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.
Description
Objects which implement this interface can become aggregates of
a delegator.
That means if an object "A" aggregates "B", "A" can provide all
or some of the interfaces of "B". Whenever the method
XInterface::queryInterface()
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
xAggregation->setDelegator(NULL).
The constructor of a delegator has to increment its
own reference count by calling its method
XInterface::acquire()
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
setDelegator() with
NULL before it releases its reference to
its aggregated objects.
specifies the object which handles the calls to
XInterface::queryInterface().
If xDelegator is NULL, the delegator is
removed and thus the object becomes its own delegator and has
to handle calls to the method
XInterface::queryInterface()
itself.
is similar to XInterface::queryInterface(),
but it is to be processed directly without being forwarded to the
delegator. @
This method is only called from within an implementation of
XInterface::queryInterface()
or XAggregation::queryAggregation(). This method
is to be called by the delegator if it does not implement the
interface itself. An object which got aggregated cannot depend
on getting its own interface when it calls the method
XInterface::queryInterface().
