Timelines & Triggers - Learn SpriteBuilder for iOS Game Development - page 153

Let's use a proper @property this time because you may possibly want to access or
change this value at runtime from other classes. Open Trigger.h and add the @prop-
erty like in Listing 5-6 , as well as the @protocol that defines the method that target
nodes need to implement. Also, add the declaration of the triggerActivatedBy:
method.
Listing 5-6 . Adding the triggerCount property to Trigger.h
#import "CCNode.h"
@protocol TriggerDelegate <NSObject>
-(void) didTriggerWithNode:(CCNode*)activator;
@end
@interface Trigger : CCNode
@property int triggerCount;
-(void) triggerActivatedBy:(CCNode*)activator;
@end
This allows you to run the project without errors, although the trigger itself doesn't work
yet.
Programming the Trigger Class
The Trigger.m implementation will be a tad more complex, but it's also a reusable
class that you may want to use in your own projects. It collects all the trigger and target
nodes upon loading. The Trigger class forwards the trigger collision event to all target
nodes, updates the triggerCount and, if necessary, removes the trigger nodes when
they are no longer needed.
Initializing Trigger and Target Arrays
Start by updating Trigger.m so that it resembles Listing 5-7 .
Listing 5-7 . Trigger implementation initializing trigger and target storage dictionaries
#import "Trigger.h"
static NSMutableDictionary* targetArrays;
static NSMutableDictionary* triggerArrays;