Asynchronous xlib/xcb library

Community
1

Hello,

I’m looking for a low-level X library with lwt support. but I did not found anything on opam, even the OCaml-Xlib is not referenced.

Is there any code I can use ?

2

After some exploration in the xcb and ctypes documentation, I’ve managed a working proof of concept and to to recreate the xcb hello world :

xcb publish the underlying file descriptor, which allow to use Lwt for waiting events.

An example is given below :

open Xcb

let () = begin
  match Xcb.connect () with
  | None -> ()
  | Some connexion ->
    Xcb.get_setup connexion
    |> Xcb.setup_roots_iterator
    |> fun iter -> (

      let screen = Xcb.getf iter Xcb.data in
      let width = ((screen |.-> Xcb.width_in_pixel) / 2)
      and height = ((screen |.-> Xcb.height_in_pixel) / 2)
      and depth = ((screen |.-> Xcb.root_depth)) in

      Printf.printf "Creating window (%d, %d) %d\n%!" width height depth;
      match Xcb.create_window
        connexion
        ~depth:(screen |.-> Xcb.root_depth)
        ~parent:(screen |.-> Xcb.root)
        ~x:10
        ~y:10
        ~width
        ~height
        ~border:0
        1
        ~visual:(screen |.-> Xcb.root_visual)
        [
            Back_pixel (screen |.-> Xcb.white_pixel);
            Event_mask ([Exposure; Key_press]);
        ]
      with
      | None -> print_endline "Error"
      | Some id ->
      let _ = Xcb.map_window connexion id in
      let _ = Xcb.flush connexion in
      print_endline "w created";

      let rec p () =  begin
        match%lwt Xcb.poll_event connexion with
        | Key_press -> print_endline "Key_press"; Lwt.return_unit
        | _ -> print_endline "got event"; p()

      end in
      Lwt_main.run (p ())

    )
end

xcb.ml

I need to review the code and provide something more high level, but this is a first step :slight_smile:

3

I think there’s only some old unmaintained bindings to the C libraries which definitely don’t use Lwt.

Anyway, I’m writing a bindings generator that will output bindings with Lwt support… once it’s done. Haven’t done much progress lately. Though I’d be happy to return to it were somebody willing to help.