cpdf-source/cpdfattach.ml

227 lines
10 KiB
OCaml

open Pdfutil
open Pdfio
open Cpdferror
(* Attaching files *)
let attach_file ?memory keepversion topage pdf file =
let data =
match memory with
Some data -> data
| None ->
let ch = open_in_bin file in
let len = in_channel_length ch in
let stream = mkbytes len in
let i = input_of_channel ch in
setinit i stream 0 len;
close_in ch;
stream
in
let filestream =
Pdf.Stream
(ref (Pdf.Dictionary
[("/Length", Pdf.Integer (bytes_size data));
("/Type", Pdf.Name "/EmbeddedFile");
("/Params",
Pdf.Dictionary
[("/Size", Pdf.Integer (bytes_size data));
("/CheckSum", Pdf.String (Digest.string (string_of_bytes data)))
])],
Pdf.Got data))
in
let filestream_num = Pdf.addobj pdf filestream in
let basename = Pdftext.pdfdocstring_of_utf8 (Filename.basename file) in
let filespec =
Pdf.Dictionary
[("/EF", Pdf.Dictionary ["/F", Pdf.Indirect filestream_num]);
("/F", Pdf.String basename);
("/Type", Pdf.Name "/Filespec");
("/Desc", Pdf.String "");
("/UF", Pdf.String basename)]
in
match topage with
| None ->
(* Look up /Names and /EmbeddedFiles and /Names. *)
let rootdict = Pdf.lookup_obj pdf pdf.Pdf.root in
let namedict =
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> Pdf.Dictionary []
| Some namedict -> namedict
in
let embeddednamedict =
match Pdf.lookup_direct pdf "/EmbeddedFiles" namedict with
| None -> Pdf.Dictionary []
| Some embeddednamedict -> embeddednamedict
in
let elts =
match Pdf.lookup_direct pdf "/Names" embeddednamedict with
| Some (Pdf.Array elts) -> elts
| _ -> []
in
let filespecobj = Pdf.addobj pdf filespec in
let names' = Pdf.Array (elts @ [Pdf.String basename; Pdf.Indirect filespecobj]) in
let embeddednamedict' = Pdf.add_dict_entry embeddednamedict "/Names" names' in
let namedict' = Pdf.add_dict_entry namedict "/EmbeddedFiles" embeddednamedict' in
let rootdict' = Pdf.add_dict_entry rootdict "/Names" namedict' in
let rootnum = Pdf.addobj pdf rootdict' in
{pdf with
Pdf.minor = if keepversion then pdf.Pdf.minor else max pdf.Pdf.minor 4;
Pdf.root = rootnum;
Pdf.trailerdict =
Pdf.add_dict_entry
pdf.Pdf.trailerdict "/Root" (Pdf.Indirect rootnum)}
| Some pagenumber ->
let pages = Pdfpage.pages_of_pagetree pdf in
if pagenumber < 0 || pagenumber > length pages then error "attach_file: Page not found" else
let page = select pagenumber pages in
let annots =
match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> []
in
let rect =
let minx, miny, maxx, maxy = Pdf.parse_rectangle page.Pdfpage.mediabox in
Pdf.Array [Pdf.Real 18.; Pdf.Real (maxy -. 45.); Pdf.Real 45.; Pdf.Real (maxy -. 18.)]
