RosettaCodeData/Task/Draw-a-clock/OCaml/draw-a-clock-2.ml

67 lines
2.1 KiB
OCaml

let pi = 4.0 *. atan 1.0
let angle v max = float v /. max *. 2.0 *. pi
let draw area _ =
let cr = Cairo_lablgtk.create area#misc#window in
let { Gtk.width = width; Gtk.height = height } = area#misc#allocation in
let scale p = float (min width height) *. 0.5 *. p in
let center_x, center_y = float width /. 2.0, float height /. 2.0 in
let invert_y y = float height -. y in
Cairo.set_source_rgb cr 0.8 0.8 0.8;
Cairo.paint cr; (* background *)
Cairo.set_source_rgb cr 1.0 1.0 1.0;
Cairo.arc cr center_x center_y (scale 0.9) 0.0 (2.0 *. pi);
Cairo.set_line_width cr (scale 0.02);
Cairo.stroke cr;
let point a =
let radius = (scale 0.9) in
let x = radius *. sin a
and y = radius *. cos a in
let r = scale 0.04 in
Cairo.arc cr (center_x +. x) (invert_y (center_y +. y)) r 0.0 (2.0 *. pi);
Cairo.fill cr;
in
for i = 0 to pred 12 do
point (angle (i * 30) 360.0)
done;
let tm = Unix.localtime (Unix.gettimeofday ()) in
let sec = angle tm.Unix.tm_sec 60.0 in
let min = angle tm.Unix.tm_min 60.0 in
let hour = angle (tm.Unix.tm_hour * 60 + tm.Unix.tm_min) (12.0 *. 60.0) in
Cairo.set_line_cap cr Cairo.LINE_CAP_ROUND;
let hand t radius lwidth (r, g, b) =
let x = radius *. sin t
and y = radius *. cos t in
Cairo.set_line_width cr (scale lwidth);
Cairo.move_to cr center_x center_y;
Cairo.line_to cr (center_x +. x) (invert_y (center_y +. y));
Cairo.set_source_rgb cr r g b;
Cairo.stroke cr;
in
hand sec (scale 0.9) 0.04 (0.0, 0.5, 1.0);
hand min (scale 0.7) 0.06 (0.0, 0.0, 0.5);
hand hour (scale 0.6) 0.09 (1.0, 0.0, 0.5);
true
let animate area =
ignore (GMain.Timeout.add 200 (fun () ->
GtkBase.Widget.queue_draw area#as_widget; true))
let () =
let w = GWindow.window ~title:"OCaml GtkCairo Clock" () in
ignore (w#connect#destroy GMain.quit);
let f = GBin.frame ~shadow_type:`IN ~packing:w#add () in
let area = GMisc.drawing_area ~width:200 ~height:200 ~packing:f#add () in
area#misc#set_double_buffered true;
ignore (area#event#connect#expose (draw area));
animate area;
w#show ();
GMain.main ()