From c122df5dc592b0d4f9364f728ad31dfd80248608 Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Tue, 8 Jun 2021 16:58:35 +0100
Subject: [PATCH] ocg list split

---
 cpdf.ml  | 12 +++++++++---
 cpdf.mli |  2 ++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/cpdf.ml b/cpdf.ml
index 07d7c3f..7a3ec84 100644
--- a/cpdf.ml
+++ b/cpdf.ml
@@ -4459,8 +4459,9 @@ let ocg_coalesce pdf =
         pdf.Pdf.root <- new_catalog;
         Pdf.objselfmap (Pdf.renumber_object_parsed pdf (hashtable_of_dictionary changes)) pdf
 
-let ocg_list pdf =
-  match Pdf.lookup_direct pdf "/OCProperties" (Pdf.catalog_of_pdf pdf) with
+let ocg_get_list pdf =
+  let l = ref [] in
+  begin match Pdf.lookup_direct pdf "/OCProperties" (Pdf.catalog_of_pdf pdf) with
     None -> ()
   | Some ocpdict ->
       match Pdf.lookup_direct pdf "/OCGs" ocpdict with
@@ -4469,10 +4470,15 @@ let ocg_list pdf =
             (function
                Pdf.Indirect i ->
                  (match Pdf.lookup_direct pdf "/Name" (Pdf.lookup_obj pdf i) with
-                    Some (Pdf.String s) -> Printf.printf "%s\n" s | _ -> ())
+                    Some (Pdf.String s) -> l := s::!l | _ -> ())
              | _ -> ())
             elts
       | _ -> ()
+  end;
+  rev !l
+
+let ocg_list pdf =
+  List.iter (Printf.printf "%s\n") (ocg_get_list pdf)
 
 let ocg_rename f t pdf =
   Pdf.objselfmap
diff --git a/cpdf.mli b/cpdf.mli
index 32be12c..d7e4d0a 100644
--- a/cpdf.mli
+++ b/cpdf.mli
@@ -459,6 +459,8 @@ val append_page_content : string -> bool -> bool -> int list -> Pdf.t -> Pdf.t
 
 val ocg_coalesce : Pdf.t -> unit
 
+val ocg_get_list : Pdf.t -> string list
+
 val ocg_list : Pdf.t -> unit
 
 val ocg_rename : string -> string -> Pdf.t -> unit