Create Your Characters: Game Engine, Image Actors, and Behaviors - Beginning iOS6 Games Development - page 131

NSMutableSet* sorted = [actorClassToActorSet valueForKey:[[actor class] description]];
[sorted addObject:actor];
}
[actorsToBeAdded removeAllObjects];
}
-(void)doRemoveActors{
for (Actor* actor in actorsToBeRemoved){
UIView* view = [[actor representation] getViewForActor:actor In:self];
[view removeFromSuperview];
NSMutableSet* sorted = [actorClassToActorSet valueForKey:[[actor class] description]];
[sorted removeObject:actor];
[actors removeObject:actor];
}
[actorsToBeRemoved removeAllObjects];
doAddActors iterates through all actors in the NSMutableSet actorsToBeAdded and adds
NSMutableSet actors. Additionally, a UIView for each actor is retrieved from the
actorsView . The property representation
NSObject that conforms to the protocol Representation (as defined in Actor.h in Listing 6-9).
NSMutableSet sorted that corresponds to the actor's class in
NSMutableDictionary actorClassToActorSet . The actor is then added to the NSMutableSet
NSMutableDictionary actorClassToActorSet . The last step in doAddActors is to remove all of the
actors from the set actorsToBeRemoved .
In the preceding listing, we see the task doRemoveActors that parallels the task doAddActors . In
doRemoveActors , each actor in the NSMutableSet actorsToBeRemoved has its associated UIView
removed from its super-view and is removed from the corresponding NSMutableSet sorted. Each
actor is also removed from the NSMutableSet actors. Finally, the NSMutableSet actorsToBeRemoved is
cleared of all actors by calling removeAllObjects .
Adding and Removing Actors
To add or remove an actor from the game, we call addActor or removeActor , respectively, as shown
in Listing 6-6.
Listing 6-6. GameController.m (addActor and removeActor)
-(void)addActor:(Actor*)actor{
[actor setAdded:YES];
[actorsToBeAdded addObject:actor];
}
-(void)removeActor:(Actor*)actor{
[actor setRemoved:YES];
[actorsToBeRemoved addObject:actor];
}