementing the factory
 208             if ( !s_pFactory.get() )
 209             {
 210                 const ::rtl::OUString sModuleName = ::rtl::OUString::createFromAscii(
 211                     SVLIBRARY( "acc" )
 212                 );
 213                 s_hAccessibleImplementationModule = osl_loadModuleRelative( &thisModule, sModuleName.pData, 0 );
 214                 if ( s_hAccessibleImplementationModule != NULL )
 215                 {
 216                     const ::rtl::OUString sFactoryCreationFunc =
 217                         ::rtl::OUString::createFromAscii( "getStandardAccessibleFactory" );
 218                     s_pAccessibleFactoryFunc = (GetStandardAccComponentFactory)
 219                         osl_getFunctionSymbol( s_hAccessibleImplementationModule, sFactoryCreationFunc.pData );
 220
 221                 }
 222                 OSL_ENSURE( s_pAccessibleFactoryFunc, "AccessibilityClient::ensureInitialized: could not load the library, or not retrieve the needed symbol!" );
 223
 224                 // get a factory instance
 225                 if ( s_pAccessibleFactoryFunc )
 226                 {
 227                     IAccessibleFactory* pFactory = static_cast< IAccessibleFactory* >( (*s_pAccessibleFactoryFunc)() );
 228                     OSL_ENSURE( pFactory, "AccessibilityClient::ensureInitialized: no factory provided by the A11Y lib!" );
 229                     if ( pFactory )
 230                     {
 231                         s_pFactory = pFactory;
 232                         pFactory->release();
 233                     }
 234                 }
 235             }
 236
 237             if ( !s_pFactory.get() )
 238                 // the attempt to load the lib, or to create the factory, failed
 239                 // -> fall back to a dummy factory
 240                 s_pFactory = new AccessibleDummyFactory;
 241 #ifdef UNLOAD_ON_LAST_CLIENT_DYING
 242         }
 243 #endif
 244
 245         m_bInitialized = true;
 246     }
 247
 248     //--------------------------------------------------------------------
 249     AccessibilityClient::~AccessibilityClient()
 250     {
 251         if ( m_bInitialized )
 252         {
 253             ::osl::MutexGuard aGuard( ::osl::Mutex::getGlobalMutex() );
 254
 255 #ifdef UNLOAD_ON_LAST_CLIENT_DYING
 256             if( 0 == osl_decrementInterlockedCount( &s_nAccessibilityClients ) )
 257             {
 258                 s_pFactory = NULL;
 259                 s_pAccessibleFactoryFunc = NULL;
 260                 if ( s_hAccessibleImplementationModule )
 261                 {
 262                     osl_unloadModule( s_hAccessibleImplementationModule );
 263                     s_hAccessibleImplementationModule = NULL;
 264                 }
 265             }
 266 #endif // UNLOAD_ON_LAST_CLIENT_DYING
 267         }
 268     }
 269
 270     //--------------------------------------------------------------------
 271     IAccessibleFactory& AccessibilityClient::getFactory()
 272     {
 273         ensureInitialized();
 274         OSL_ENSURE( s_pFactory.is(), "AccessibilityClient::getFactory: at least a dummy factory should have been created!" );
 275         return *s_pFactory;
 276     }
 277
 278 //........................................................................
 279 }   // namespace toolkit
 280 //........................................................................