This commit is contained in:
John Whitington 2020-02-26 18:54:23 +01:00
parent 78908569be
commit 4d088e6702
1 changed files with 36 additions and 17 deletions

View File

@ -3566,15 +3566,15 @@ let write_json output pdf =
(* 1. Get list of indirects of all OCGs from the /OCProperties, and their textual names
* 2. Calculate a change list to coalesce them
* 3. Make the changes in /Properties lists of pages / form xobjects. Anywhere else?
* 4. Remove the old ones by making null everywhere else in the document. *)
* 3. Remove any changed ones from the /OCGs and /Order in /OCProperties
* 4. Do the changes to all indirect references in the whole pdf *)
(*FIXME Pre-existing nulls - what to do? *)
let ocg_coalesce pdf =
let number_name_pairs =
match Pdf.lookup_direct pdf "/OCProperties" (Pdf.catalog_of_pdf pdf) with
None -> []
| Some d ->
match Pdf.lookup_direct pdf "/OCGs" d with
match Pdf.lookup_direct pdf "/OCProperties" (Pdf.catalog_of_pdf pdf) with
None -> pdf
| Some ocpdict ->
let number_name_pairs =
match Pdf.lookup_direct pdf "/OCGs" ocpdict with
Some (Pdf.Array ocgs) ->
begin let numbers =
map (function Pdf.Indirect i -> i | _ -> failwith "Malformed /OCG entry") ocgs
@ -3598,16 +3598,35 @@ let ocg_coalesce pdf =
combine numbers names
end
| _ -> failwith "Malformed or missing /OCGs"
in
iter (fun (num, name) -> Printf.printf "%i = %s\n" num name) number_name_pairs;
let changes =
let cf (_, name) (_, name') = compare name name' in
let sets = collate cf (List.stable_sort cf number_name_pairs) in
flatten (option_map (function [] -> None | (hnum, _)::t -> Some (map (function (tnum, _) -> (tnum, hnum)) t)) sets)
in
Printf.printf "\nChanges are:\n";
List.iter (fun (f, t) -> Printf.printf "%i -> %i\n" f t) changes;
pdf
in
iter (fun (num, name) -> Printf.printf "%i = %s\n" num name) number_name_pairs;
let changes =
let cf (_, name) (_, name') = compare name name' in
let sets = collate cf (List.stable_sort cf number_name_pairs) in
flatten (option_map (function [] -> None | (hnum, _)::t -> Some (map (function (tnum, _) -> (tnum, hnum)) t)) sets)
in
Printf.printf "\nChanges are:\n";
List.iter (fun (f, t) -> Printf.printf "%i -> %i\n" f t) changes;
let new_ocproperties =
(* FIXME: Instead, look for order / ocgs inside "/D" !! - one more layer of indirection *)
let remove_from_array key nums dict =
match Pdf.lookup_direct pdf key dict with
| Some (Pdf.Array elts) ->
let elts' = option_map (function Pdf.Indirect i -> if mem i nums then None else Some (Pdf.Indirect i) | _ -> None) elts in
Pdf.add_dict_entry dict key (Pdf.Array elts')
| _ -> dict
in
let nums = map fst changes in
Printf.printf "\nto remove:\n";
List.iter (Printf.printf "%i ") nums;
remove_from_array "/OCGs" nums (remove_from_array "/Order" nums ocpdict)
in
flprint (Pdfwrite.string_of_pdf new_ocproperties);
let ocp_objnum = Pdf.addobj pdf new_ocproperties in
let new_catalog = Pdf.add_dict_entry (Pdf.catalog_of_pdf pdf) "/OCProperties" (Pdf.Indirect ocp_objnum) in
pdf.Pdf.trailerdict <- Pdf.add_dict_entry pdf.Pdf.trailerdict "/Root" new_catalog;
Pdf.objselfmap (Pdf.renumber_object_parsed pdf (hashtable_of_dictionary changes)) pdf;
pdf
(* Main function *)
let go () =