REBOL [ Title: "Calculator" Version: 1.2.2 Date: 17-Jun-2005 ;2-Apr-2001 Author: ["Jeff Kreis" "Allen Kamp" "Carl Sassenrath"] Purpose: {Simple numeric calculator.} Needs: [1.3.0] ] auto-clear: true calculate: does [ if error? try [text-box/text: form do text-box/text][ text-box/text: "Error" text-box/color: red ] auto-clear: true show text-box ] clear-box: does [ clear text-box/text text-box/color: snow auto-clear: false show text-box ] calculator: layout [ style btn btn 40x24 style kc btn red [clear-box] style k= btn [calculate] style k btn [ if auto-clear [clear-box] append text-box/text face/text show text-box ] origin 10 space 4 backeffect base-effect text-box: field "0" 172x24 bold snow right feel none pad 4 across kc "C" keycode [#"C" #"c" page-down] k "(" #"(" k ")" #")" k " / " #"/" return k "7" #"7" k "8" #"8" k "9" #"9" k " * " #"*" return k "4" #"4" k "5" #"5" k "6" #"6" k " - " #"-" return k "1" #"1" k "2" #"2" k "3" #"3" k " + " #"+" return k "0" #"0" k "-" k "." #"." k= green "=" keycode [#"=" #"^m"] return key keycode [#"^(ESC)" #"^q"] [quit] ] view center-face calculator