include/unotools/sharedunocomponent.hxx

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  19
  20 #ifndef INCLUDED_UNOTOOLS_SHAREDUNOCOMPONENT_HXX
  21 #define INCLUDED_UNOTOOLS_SHAREDUNOCOMPONENT_HXX
  22
  23 #include <config_options.h>
  24 #include <unotools/unotoolsdllapi.h>
  25 #include <com/sun/star/uno/Reference.hxx>
  26 #include <rtl/ref.hxx>
  27 #include <memory>
  28
  29 namespace com::sun::star {
  30     namespace lang {
  31         class XComponent;
  32     }
  33 }
  34
  35 namespace utl
  36 {
  37
  38     //= DisposableComponent
  39
  40     /** is a class which controls lifetime of a UNO component via ->XComponent::dispose
  41
  42         You'll usually never use this class directly, but only as parameter for a
  43         ->SharedUNOComponent class.
  44     */
  45     class UNOTOOLS_DLLPUBLIC DisposableComponent
  46     {
  47         css::uno::Reference< css::lang::XComponent >  m_xComponent;
  48
  49     public:
  50         /** constructs a ->DisposableComponent instance
  51
  52         @param _rxComponent
  53             the component whose life time should be controlled by the instance. Must not be <NULL/>.
  54         */
  55         DisposableComponent( const css::uno::Reference< css::uno::XInterface >& _rxComponent );
  56
  57         /** disposes the component represented by the instance
  58
  59             The component is queried for ->XComponent(which <em>must</em> be supported),
  60             and ->XComponent::dispose is invoked. A failure of this invocation (e.g. a thrown
  61             exception) is silenced in release builds, and reported in debug builds.
  62         */
  63         ~DisposableComponent();
  64
  65     private:
  66         DisposableComponent( const DisposableComponent& ) = delete;
  67         DisposableComponent& operator=( const DisposableComponent& ) = delete;
  68     };
  69
  70     //= CloseableComponent
  71
  72     class CloseableComponentImpl;
  73     /** is a class which controls lifetime of a UNO component via ->XCloseable::close
  74
  75         You'll usually never use this class directly, but only as parameter for a
  76         ->SharedUNOComponent class.
  77     */
  78     class UNLESS_MERGELIBS_MORE(UNOTOOLS_DLLPUBLIC) CloseableComponent
  79     {
  80     private:
  81         /** Our IMPL class.
  82         */
  83         ::rtl::Reference< CloseableComponentImpl >  m_pImpl;
  84
  85     public:
  86         /** constructs a ->CloseableComponent instance
  87
  88         @param _rxComponent
  89             the component whose life time should be controlled by the instance. Must not be <NULL/>.
  90         */
  91         CloseableComponent( const css::uno::Reference< css::uno::XInterface >& _rxComponent );
  92
  93         /** destroys resources associated with this instance, and disposes the component
  94
  95             The component is queried for ->XCloseable (which <em>must</em> be supported),
  96             and ->XCloseable::close is invoked, with delivering the ownership.
  97             If the invocation fails with a ->CloseVetoException, this is ignored, since in
  98             this case the vetoing instance took the ownership.
  99
 100             Any other failure will be reported in a debug version via assertion mechanisms,
 101             and silenced in release builds.
 102         */
 103         ~CloseableComponent();
 104
 105     private:
 106         CloseableComponent( const CloseableComponent& ) = delete;
 107         CloseableComponent& operator=( const CloseableComponent& ) = delete;
 108     };
 109
 110     //= SharedUNOComponent
 111
 112     /** is a helper class for sharing ownership of a UNO component
 113
 114         If you need to share a UNO component, which normally needs a dedicated owner,
 115         and is lifetime controlled by an explicit disposal action (not necessarily ->XComponent::dispose,
 116         but <em>any</em> explicit method call, after which the object is considered
 117         to be disposed), between different classes, ->SharedUNOComponent is what you need.
 118
 119         Instead of passing around a <code>Reference&lt; XFoo &gt;</code>, and bothering
 120         with ownership and disposal, you just use a <code>SharedUNOComponent&lt; XFoo &gt;</code>.
 121         This instance can be passed around, including copying, and in nearly all respects behaves
 122         like the original <code>Reference&lt; XFoo &gt;</code>. However, when the last
 123         ->SharedUNOComponent referencing a certain <code>Reference&lt; XFoo &gt;</code> dies, it
 124         will automatically get rid of the object held by this reference.
 125
 126     @param INTERFACE
 127         the UNO interface type as which the component should be held
 128
 129     @param COMPONENT_HOLDER
 130         a class which can be used to represent and dispose a UNO component.
 131         The class must support (maybe explicit only) construction from a
 132         <code>Reference&lt; INTERFACE &gt;</code>, and destruction. Upon destruction,
 133         the class must dispose (by any suitable means) the component instance it was
 134         constructed with.
