UIPasscodeField is a segmented group of text fields for entering fixed-length passcode. This is similar to the SpringBoard passcode entry and is in fact used there.
All appearance settings must be done only once, because frame is being overdrawn.
Delegates of UIPasscodeField must conform to the following informal protocol:
@protocol UIPasscodeFieldDelegate @optional -(void)passcodeFieldDidAcceptEntry:(UIPasscodeField*)field; -(BOOL)passcodeField:(UIPasscodeField*)field shouldInsertText:(NSString*)text; -(void)passcodeFieldTextDidChange:(UIPasscodeField*)field; @end