ltk
Posted: Tue Dec 25, 2018 4:09 am
Hello there,
I cannot figure out how to update variable s when clicking button "Sum"
I cannot figure out how to update variable s when clicking button "Sum"
Code: Select all
(in-package :ltk)
(defun string-to-number (n)
(car (list (read-from-string n))))
(defun sum (a b)
(+ (string-to-number a) (string-to-number b)))
(defvar s)
(setq s 0)
(defun ltksum()
(with-ltk ()
(let* ((bar (make-instance 'frame))
#-:tk84
(e1 (make-instance 'entry :master bar))
(e2 (make-instance 'entry :master bar))
(b4 (make-instance 'button
:master bar
:text "Sum"
:command (lambda ()
(setf s (sum (text e1) (text e2))))))
(l (make-instance 'label
:master bar
:text s)))
(pack bar)
(pack e1 :side :left)
(pack e2 :side :left)
(pack b4 :side :left)
(pack l :side :left)
)))