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©Copyright 1996 Rogue Wave Software
typedef unsigned short RWClassID;
typedef RWCollectable* (*RWuserCreator)(); #include <rw/factory.h> RWFactory* theFactory;
Class RWFactory can create an instance of an RWCollectable object, given a class ID. It does this by maintaining a table of class IDs and associated "creator functions." A creator function has prototype:
RWCollectable* aCreatorFunction();
This function should create an instance of a particular class. For a given RWClassID tag, the appropriate function is selected, invoked and the resultant pointer returned. Because any object created this way is created off the heap, you are responsible for deleting it when done.
There is a one-of-a-kind global RWFactory which can be accessed using getRWFactory. It is guaranteed to have creator functions in it for all of the classes referenced by your program. See also the section in the User's Guide about RWFactory.
None
#include <rw/factory.h>
#include <rw/rwbag.h>
#include <rw/colldate.h>
#include <rw/rstream.h>
main(){
// Create new RWBag off the heap, using Class ID __RWBAG.
RWBag* b = (RWBag*)getRWFactory ()->create(__RWBAG);
b->insert( new RWCollectableDate ); // Insert today's date
// ...
b->clearAndDestroy(); // Cleanup: first delete members,
delete b; // then the bag itself
}
RWFactory();
Construct an RWFactory.
RWBoolean operator<=(const RWFactory& h);
Returns TRUE if self is a subset of h, that is, every element of self has a counterpart in h which isEqual. This operator is included to fix an inconsistency in the C++ language. It is not explicitly present unless you are compiling with an implementation of the Standard C++ Library. It would normally be inherited from RWSet
Note: If you inherit from RWFactory in the presence of the Standard C++ Library, we recommend that you override this operator and explicitly forward the call. Overload resolution in C++ will choose the Standard Library provided global operators over inherited class members. These global definitions are not appropriate for set-like partial orderings.
void addFunction(RWuserCreator uc, RWClassID id);
Adds to the RWFactory the global function pointed to by uc, which creates an instance of an object with RWClassID id.
void addFunction(RWuserCreator uc, RWClassID id, RWStringID sid);
Adds to the RWFactory the global function pointed to by uc, which creates an instance of an object with RWClassID id and RWStringID sid.
RWCollectable* create(RWClassID id) const;
Allocates a new instance of the class with RWClassID id off the heap and returns a pointer to it. Returns nil if id does not exist. Because this instance is allocated off the heap, you are responsible for deleting it when done.
RWCollectable* create(RWString sid) const;
Allocates a new instance of the class with RWStringID sid off the heap and returns a pointer to it. Returns nil if sid does not exist. Because this instance is allocated off the heap, you are responsible for deleting it when done.
RWuserCreator getFunction(RWClassID id) const;
Returns from the RWFactory a pointer to the global function associated with RWClassID id. Returns nil if id does not exist.
RWuserCreator getFunction(RWStringID sid) const;
Returns from the RWFactory a pointer to the global function associated with RWStringID sid. Returns nil if sid does not exist.
void removeFunction(RWClassID id);
Removes from the RWFactory the global function associated with RWClassID id. If id does not exist in the factory, no action is taken.
void removeFunction(RWStringID sid);
Removes from the RWFactory the global function associated with RWStringID sid. If sid does not exist in the factory, no action is taken.
RWStringID stringID(RWClassID id) const;
Looks up the RWStringID associated with id and returns it. If there is no such association, returns RWStringID("NoID").
RWClassID classID(RWStringID) const;
Looks up the RWClassID associated with sid and returns it. If there is no such association, returns __RWUNKNOWN.
