:: com :: sun :: star :: uno ::
- Usage Restrictions
- Deprecation Info
- Aggregation will no longer be supported as a high-level concept of UNO.
You may still have the option to implement an UNO object consisting of
several single objects in your specific programming language, though this
depends on your programming language.
- Objects which implement this interface can become aggregates of
That means if an object "A" aggregates "B", "A" can provide all
or some of the interfaces of "B". Whenever the method
is called on either of the objects, the call will be forwarded
to object "A". Object "A" now can determine whether to use the
interfaces of "A" or "B" or neither. Actually, any number of
aggregates can be used, even nested ones (aggregated objects which are
delegators by themselves).
The following rules are to be observed:
- All calls to XInterface::acquire()
which are made before the delegator was set (using the method
setDelegator()) must not be taken back
(using the method XInterface::release())
before the delegation is removed by calling
- The constructor of a delegator has to increment its
own reference count by calling its method
before it sets itself to any aggregate using the method
setDelegator(). After that
call it has to reset its own reference count without the
destructor getting called.
- The destructor of a delegator has to reset the delegator in
its aggregated objects by calling their method
NULL before it releases its reference to
its aggregated objects.
- Developers Guide
- WritingUNO - Core Interfaces to Implement
- WritingUNO - XAggregation
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