Have a look at the WHO SAID WHAT? part of the notifications tutorial on C4 site.
This part of the notifications tutorial explains how to react to a given object's notification and actually figure out which object just broadcast that notification.
The trick is in building a method that accepts the notification:
-(void)highlightLetter:(NSNotification *)notification {
C4Shape *shape = (C4Shape *)notification.object;
//do stuff to the shape
}
Also, remember that because the method takes a variable you have to include the :
in the name of the method like so:
[self listenFor:@"touchesBegan"
fromObject:greyRect
andRunMethod:@"highlightLetter:"];