REBOL [ Title: "Desk Calculator" Date: 4-Oct-2004 Version: 1.3.0 File: %desk-calc.r Author: "Ryan S. Cole" Purpose: "A tool for simple calculations." Comment: "Standard function calculator." Email: %ryan--skurunner--com library: [ level: 'intermediate platform: 'all type: 'tool domain: [math GUI] tested-under: none support: none license: none see-also: none ] ] acc: ; Accumulator op: ; Selected operation mem: ; Memory storage err: none ; Error state reg: [] ; Register stack ; For working with the displayed number... cur-str: does [any [reg/1 acc form 0]] cur-num: does [to-decimal cur-str] cur-set: func [val] [ either not either op [reg/2][reg/1] [insert reg form val] [reg/1: form val] ] ; Updates the screen... display: does [ if not find lcd/text: copy cur-str "." [append lcd/text "."] err-flag/font/color: either err [yellow][gray] mem-flag/font/color: either mem [green][gray] show [lcd err-flag mem-flag] ] ; Does the equation... solve: does [ if not reg/2 [insert reg reg/1] acc: none if op [err: error? try [acc: form do reform [reg/2 op 'to-decimal reg/1]]] reg: copy [] op: none ] ; Handles keypresses press: func [key] [ err: no if find ".0123456789" key [ if not either op [reg/2][reg/1] [insert reg copy ""] if all ["." = key find reg/1 key] [exit] either all [reg/1 = "0" key <> "."] [reg/1: copy key] [append reg/1 key] ] if find "+-*/" key [ if reg/2 [solve] if not reg/1 [insert reg cur-str] op: key ] switch key [ "C" [acc: op: none reg: copy []] "E" [remove reg op: acc: none] "±" [cur-set negate cur-num] "MC" [mem: none] "MR" [cur-set any [mem 0]] "M+" [mem: add any [mem 0] cur-num] "M-" [mem: subtract any [mem 0] cur-num] "pi" [cur-set pi] "=" [solve] ] ] ; Construct the screen... view layout compose [ backdrop effect [gradient 0x1 85.155.205 80.130.180] origin 10x10 space 0x0 pad 0x10 across style text text 15x20 bold gray mem-flag: text "M" err-flag: text "E" pad 5x0 space 5x5 lcd: field "0." silver 170x20 right bold feel none return style k (pick [btn button] link?) 30x20 [press face/text display] k #"C" "C" k "MC" k #"7" "7" k #"8" "8" k #"9" "9" k #"/" "/" return k #"E" "E" k "MR" k #"4" "4" k #"5" "5" k #"6" "6" k #"*" "*" return k #"p" "pi" k "M+" k #"1" "1" k #"2" "2" k #"3" "3" k #"+" "+" return k #"i" "±" k "M-" k #"0" "0" k #"." "." k #"=" "=" k #"-" "-" keycode #"^M" [press "=" display] ]