PS/Tk

PS/Tk provides an interface to the Tk toolkit, and is an effective tool for creating graphical interfaces. A detailed guide to using Tk from Scheme is in progress.

  1. PS/Tk
    1. Examples
      1. Hello World
      2. Simple Dialog
    2. Tips on Using PS/Tk
    3. Authors
    4. License
    5. Requirements
    6. Version History

Examples

Several examples can be found in the svn repository for this egg.

Hello World

(require-extension pstk)

(tk-start)

(tk/pack 
  (tk 'create-widget 'button 'text: "Hello" 
      'command: (lambda () (display "Hello world") (newline)))
  'padx: 20 'pady: 20)
(tk-event-loop)

Simple Dialog

(require-extension pstk)

(define (celsius->fahrenheit item)
  (let ((number (string->number item)))
    (if (number? number)
      (+ (* number 9/5) 32)
      0.0)))

(tk-start)
(tk/wm 'title tk "Celsius to Fahrenheit")

(let* ((celsius (tk 'create-widget 'entry))
       (label (tk 'create-widget 'label))
       (button (tk 'create-widget 'button
		   'text: 'Calculate
		   'command: (lambda () 
			       (label 'configure 
				      'text: (number->string (celsius->fahrenheit (celsius 'get))))))))
  ; layout widgets in a grid
  (tk/grid celsius 'column: 2 'row: 1 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid label 'column: 2 'row: 2 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid button 'column: 2 'row: 3 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "celsius") 
	   'column: 3 'row: 1 'sticky: 'w 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "is") 
	   'column: 1 'row: 2 'sticky: 'e 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "fahrenheit") 
	   'column: 3 'row: 2 'sticky: 'w 'padx: 5 'pady: 5)

  (tk-event-loop))

Tips on Using PS/Tk

(tk-start "wish85")
(tk/message-box 'title: "starting program" 'message: "Press ENTER" 'type: 'ok)
(tk-wm title tk "PROGRAM") 
etc
(handle-exceptions
  exn
  (tk-end)  ; make sure tk is closed in event of any error
  ; begin program
  (tk-start)
 ; rest of  gui setup
 )
(set! process (lambda (#!rest rest)
    (receive (a b c d) (apply process* rest)
    (values a b c))))

to your .scm file like this:

(require-extension pstk)

;; http://bugs.call-cc.org/ticket/765
;; broken posix/process function under Windows 7 (MingW)
(set! process (lambda (#!rest rest)
    (receive (a b c d) (apply process* rest)
    (values a b c))))
(tk-start "tclsh85")
(tk/pack 
  (tk 'create-widget 'button 'text: "Hello" 
      'command: (lambda () (display "Hello world") (newline)))
  'padx: 20 'pady: 20)
(tk-event-loop)
     (tk-init-string
       (string-intersperse
                          '("package require Tk"
                            "fconfigure stdin -encoding utf-8"
                            "fconfigure stdout -encoding utf-8"
                            "if {[package version tile] != \"\"} {"
                            "    package require tile"
                            "}"

Alternatively, add the following in your script:

(tk-start)
(tk-eval "fconfigure stdin -encoding ascii")
(tk-eval "fconfigure stdout -encoding ascii")

Authors

Kenneth A Dickey, Nils M Holm and Wolf-Dieter Busch created the initial versions of pstk. This port to Chicken, plus some additions, is by Peter Lane.

License

Public Domain.

Requirements

Requires an installation of tcltk or tclkit.

Version History