quicktime.app.spaces
Interface DynamicCollection
- All Superinterfaces:
- Collection
- All Known Subinterfaces:
- QTDisplaySpace, Space
- public interface DynamicCollection
- extends Collection
The DynamicCollection uses the Protocol class to enable
the application to dynamically type members on a collection
by collection basis. Dynamic collections use the protocol to
test to see if an object is appropriate before it is accepted
as a candidate for membership of the collection.
This enables an application to tighten the restrictions on membership
on a case by case basis. For example, the DirectGroup is a DynamicCollection,
of which the fundamental requirement is that the member implement the
QTDrawable interface. However if a particular application wanted to ensure that
for a particular group only movies were in the collection, the application could
get the Protocol object for that particular DirectGroup and add the MoviePlayer
class to the collection of class objects that make up the Protocol. Consequent
uses of that direct group would ensure that the object being added was both a
QTDrawable and MoviePlayer before the object was added. The application (having
specified this protocol) can then make certain assumptions about the type of object
that is a member of the collection.
Changing a protocol after a member has been added to the collection will not mean that
existing members are removed if they do not match the new protocol, thus protocols should
only be specified when the collection is empty.
- See Also:
Protocol
Method Summary |
Protocol |
getProtocol()
Returns the Protocol class that is used to when testing
an object's appropriateness for membership of a collection. |
getProtocol
public Protocol getProtocol()
- Returns the Protocol class that is used to when testing
an object's appropriateness for membership of a collection.
- Returns:
- a Protocol object.