in
let filespecobj = Pdf.addobj pdf filespec in
let annot =
Pdf.Dictionary
[("/FS", Pdf.Indirect filespecobj);
("/Subtype", Pdf.Name "/FileAttachment");
("/Contents", Pdf.String basename);
("/Rect", rect)]
in
let annots' = Pdf.Array (annot::annots) in
let page' =
{page with Pdfpage.rest = Pdf.add_dict_entry page.Pdfpage.rest "/Annots" annots'}
in
let pages' = replace_number pagenumber page' pages in
let pdf = Pdfpage.change_pages true pdf pages' in
{pdf with
Pdf.minor = if keepversion then pdf.Pdf.minor else max pdf.Pdf.minor 4}
type attachment =
{name : string;
pagenumber : int;
data : unit -> Pdfio.bytes}
let list_attached_files pdf =
let toplevel =
match Pdf.lookup_direct pdf "/Root" pdf.Pdf.trailerdict with
| None -> []
| Some rootdict ->
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> []
| Some namedict ->
match Pdf.lookup_direct pdf "/EmbeddedFiles" namedict with
| Some nametree ->
map
(function (x, ef) ->
match Pdf.lookup_direct pdf "/EF" ef with
| Some ((Pdf.Dictionary _) as d) ->
begin match Pdf.lookup_direct pdf "/F" d with
| Some stream ->
{name = x;
pagenumber = 0;
data =
(fun () ->
try
Pdf.getstream stream;
Pdfcodec.decode_pdfstream pdf stream;
match stream with
Pdf.Stream {contents = (_, Pdf.Got data)} -> data
| _ -> raise Not_found
with
_ -> raise (Pdf.PDFError "could not retreive attachment data"))}
| None -> raise (Pdf.PDFError "/F not found")
end
| _ -> raise (Pdf.PDFError "/EF not found"))
(option_map
(function (Pdf.String s, ef) -> Some (s, ef) | _ -> None)
(Pdf.contents_of_nametree pdf nametree))
| _ -> []
in let pagelevel =
let pages = Pdfpage.pages_of_pagetree pdf in
flatten
(map2
(fun page pagenumber ->
option_map
(function annot ->
match Pdf.lookup_direct pdf "/Subtype" annot with
| Some (Pdf.Name "/FileAttachment") ->
(match Pdf.lookup_direct pdf "/Contents" annot with
| Some (Pdf.String s) ->
begin match Pdf.lookup_direct pdf "/FS" annot with
| Some ((Pdf.Dictionary _) as d) ->
(*Printf.eprintf "%s\n%!" (Pdfwrite.string_of_pdf d);*)
begin match Pdf.lookup_direct pdf "/EF" d with
| Some ((Pdf.Dictionary _) as d) ->
begin match Pdf.lookup_direct pdf "/F" d with
| Some stream ->
Some
{name = s;
pagenumber = pagenumber;
data =
(fun () ->
try
Pdf.getstream stream;
Pdfcodec.decode_pdfstream pdf stream;
match stream with
Pdf.Stream {contents = (_, Pdf.Got data)} -> data
| _ -> raise Not_found
with
_ -> raise (Pdf.PDFError "could not retreive attachment data"))}
| _ -> raise (Pdf.PDFError "no /F found in attachment")
end
| _ ->
Some
{name = s;
pagenumber = pagenumber;
data = (fun () -> raise (Pdf.PDFError "no attachment data"))}
end
| _ -> None
end
| _ -> None)
| _ -> None)
(match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> []))
pages
(indx pages))
in
toplevel @ pagelevel
(* \section{Remove Attached files} *)
let remove_attached_files_on_pages pdf =
let remove_from_page page =
{page with Pdfpage.rest =
Pdf.add_dict_entry page.Pdfpage.rest "/Annots"
(Pdf.Array
(option_map
(function annot ->
match Pdf.lookup_direct pdf "/Subtype" annot with
| Some (Pdf.Name "/FileAttachment") -> None
| _ -> Some annot)
(match Pdf.lookup_direct pdf "/Annots" page.Pdfpage.rest with
| Some (Pdf.Array annots) -> annots
| _ -> [])))}
in
Pdfpage.change_pages true pdf (map remove_from_page (Pdfpage.pages_of_pagetree pdf))
let remove_attached_files pdf =
let pdf = remove_attached_files_on_pages pdf in
match Pdf.lookup_direct pdf "/Root" pdf.Pdf.trailerdict with
| None -> pdf
| Some rootdict ->
match Pdf.lookup_direct pdf "/Names" rootdict with
| None -> pdf
| Some namedict ->
let namedict' = Pdf.remove_dict_entry namedict "/EmbeddedFiles" in
let rootdict' = Pdf.add_dict_entry rootdict "/Names" namedict' in
let rootdict'num = Pdf.addobj pdf rootdict' in
{pdf with
Pdf.root =
rootdict'num;
Pdf.trailerdict =
Pdf.add_dict_entry pdf.Pdf.trailerdict "/Root" (Pdf.Indirect rootdict'num)}