From 9e1cf6f78e2b8615b5cfbb870e0c0d07c98ff79f Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Wed, 25 Sep 2024 15:12:58 +0100
Subject: [PATCH] Scaffolding for -elt-info

---
 cpdfcommand.ml      |  3 +++
 cpdfdraw.ml         | 19 ++++++++++++++-----
 cpdfdraw.mli        |  4 ++++
 cpdfdrawcontrol.ml  | 14 ++++++++++++++
 cpdfdrawcontrol.mli |  3 +++
 cpdfmanual.tex      |  2 ++
 6 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 07be95e..762971e 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -2841,7 +2841,10 @@ let specs =
    ("-artifact", Arg.Unit (fun _ -> Cpdfdrawcontrol.artifact ()), " Begin an artifact");
    ("-end-artifact", Arg.Unit (fun _ -> Cpdfdrawcontrol.endartifact ()), "End an artifact");
    ("-no-auto-artifacts", Arg.Unit (fun _ -> Cpdfdrawcontrol.autoartifacts false), " Don't mark untagged content as artifacts");
+   ("-eltinfo", Arg.String (fun s -> Cpdfdrawcontrol.eltinfo s), " Add element information");
+   ("-end-eltinfo", Arg.String (fun s -> Cpdfdrawcontrol.endeltinfo s), " Erase element information");
    ("-namespace", Arg.String (fun s -> Cpdfdrawcontrol.addnamespace (expand_namespace s)), " Set the structure tree namespace");
+   ("-rolemap", Arg.String (fun s -> Cpdfdrawcontrol.setrolemap s), " Set a role map");
    ("-rect", Arg.String Cpdfdrawcontrol.addrect, " Draw rectangle");
    ("-to", Arg.String Cpdfdrawcontrol.addto, " Move to");
    ("-line", Arg.String Cpdfdrawcontrol.addline, " Add line to");
diff --git a/cpdfdraw.ml b/cpdfdraw.ml
index 214ea97..e8cdc78 100644
--- a/cpdfdraw.ml
+++ b/cpdfdraw.ml
@@ -5,6 +5,8 @@ let do_add_artifacts = ref true
 
 let do_auto_tag = ref true
 
+let rolemap = ref ""
+
 type colspec =
    NoCol
  | RGB of float * float * float
@@ -65,6 +67,8 @@ type drawops =
   | BeginArtifact
   | EndArtifact
   | Namespace of string
+  | EltInfo of string * string
+  | EndEltInfo of string
 
 (*let rec string_of_drawop = function
   | Qq o -> "Qq (" ^ string_of_drawops o ^ ")"
@@ -721,11 +725,16 @@ let write_structure_tree pdf st =
       | [] -> []
       | ns -> [("/Namespaces", Pdf.Array (map (function (_, objnum) -> Pdf.Indirect objnum) ns))]
     in
-    Pdf.Dictionary
-      (namespaces @
-        [("/Type", Pdf.Name "/StructTreeRoot");
-         ("/ParentTree", Pdf.Indirect (Pdf.addobj pdf (Pdftree.build_name_tree true pdf parentmap))); 
-         ("/K", Pdf.Array items)])
+    let rolemap =
+      match !rolemap with
+      | "" -> []
+      | s -> [("/RoleMap", Pdfread.parse_single_object ("<<" ^ s ^ ">>"))]
+    in
+      Pdf.Dictionary
+        (rolemap @ namespaces @
+          [("/Type", Pdf.Name "/StructTreeRoot");
+           ("/ParentTree", Pdf.Indirect (Pdf.addobj pdf (Pdftree.build_name_tree true pdf parentmap))); 
+           ("/K", Pdf.Array items)])
   in
     Pdf.addobj_given_num pdf (struct_tree_root, st);
     Pdf.replace_chain pdf ["/Root"] ("/StructTreeRoot", (Pdf.Indirect struct_tree_root))
diff --git a/cpdfdraw.mli b/cpdfdraw.mli
index 78aae37..bfcf18e 100644
--- a/cpdfdraw.mli
+++ b/cpdfdraw.mli
@@ -60,11 +60,15 @@ type drawops =
   | BeginArtifact
   | EndArtifact
   | Namespace of string
+  | EltInfo of string * string
+  | EndEltInfo of string
 
 val do_add_artifacts : bool ref
 
 val do_auto_tag : bool ref
 
+val rolemap : string ref
+
 (** Calling [draw fast underneath filename bates batespad range pdf drawops] draws on
     top of all the pages in the range. *)
 val draw : struct_tree:bool ->
diff --git a/cpdfdrawcontrol.ml b/cpdfdrawcontrol.ml
index 9562d32..dc7527d 100644
--- a/cpdfdrawcontrol.ml
+++ b/cpdfdrawcontrol.ml
@@ -123,6 +123,20 @@ let endartifact () =
 let addnamespace s =
   addop (Cpdfdraw.Namespace s)
 
+let eltinfo s =
+  let k, v =
+    match String.split_on_char '=' s with
+    | [h; t] -> (h, t)
+    | _ -> error "Bad -eltinfo format"
+  in
+    addop (Cpdfdraw.EltInfo (k, v))
+
+let endeltinfo s =
+  addop (Cpdfdraw.EndEltInfo s)
+
+let setrolemap s =
+  Cpdfdraw.rolemap := s
+
 let addrect s =
   let x, y, w, h = Cpdfcoord.parse_rectangle (Pdf.empty ()) s in
     addop (Cpdfdraw.Rect (x, y, w, h))
diff --git a/cpdfdrawcontrol.mli b/cpdfdrawcontrol.mli
index 92bcfe9..e2338ff 100644
--- a/cpdfdrawcontrol.mli
+++ b/cpdfdrawcontrol.mli
@@ -20,7 +20,10 @@ val addstag : string -> unit
 val endtag : unit -> unit
 val endstag : unit -> unit
 val autotags : bool -> unit
+val eltinfo : string -> unit
+val endeltinfo : string -> unit
 val addnamespace : string -> unit
+val setrolemap : string -> unit
 val artifact : unit -> unit
 val endartifact : unit -> unit
 val autoartifacts : bool -> unit
diff --git a/cpdfmanual.tex b/cpdfmanual.tex
index bf55e8e..ad551eb 100644
--- a/cpdfmanual.tex
+++ b/cpdfmanual.tex
@@ -1,3 +1,5 @@
+%Document -rolemap
+%Document -eltinfo X=, -end-eltinfo X
 %Document -stretch
 %Document -redact
 %Document ?x0 y0 x1 y1 rectangle specifications