ocaml/otherlibs/labltk/frx/frx_font.ml

51 lines
2.1 KiB
OCaml

(***********************************************************************)
(* *)
(* MLTk, Tcl/Tk interface of OCaml *)
(* *)
(* Francois Rouaix, Francois Pessaux, Jun Furuse and Pierre Weis *)
(* projet Cristal, INRIA Rocquencourt *)
(* Jacques Garrigue, Kyoto University RIMS *)
(* *)
(* Copyright 2002 Institut National de Recherche en Informatique et *)
(* en Automatique and Kyoto University. All rights reserved. *)
(* This file is distributed under the terms of the GNU Library *)
(* General Public License, with the special exception on linking *)
(* described in file LICENSE found in the OCaml source tree. *)
(* *)
(***********************************************************************)
open Camltk
open Widget
let version = "$Id$"
(*
* Finding fonts. Inspired by code in Ical by Sanjay Ghemawat.
* Possibly bogus because some families use "i" for italic where others
* use "o".
* wght: bold, medium
* slant: i, o, r
* pxlsz: 8, 10, ...
*)
module StringSet = Set.Make(struct type t = string let compare = compare end)
let available_fonts = ref (StringSet.empty)
let get_canvas =
Frx_misc.autodef (fun () -> Canvas.create Widget.default_toplevel [])
let find fmly wght slant pxlsz =
let fontspec =
"-*-"^fmly^"-"^wght^"-"^slant^"-normal-*-"^string_of_int pxlsz^"-*-*-*-*-*-iso8859-1" in
if StringSet.mem fontspec !available_fonts then fontspec
else
let c = get_canvas() in
try
let tag = Canvas.create_text c (Pixels 0) (Pixels 0)
[Text "foo"; Font fontspec] in
Canvas.delete c [tag];
available_fonts := StringSet.add fontspec !available_fonts;
fontspec
with
_ -> raise (Invalid_argument fontspec)