- (void)mouseDown:(NSEvent *)theEvent {
    NSLog(@"mouse down");
}

- (IBAction)doStuff:(id)sender {
    // do stuff here
}

@interface ClickerView : NSControl {
    IBOutlet BoothController *controller;
}
@end

- (void)mouseDown:(NSEvent *)theEvent {
    NSLog(@"mouse down");
    [controller start:self];
}

@protocol MyViewDelegate
    - (void)doStuff:(NSEvent *)event;
@end

@interface MyViewController: NSViewController <MyViewDelegate> {
    // your other ivars etc would go here
}
@end

- (void)doStuff:(NSEvent *)event
{
    NSLog(@"Do stuff delegate was called");
}

@interface MyView: NSView

@property (readwrite, weak) id<MyViewDelegate> delegate;

@end

- (void)mouseDown:(NSEvent *)event
{
    // Do whatever you need to do

    // Check that the delegate has been set, and this it implements the doStuff: message
    if (delegate && [delegate respondsToSelector:@selector(doStuff:)]) {
        [delegate doStuff:event];
    }
 }

...
 MyView *view = [viewController view];
 [view setDelegate:viewController];
 ...