 135     */
 136     template < class INTERFACE, class COMPONENT = DisposableComponent >
 137     class SharedUNOComponent
 138     {
 139     private:
 140         typedef COMPONENT                           Component;
 141
 142     private:
 143         std::shared_ptr<Component>                            m_xComponent;
 144         css::uno::Reference< INTERFACE >            m_xTypedComponent;
 145
 146     public:
 147         enum AssignmentMode
 148         {
 149             TakeOwnership,
 150             NoTakeOwnership
 151         };
 152
 153     public:
 154         SharedUNOComponent()
 155         {
 156         }
 157
 158         explicit SharedUNOComponent( const css::uno::Reference< INTERFACE >& _rxComponent, AssignmentMode eMode = TakeOwnership )
 159         {
 160             reset( _rxComponent, eMode );
 161         }
 162
 163         SharedUNOComponent( const css::uno::BaseReference & _rRef, css::uno::UnoReference_QueryThrow _queryThrow )
 164         {
 165             set( _rRef, _queryThrow );
 166         }
 167
 168 //        SharedUNOComponent& operator=( const css::uno::Reference< INTERFACE >& _rxComponent );
 169         // This operator is intentionally not implemented. There is no canonic ownership after this operator
 170         // would have been applied: Should the SharedUNOComponent have the ownership of the component,
 171         // or shouldn't it? Hard to guess, and probably wrong in 50 percent of all cases, anyway. So,
 172         // instead of tempting clients of this class to use such a dangerous operator, we do
 173         // not offer it at all. If you need to assign a Reference< INTERFACE > to your SharedUNOComponent,
 174         // use the ->reset method.
 175
 176         /** assigns a new component, and releases the old one
 177         */
 178         void reset( const css::uno::Reference< INTERFACE >& _rxComponent, AssignmentMode _eMode = TakeOwnership );
 179
 180         inline bool set( const css::uno::BaseReference& _rRef, css::uno::UnoReference_Query _query );
 181
 182         inline void set( const css::uno::BaseReference & _rRef, css::uno::UnoReference_QueryThrow _queryThrow );
 183
 184         inline void set( const css::uno::Reference< INTERFACE >& _rRef, css::uno::UnoReference_SetThrow _setThrow );
 185         inline void set( const SharedUNOComponent& _rComp, css::uno::UnoReference_SetThrow _setThrow );
 186
 187         INTERFACE* SAL_CALL operator->() const;
 188
 189         operator const css::uno::Reference< INTERFACE >&() const
 190         {
 191             return m_xTypedComponent;
 192         }
 193
 194         const css::uno::Reference< INTERFACE >& getTyped() const
 195         {
 196             return m_xTypedComponent;
 197         }
 198
 199         bool is() const
 200         {
 201             return m_xTypedComponent.is();
 202         }
 203
 204         void clear()
 205         {
 206             m_xComponent.reset();
 207             m_xTypedComponent.clear();
 208         }
 209     };
 210
 211     template < class INTERFACE, class COMPONENT >
 212     INTERFACE* SAL_CALL SharedUNOComponent< INTERFACE, COMPONENT >::operator->() const
 213     {
 214         return m_xTypedComponent.operator->();
 215     }
 216
 217     // assignments
 218     template < class INTERFACE, class COMPONENT >
 219     void SharedUNOComponent< INTERFACE, COMPONENT >::reset( const css::uno::Reference< INTERFACE >& _rxComponent, AssignmentMode _eMode )
 220     {
 221         m_xComponent.reset(_eMode == TakeOwnership ? new COMPONENT( _rxComponent ) : nullptr);
 222         m_xTypedComponent = _rxComponent;
 223     }
 224
 225     // comparison operators
 226
 227     template < class INTERFACE, class COMPONENT >
 228     bool operator==( const SharedUNOComponent< INTERFACE, COMPONENT >& _rLHS, const css::uno::Reference< INTERFACE >& _rRHS )
 229     {
 230         return _rLHS.getTyped() == _rRHS;
 231     }
 232
 233     template < class INTERFACE, class COMPONENT >
 234     inline css::uno::Any SAL_CALL makeAny( const SharedUNOComponent< INTERFACE, COMPONENT >& value )
 235     {
 236         return css::uno::Any( value.getTyped() );
 237     }
 238
 239     template < class INTERFACE, class COMPONENT >
 240     void SharedUNOComponent< INTERFACE, COMPONENT >::set( const css::uno::BaseReference & _rRef, css::uno::UnoReference_QueryThrow _queryThrow )
 241     {
 242         reset( css::uno::Reference< INTERFACE >( _rRef, _queryThrow ), TakeOwnership );
 243     }
 244
 245     template < class INTERFACE, class COMPONENT >
 246     void SharedUNOComponent< INTERFACE, COMPONENT >::set( const css::uno::Reference< INTERFACE >& _rRef, css::uno::UnoReference_SetThrow _setThrow )
 247     {
 248         reset( css::uno::Reference< INTERFACE >( _rRef, _setThrow ), TakeOwnership );
 249     }
 250
 251     template < class INTERFACE, class COMPONENT >
 252     void SharedUNOComponent< INTERFACE, COMPONENT >::set( const SharedUNOComponent& _rComp, css::uno::UnoReference_SetThrow _setThrow )
 253     {
 254         *this = _rComp;
 255         // provoke an exception in case the component is NULL
 256         m_xTypedComponent.set( m_xTypedComponent, _setThrow );
 257     }
 258
 259     template < class INTERFACE, class COMPONENT >
 260     bool SharedUNOComponent< INTERFACE, COMPONENT >::set( const css::uno::BaseReference& _rRef, css::uno::UnoReference_Query _query )
 261     {
 262         reset( css::uno::Reference< INTERFACE >( _rRef, _query ) );
 263         return is();
 264     }
 265
 266 }   // namespace utl
 267
 268 #endif // INCLUDED_UNOTOOLS_SHAREDUNOCOMPONENT_HXX
 269
 270 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */