#import @class ResourceDocument, Resource; @interface ResourceDataSource : NSObject { IBOutlet NSOutlineView *outlineView; IBOutlet NSWindow *window; IBOutlet ResourceDocument *document; NSMutableArray *resources; } - (NSWindow *)window; - (NSArray *)resources; - (void)setResources:(NSMutableArray *)newResources; - (void)addResource:(Resource *)resource; - (void)removeResource:(Resource *)resource; // accessors - (Resource *)resourceNamed:(NSString *)name ofType:(NSString *)type; @end