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(* $Id: calc.ml,v 1.12 2003/02/20 06:47:47 garrigue Exp $ *)
(* A simple calculator ported from LablTk to LablGtk *)
let mem_string ~char s =
try
for i = 0 to String.length s -1 do
if s.[i] = char then raise Exit
done; false
with Exit -> true
let ops = ['+',(+.); '-',(-.); '*',( *.); '/',(/.)]
(* The abstract calculator class. Does not use Gtk *)
class virtual calc = object (calc)
val mutable x = 0.0
val mutable op = None
val mutable displaying = true
method virtual set : string -> unit
method virtual get : string
method virtual quit : unit -> unit
method insert s = calc#set (calc#get ^ s)
method get_float = float_of_string (calc#get)
initializer calc#set "0"
method command s =
if s <> "" then match s.[0] with
'0'..'9' ->
if displaying then (calc#set ""; displaying <- false);
calc#insert s
| '.' ->
if displaying then
(calc#set "0."; displaying <- false)
else
if not (mem_string ~char:'.' calc#get) then calc#insert s
| '+'|'-'|'*'|'/' as c ->
displaying <- true;
begin match op with
None ->
x <- calc#get_float;
op <- Some (List.assoc c ops)
| Some f ->
x <- f x (calc#get_float);
op <- Some (List.assoc c ops);
calc#set (string_of_float x)
end
| '='|'\n'|'\r' ->
displaying <- true;
begin match op with
None -> ()
| Some f ->
x <- f x (calc#get_float);
op <- None;
calc#set (string_of_float x)
end
| 'q' -> calc#quit ()
| _ -> ()
end
(* Buttons for the calculator *)
let m =
[|[|"7";"8";"9";"+"|];
[|"4";"5";"6";"-"|];
[|"1";"2";"3";"*"|];
[|"0";".";"=";"/"|]|]
(* The physical calculator. Inherits from the abstract one *)
open GMain
class calculator ?packing ?show () =
let table = GPack.table ~rows:5 ~columns:4 ~homogeneous:true ~show:false () in
object (calc)
inherit calc
val label =
let frame = GBin.frame ~shadow_type:`IN ()
~packing:(table#attach ~left:0 ~top:0 ~right:4 ~expand:`BOTH) in
let evbox = GBin.event_box ~packing:frame#add () in
evbox#misc#set_style evbox#misc#style#copy;
evbox#misc#style#set_bg [`NORMAL,`WHITE];
GMisc.label ~justify:`RIGHT ~xalign:0.95 ~packing:evbox#add ()
val table = table
method set = label#set_text
method get = label#text
method quit = Main.quit
initializer
for i = 0 to 3 do for j = 0 to 3 do
let button =
GButton.button ~label:(" " ^ m.(i).(j) ^ " ")
~packing:(table#attach ~top:(i+1) ~left:j ~expand:`BOTH) () in
button#connect#clicked ~callback:(fun () -> calc#command m.(i).(j));
done done;
ignore (GObj.pack_return table ~packing ~show)
end
(* Finally start everything *)
let w = GWindow.window ()
let applet = new calculator ~packing: w#add ()
let _ =
w#connect#destroy ~callback: Main.quit;
w#event#connect#key_press
~callback:(fun ev -> applet#command (GdkEvent.Key.string ev); true);
w#show ();
Main.main ()
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