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open Js_of_ocaml
let textarea (textbox : Dom_html.textAreaElement Js.t) : unit =
let rec loop s acc (i, pos') =
try
let pos = String.index_from s pos' '\n' in
loop s ((i, (pos', pos)) :: acc) (succ i, succ pos)
with _ -> List.rev ((i, (pos', String.length s)) :: acc)
in
let rec find (l : (int * (int * int)) list) c =
match l with
| [] -> assert false
| (i, (lo, up)) :: _ when up >= c -> c, i, lo, up
| (_, (_lo, _up)) :: rem -> find rem c
in
let v = textbox##.value in
let pos =
let c1 = textbox##.selectionStart and c2 = textbox##.selectionEnd in
if Js.Opt.test (Js.Opt.return c1) && Js.Opt.test (Js.Opt.return c2)
then
let l = loop (Js.to_string v) [] (0, 0) in
Some (find l c1, find l c2)
else None
in
let f =
match pos with
| None -> fun _ -> true
| Some ((_c1, line1, _lo1, _up1), (_c2, line2, _lo2, _up2)) ->
fun l -> l >= line1 + 1 && l <= line2 + 1
in
let v = Ocp_indent.indent (Js.to_string v) f in
textbox##.value := Js.string v;
match pos with
| Some ((c1, line1, _lo1, up1), (c2, line2, _lo2, up2)) ->
let l = loop v [] (0, 0) in
let lo1'', up1'' = List.assoc line1 l in
let lo2'', up2'' = List.assoc line2 l in
let n1 = max (c1 + up1'' - up1) lo1'' in
let n2 = max (c2 + up2'' - up2) lo2'' in
let () = (Obj.magic textbox)##setSelectionRange n1 n2 in
textbox##focus;
()
| None -> ()
|
