objective c - Getting function key press on NSSearchField without subclassing -

i have simple application has nssearchfield , want know if user presses, example, arrow key. don't want subclass, because want modify values of iboutlets in aplication, , can't in subclass.

edit

the keyup: method override in nssearchfield subclass is:

-(void)keyup:(nsevent*)event {     if ([event keycode]==36){     customers* c= [[customers alloc] init];//customers class have iboulets , methods     [[self window] selectkeyviewfollowingview:self];// change first responder     [c searcht:[self stringvalue]];//here want call method make query , change stringvalues of iboulets     } } 

assign controller delegate of searchfield , implement method:

- (bool)control:(nscontrol *)control textview:(nstextview *)textview docommandbyselector:(sel)command 

you should able receive simple nsresponder selectors such movedown:, moveup:, moveleft:, moveright: correspond arrow keys.