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PS/Tk provides an interface to the Tk toolkit, and is an effective tool for creating graphical interfaces.


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

Simple Dialog

(require-extension pstk)

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

(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)


Using Tk

This section contains some simple use cases for parts of the Tk toolkit.

Simple Widgets


A 'button' displays a label or image and can be clicked to invoke its command.

(tk 'create-widget 'button 
    'text: "Label" 
    'command: (lambda () "action"))


A 'label' is intended to display a single line of text.

(tk 'create-widget 'label 
    'text: "Label")

The labelframe is a container widget, displaying a title and line around the widgets within it.

The following sequence packs a label within a label frame, which is then displayed in the top window.

(define tk (tk-start))
(define labelframe (tk 'create-widget 'labelframe 'text: "Frame"))
(tk/pack (tk 'create-widget 'label 
             'text: "around label") 
         'in: labelframe)
(tk/pack labelframe)

The scale widget displays a slider which takes a value along a range. The user can drag the slider to a desired value, and the programmer can get or set the value.

(define tk (tk-start))
(define scale (tk 'create-widget 'scale 
                              'label: "Scale widget"
                              'from: -100
                              'to: 100
                              'length: 300
                              'orient: 'horizontal
                              'showvalue: #t
                              'tickinterval: 20))
(tk/pack scale)

The value of the scale can be retrieved (as a string) using:

> (scale 'get)

The value of the scale can be set using:

> (scale 'set 39)

Decorations: Relief and Borders

An example illustrating the ranges of border/relief type.

(require-extension pstk)
(require-extension srfi-42)

(tk/wm 'title tk "PS/Tk Example: Label relief")
(tk 'configure 'borderwidth: 10)

(do-ec (: relief '("raised" "sunken" "flat" "ridge" "groove" "solid"))
         (tk 'create-widget 'label 'text: relief
             'relief: relief
             'bd: 2    ; width of the relief
             'padx: 10 ; inner padding, between label and its relief
         'side: 'left 'padx: 4))



By default, the program tclsh85 is called, but an alternative program may be provided as an optional argument to (tk-start). For example, to instead use wish84 begin the program with (tk-start "wish84").

Under windows, there is a problem with keyboard input. Currently, the fix is to show a dialog box which is dismissed by pressing 'Enter' (not clicking!) directly after starting tk.

(tk-start "wish85")
(tk/message-box 'title: "starting program" 'message: "Press ENTER" 'type: 'ok)
(tk-wm title tk "PROGRAM") 


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.


Public Domain.


Requires an installation of tcltk.

Version History