GUI component interaction: Difference between revisions

</lang>

=={{header|Echolisp}}==

<lang scheme>

(require 'interface)

;; helper new button with text

(define (ui-add-button text)

(define b (ui-create-element "button" '((type "button"))))

(ui-set-html b text)

(ui-add b))

(define (panel )

(ui-clear)

(info-text "My rosetta application" "blue")

;; input field (checked for numeric)

(define f-input (ui-create-element "input" '((type number))))

(ui-set-value f-input 0)

(ui-add f-input)

(ui-on-focus f-input (lambda(e) (info-text "")))

;; Increment button

(define btn-inc (ui-add-button "Increment"))

(define (increment elem)

(define val (ui-get-numvalue f-input))

(if val ;; checked legal numeric

(ui-set-value f-input (1+ val))

(info-text "Need a number" "red")))

(ui-on-click btn-inc increment)

(ui-add btn-inc)

(define btn-random (ui-add-button "Random"))

(define (set-random elem)

(when (confirm "Really random?")

(ui-set-value f-input (random-prime 1000000))))

(ui-on-click btn-random set-random)

(ui-focus btn-inc)

(stdout-hide #t)

(stdin-hide #t)) ;; end panel

(panel)