From 71adabd103fd862e54254e6b639e8bf9cc1aef31 Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Mon, 2 Dec 2024 18:39:29 +0000
Subject: [PATCH] Scaffolding for dot leaders in TOC

---
 cpdfcommand.ml | 14 ++++++++++----
 cpdftoc.ml     |  9 +++++++--
 cpdftoc.mli    |  2 +-
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index d8e1236..c6d3c0d 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -571,7 +571,8 @@ type args =
    mutable rast_jpeg_quality : int;
    mutable rast_downsample : bool;
    mutable replace_stream_with : string;
-   mutable output_unit : Pdfunits.t}
+   mutable output_unit : Pdfunits.t;
+   mutable dot_leader : bool}
 
 let args =
   {op = None;
@@ -720,7 +721,8 @@ let args =
    rast_jpeg_quality = 75;
    rast_downsample = false;
    replace_stream_with = "";
-   output_unit = Pdfunits.PdfPoint}
+   output_unit = Pdfunits.PdfPoint;
+   dot_leader = false}
 
 (* Do not reset original_filename or cpdflin or was_encrypted or
 was_decrypted_with_owner or recrypt or producer or creator or path_to_* or
@@ -855,7 +857,8 @@ let reset_arguments () =
   args.rast_jpeg_quality <- 75;
   args.rast_downsample <- false;
   args.replace_stream_with <- "";
-  args.output_unit <- Pdfunits.PdfPoint
+  args.output_unit <- Pdfunits.PdfPoint;
+  args.dot_leader <- false
 
 (* Prefer a) the one given with -cpdflin b) a local cpdflin, c) otherwise assume
 installed at a system place *)
@@ -2919,6 +2922,9 @@ let specs =
    ("-toc-no-bookmark",
      Arg.Unit settocnobookmark,
      " Don't add the table of contents to the bookmarks");
+   ("-toc-dot-leader",
+     Arg.Unit (fun () -> args.dot_leader <- true),
+     " Add a dot leader to TOC entries");
    ("-typeset",
      Arg.String settypeset,
      " Typeset a text file as a PDF");
@@ -4802,7 +4808,7 @@ let go () =
       let cpdffont = embed_font () in
       let pdf =
         Cpdftoc.typeset_table_of_contents
-          ~font:cpdffont ~fontsize:args.fontsize ~title:args.toc_title ~bookmark:args.toc_bookmark pdf
+          ~font:cpdffont ~fontsize:args.fontsize ~title:args.toc_title ~bookmark:args.toc_bookmark ~dotleader:args.dot_leader pdf
       in
         write_pdf false pdf
   | Some (Typeset filename) ->
diff --git a/cpdftoc.ml b/cpdftoc.ml
index 63204ca..7af48cb 100644
--- a/cpdftoc.ml
+++ b/cpdftoc.ml
@@ -94,11 +94,16 @@ let used pdf fastrefnums labels title marks =
       marks;
     codepoints
 
+(* Fill the space with a small space, maybe some dots, then maybe a final tiny space *)
+(* TODO Test to make sure a title shortened with dots does not gain any leader dots through this mechanism *)
+let make_dots space =
+  [Cpdftype.HGlue space]
+
 (* Typeset a table of contents with given font, font size and title. Mediabox
    (and CropBox) copied from first page of existing PDF. Margin of 10% inside
    CropBox. Font size of title twice body font size. Null page labels added for
    TOC, others bumped up and so preserved. *)
-let typeset_table_of_contents ~font ~fontsize ~title ~bookmark pdf =
+let typeset_table_of_contents ~font ~fontsize ~title ~bookmark ~dotleader pdf =
   Hashtbl.clear width_table_cache;
   let marks = Pdfmarks.read_bookmarks pdf in
   if marks = [] then (Pdfe.log "No bookmarks, not making table of contents\n"; pdf) else
@@ -150,7 +155,7 @@ let typeset_table_of_contents ~font ~fontsize ~title ~bookmark pdf =
            [Cpdftype.BeginDest mark.Pdfmarks.target;
             Cpdftype.HGlue indent]
            @ textruns @
-           [Cpdftype.HGlue space]
+           (if dotleader then make_dots space else [Cpdftype.HGlue space])
            @ labelruns @
            [Cpdftype.EndDest;
             Cpdftype.NewLine])
diff --git a/cpdftoc.mli b/cpdftoc.mli
index afe71bd..bc8509a 100644
--- a/cpdftoc.mli
+++ b/cpdftoc.mli
@@ -1,4 +1,4 @@
 (** Table of contents *)
 
 (** Typeset a table of contents and prepend to the document. *)
-val typeset_table_of_contents : font:Cpdfembed.cpdffont -> fontsize:float -> title:string -> bookmark:bool -> Pdf.t -> Pdf.t
+val typeset_table_of_contents : font:Cpdfembed.cpdffont -> fontsize:float -> title:string -> bookmark:bool -> dotleader:bool -> Pdf.t -> Pdf.t