include/comphelper/weakeventlistener.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_COMPHELPER_WEAKEVENTLISTENER_HXX
  21 #define INCLUDED_COMPHELPER_WEAKEVENTLISTENER_HXX
  22
  23 #include <cppuhelper/compbase1.hxx>
  24 #include <com/sun/star/lang/XComponent.hpp>
  25 #include <com/sun/star/uno/XWeak.hpp>
  26 #include <cppuhelper/weakref.hxx>
  27 #include <comphelper/broadcasthelper.hxx>
  28 #include <comphelper/comphelperdllapi.h>
  29
  30 //.........................................................................
  31 namespace comphelper
  32 {
  33 //.........................................................................
  34
  35     //=====================================================================
  36     //= OWeakListenerAdapterBase
  37     //=====================================================================
  38     /** (the base for) an adapter which allows to add as listener to a foreign component, without
  39         being held hard.
  40
  41         <p>The idea is that this adapter is added as listener to a foreign component, which usually
  42         holds it's listener hard. The adapter itself knows the real listener as weak reference,
  43         thus not affecting it's life time.</p>
  44     */
  45     class OWeakListenerAdapterBase : public OBaseMutex
  46     {
  47     private:
  48         ::com::sun::star::uno::WeakReference< ::com::sun::star::uno::XInterface >
  49                 m_aListener;
  50         ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface >
  51                 m_xBroadcaster;
  52
  53     protected:
  54         inline ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface >
  55                 getListener( ) const
  56         {
  57             return m_aListener.get();
  58         }
  59
  60         inline const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface >&
  61                 getBroadcaster( ) const
  62         {
  63             return m_xBroadcaster;
  64         }
  65
  66         inline void resetListener( )
  67         {
  68             m_aListener.clear();
  69         }
  70
  71
  72     protected:
  73         inline OWeakListenerAdapterBase(
  74             const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XWeak >& _rxListener,
  75             const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface >& _rxBroadcaster
  76         )
  77             :m_aListener    (  _rxListener )
  78             ,m_xBroadcaster ( _rxBroadcaster )
  79         {
  80         }
  81
  82     protected:
  83         virtual ~OWeakListenerAdapterBase();
  84     };
  85
  86
  87     //=====================================================================
  88     //= OWeakListenerAdapter
  89     //=====================================================================
  90     template< class BROADCASTER, class LISTENER >
  91     /** yet another base for weak listener adapters, this time with some type safety
  92
  93         <p>Note that derived classes need to overwrite all virtual methods of their interface
  94         except XEventListener::disposing, and forward it to their master listener.</p>
  95
  96         <p>Addtionally, derived classes need to add themself as listener to the broadcaster,
  97         as this can't be done in a generic way</p>
  98     */
  99     class OWeakListenerAdapter
 100             :public ::cppu::WeakComponentImplHelper1 < LISTENER >
 101             ,public OWeakListenerAdapterBase
 102     {
 103     protected:
 104         /** ctor
 105             <p>Note that derived classes still need to add themself as listener to the broadcaster,
 106             as this can't be done in a generic way</p>
 107         */
 108         OWeakListenerAdapter(
 109             const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XWeak >& _rxListener,
 110             const ::com::sun::star::uno::Reference< BROADCASTER >& _rxBroadcaster
 111         );
 112
 113     protected:
 114         inline  ::com::sun::star::uno::Reference< LISTENER > getListener( ) const
 115         {
 116             return  ::com::sun::star::uno::Reference< LISTENER >( OWeakListenerAdapterBase::getListener(), ::com::sun::star::uno::UNO_QUERY );
 117         }
 118
 119         // XEventListener overridables
 120         virtual void SAL_CALL disposing( const ::com::sun::star::lang::EventObject& Source ) throw (::com::sun::star::uno::RuntimeException);
 121
 122     protected:
 123         // OComponentHelper overridables
 124         // to be overridden, again - the derived class should revoke the listener from the broadcaster
 125         virtual void SAL_CALL disposing( ) = 0;
 126     };
 127
 128     //=====================================================================
 129     //= OWeakEventListenerAdapter
 130     //=====================================================================
 131     typedef OWeakListenerAdapter    <   ::com::sun::star::lang::XComponent
 132                                     ,   ::com::sun::star::lang::XEventListener
 133                                     >   OWeakEventListenerAdapter_Base;
 134     /** the most simple listener adapter: for XEventListeners at XComponents
 135     */
 136     class COMPHELPER_DLLPUBLIC OWeakEventListenerAdapter : public OWeakEventListenerAdapter_Base
 137     {
 138     public:
 139         OWeakEventListenerAdapter(
 140             ::com::sun::star::uno::Reference< ::com::sun::star::uno::XWeak > _rxListener,
 141             ::com::sun::star::uno::Reference< ::com::sun::star::lang::XComponent > _rxBroadcaster
 142         );
 143
 144         // nothing to do except an own ctor - the forwarding of the "disposing" is already done
 145         // in the base class
 146
 147     protected:
 148         using OWeakEventListenerAdapter_Base::disposing;
 149         virtual void SAL_CALL disposing( );
 150     };
 151
 152     //=====================================================================
 153     //= OWeakListenerAdapter
 154     //=====================================================================
 155     //---------------------------------------------------------------------
 156     template< class BROADCASTER, class LISTENER >
 157     OWeakListenerAdapter< BROADCASTER, LISTENER >::OWeakListenerAdapter(
 158         const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XWeak >& _rxListener,
 159         const ::com::sun::star::uno::Reference< BROADCASTER >& _rxBroadcaster
 160     )
 161         : ::cppu::WeakComponentImplHelper1< LISTENER >( m_aMutex )
 162         , OWeakListenerAdapterBase( _rxListener, _rxBroadcaster )
 163     {
 164     }
 165
 166     //---------------------------------------------------------------------
 167     template< class BROADCASTER, class LISTENER >
 168     void SAL_CALL OWeakListenerAdapter< BROADCASTER, LISTENER >::disposing( const ::com::sun::star::lang::EventObject& _rSource ) throw (::com::sun::star::uno::RuntimeException)
 169     {
 170         ::com::sun::star::uno::Reference< LISTENER > xListener( getListener() );
 171         if ( xListener.is() )
 172             xListener->disposing( _rSource );
 173     }
 174
 175 //.........................................................................
 176 }   // namespace comphelper
 177 //.........................................................................
 178
 179 #endif // INCLUDED_COMPHELPER_WEAKEVENTLISTENER_HXX
 180
 181
 182 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */