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open Pdfutil
(* Padding with blank pages. *)
let insert_after pos page pages =
let before, after = cleave pages pos in
before @ [page] @ after
(* Insert many. *)
let rec insert_after_many pages = function
| [] -> pages
| (pos, page)::more ->
let pages' = insert_after pos page pages in
insert_after_many pages' (map (fun (p, pa) -> p + 1, pa) more)
(* For each pagenum in the range, increment the count by padsize, and carry on. e.g
insert_after_many_changes 1 0 [2] [1; 2; 3] --> [(1, 1); (2, 2); (3, 4)] *)
let rec insert_after_many_changes isbefore padsize offset range = function
[] -> []
| h::t ->
let item = (h, h + offset + if isbefore && mem h range then 1 else 0) in
if mem h range then
item::insert_after_many_changes isbefore padsize (offset + padsize) range t
else
item::insert_after_many_changes isbefore padsize offset range t
let pad_with_pdf (range : int list) (pdf : Pdf.t) (isbefore : bool) (padfile : Pdf.t) =
let range = sort compare (setify range) in
let merged =
Pdfmerge.merge_pdfs
false false ["a"; "b"] [pdf; padfile] [ilist 1 (Pdfpage.endpage pdf); ilist 1 (Pdfpage.endpage padfile)]
in
let original_pages, padpages =
cleave (Pdfpage.pages_of_pagetree merged) (Pdfpage.endpage pdf)
in
let newpages =
map
(fun (pagenum, page) ->
if mem pagenum range then
(if isbefore then padpages @ [page] else [page] @ padpages)
else
[page])
(combine (indx original_pages) original_pages)
in
(* FIXME Provide ~changes here? *)
Pdfpage.change_pages false merged (flatten newpages)
let pad padwith range pdf isbefore =
match padwith with
Some padfile -> pad_with_pdf range pdf isbefore padfile
| None ->
let i = if isbefore then 1 else 0 in
let pages = Pdfpage.pages_of_pagetree pdf in
let blankpages =
map
(fun n ->
{Pdfpage.content = [];
Pdfpage.mediabox = (select (n + i) pages).Pdfpage.mediabox;
Pdfpage.resources = Pdf.Dictionary [];
Pdfpage.rotate = (select (n + i) pages).Pdfpage.rotate;
Pdfpage.rest = Pdf.remove_dict_entry ((select (n + i) pages).Pdfpage.rest) "/Annots"})
range
in
let pages' = insert_after_many pages (combine range blankpages) in
let changes =
insert_after_many_changes
isbefore 1 0 (map (fun x -> x + i) range) (ilist 1 (length pages))
in
Pdfpage.change_pages ~changes true pdf pages'
let padafter ?padwith range pdf =
let isinpdf n = mem n (ilist 1 (Pdfpage.endpage pdf)) in
if not (fold_left ( && ) true (map isinpdf range)) then
raise (Failure "padafter: range contains pages not present in pdf");
pad padwith range pdf false
let padbefore ?padwith range pdf =
let isinpdf n = mem n (ilist 1 (Pdfpage.endpage pdf)) in
if not (fold_left ( && ) true (map isinpdf range)) then
raise (Failure "padbefore: range contains pages not present in pdf");
pad padwith (map pred range) pdf true
let padmultiple n pdf =
let neg, n = n < 0, if n < 0 then -n else n in
let pages = Pdfpage.pages_of_pagetree pdf in
let len = length pages in
let pages_to_add = if len / n * n = len then 0 else n - (len mod n) in
if pages_to_add > 0 then
let blankpages =
many
{Pdfpage.content = [];
Pdfpage.mediabox = (select len pages).Pdfpage.mediabox;
Pdfpage.resources = Pdf.Dictionary [];
Pdfpage.rotate = (select len pages).Pdfpage.rotate;
Pdfpage.rest = Pdf.Dictionary []}
pages_to_add
in
let changes = map (fun x -> (x, x)) (ilist 1 (length pages)) in
Pdfpage.change_pages ~changes true pdf (if neg then blankpages @ pages else pages @ blankpages)
else
pdf
|
