UIResponder.swift

extension UIResponder {
    public class let keyboardWillShowNotification: NSNotification.Name
    public class let keyboardDidShowNotification: NSNotification.Name
    public class let keyboardWillHideNotification: NSNotification.Name
    public class let keyboardDidHideNotification: NSNotification.Name
    public class let keyboardWillChangeFrameNotification: NSNotification.Name
    public class let keyboardDidChangeFrameNotification: NSNotification.Name

    public class let keyboardFrameBeginUserInfoKey: String // NSValue of CGRect
    public class let keyboardFrameEndUserInfoKey: String // NSValue of CGRect
    public class let keyboardAnimationDurationUserInfoKey: String // NSNumber of double
    public class let keyboardAnimationCurveUserInfoKey: String // NSNumber of NSUInteger (UIViewAnimationCurve)
    public class let keyboardIsLocalUserInfoKey: String // NSNumber of BOOL
}