F <-> C converter with a close button

with_close.lsp

(let ((w (.window *app*))
     (root (.init (UIView.)))
     (input  (.init (UITextField.)))
     (output  (.init (UITextField.)))
     (convert-f-c (UIButton/buttonWithType: UIButtonTypeSystem))
     (convert-c-f (UIButton/buttonWithType: UIButtonTypeSystem))
     (close (UIButton/buttonWithType: UIButtonTypeSystem)))

 (.frame= root '((10 200) (220 200)))
 (.backgroundColor= root (UIColor/lightGrayColor))

 (.frame= input '((10 10) (200 44)))
 (.placeholder= input "Degrees F or C")

 (.frame= output '((10 100) (200 44)))

 (.frame= convert-f-c '((10 60) (100 44)))
 (.backgroundColor= convert-f-c (UIColor/lightGrayColor))
 (.setTitle:forState: convert-f-c "F -> C" UIControlStateNormal)
 (.setTitleColor:forState: convert-f-c (UIColor/blackColor) UIControlStateNormal)
 (.when convert-f-c UIControlEventTouchUpInside
        (lambda ()
          (let ((f (float (.text input)))
                (c (* (/ 5.0 9.0) (- f 32))))
            (.text= output (str c)))))

 (.frame= convert-c-f '((110 60) (100 44)))
 (.backgroundColor= convert-c-f (UIColor/lightGrayColor))
 (.setTitle:forState: convert-c-f "C -> F" UIControlStateNormal)
 (.setTitleColor:forState: convert-c-f (UIColor/blackColor) UIControlStateNormal)
 (.when convert-c-f UIControlEventTouchUpInside
        (lambda ()
          (let ((c (float (.text input)))
                (f (+ (* (/ 9.0 5.0) c) 32)))
            (.text= output (str f)))))

 (.frame= close '((10 150) (200 44)))
 (.setTitle:forState: close "Close" UIControlStateNormal)
 (.when close UIControlEventTouchUpInside
        (lambda ()
           (.removeFromSuperview root)))

 (.addSubview root input)
 (.addSubview root convert-f-c)
 (.addSubview root convert-c-f)
 (.addSubview root output)
 (.addSubview root close)
 (.addSubview w root))