From: Martin Mares <mj@ucw.cz>
Date: Tue, 5 Jun 2018 18:57:07 +0000 (+0200)
Subject: Added a module for maintaining PDF meta-data
X-Git-Tag: v1.99~1^2~28
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=a3ee069a5a1457959f80d849c1bd67d13643b180;p=ucwmac.git

Added a module for maintaining PDF meta-data

It works only LuaTeX, but defines stubs with other engines.
---

diff --git a/test-ref.tex b/test-ref.tex
index 6dd327a..9967773 100644
--- a/test-ref.tex
+++ b/test-ref.tex
@@ -1,15 +1,20 @@
 \input ucwmac.tex
-\input ucw-ref.tex
 \input ucw-ofs.tex
+\input ucw-ref.tex
+\input ucw-pdfmeta.tex
 
 % \clickablefalse
 
+\pdfmetainfo{Author}{A. U. Thor}
+\pdfmetainfo{Title}{TeX Caput Regni}
+
 \newcount\chapcount
 \chapcount=0
 \optdef\chapter#1{
 	\vfill\eject
 	\advance\chapcount by 1
 	\addid{chap}{\the\chapcount}
+	\pdfmetaoutline{\the\chapcount}{\currentid}{#1}
 	\leftline{\the\chapcount. #1}
 	\medskip
 }
diff --git a/ucw-pdfmeta.lua b/ucw-pdfmeta.lua
new file mode 100644
index 0000000..80e743a
--- /dev/null
+++ b/ucw-pdfmeta.lua
@@ -0,0 +1,203 @@
+-- A library for writing PDF metadata
+
+luatexbase.provides_module {
+	name	= 'pdfmeta',
+	version	= '0.0',
+	author	= 'Martin Mareš',
+}
+
+pdfmeta = { }
+
+-- Debugging function for dumping a table
+
+local function do_dump_table(t, key, depth)
+	local tmp = string.rep("  ", depth)
+	if key then
+		tmp = tmp .. key .. ": "
+	end
+	if type(t) == "table" then
+		texio.write(tmp .. "{\n")
+		for k, v in pairs(t) do
+			do_dump_table(v, k, depth+1)
+		end
+		tmp = string.rep("  ", depth) .. "}"
+	elseif type(t) == "number" then
+		tmp = tmp .. tostring(t)
+	elseif type(t) == "string" then
+		tmp = tmp .. string.format("%q", t)
+	else
+		tmp = tmp .. "???"
+	end
+	texio.write(tmp .. "\n")
+end
+
+local function dump_table(t)
+	do_dump_table(t, nil, 0)
+end
+
+-- PDF metadata can be encoded either in an ancient PDFEncoding, which covers
+-- only a small subset of Unicode characters, or in UTF-16-BE. We use the latter
+-- for anything outside basic ASCII. It is tempting to use "lualibs-unicode"
+-- for the conversion, but alas, it is too broken.
+
+local function pdf_string(s)
+	local u16 = {}
+	local str = {}
+	local strok = true
+	table.insert(u16, "<feff")
+	for x in string.utfvalues(s) do
+		if x >= 0x20 and x < 0x7f and x ~= 0x28 and x ~= 0x29 and x ~= 0x5c then
+			if x == 0x28 or x == 0x29 or x == 0x5c then
+				table.insert(str, "\\" .. string.char(x))
+			else
+				table.insert(str, string.char(x))
+			end
+		else
+			strok = false
+		end
+		if x < 0x10000 then
+			table.insert(u16, string.format("%04x", x))
+		else
+			local y = x - 0x10000
+			local h = y/1024 + 0xd800
+			local l = y%1024 + 0xdc00
+			table.insert(u16, string.format("%04x%04x", h, l))
+		end
+	end
+
+	if strok then
+		return "(" .. table.concat(str) .. ")"
+	else
+		table.insert(u16, ">")
+		return table.concat(u16)
+	end
+end
+
+local function pdf_encode_dict_body(d)
+	local t = {}
+	for k, v in pairs(d) do
+		table.insert(t, "/" .. k .. " " .. v)
+	end
+	return table.concat(t, "\n")
+end
+
+local function pdf_encode_dict(d)
+	return '<< ' .. pdf_encode_dict_body(d) .. ' >>'
+end
+
+-- Metadata dictionary
+
+pdfmeta.info = { }
+pdfmeta.catalog = { }
+
+function pdfmeta.set_info(key, val)
+	pdfmeta.info[key] = pdf_string(val)
+end
+
+local function write_metas()
+	pdfmeta.make_outline()
+	pdf.setinfo(pdf_encode_dict_body(pdfmeta.info))
+	pdf.setcatalog(pdf_encode_dict_body(pdfmeta.catalog))
+end
+
+luatexbase.add_to_callback('finish_pdffile', write_metas, 'Write all PDF metadata')
+
+-- Document outline
+
+pdfmeta.outline = { children = {} }
+pdfmeta.outline_stack = { pdfmeta.outline }
+
+function pdfmeta.add_outline(key, dest, text)
+	local stk = pdfmeta.outline_stack
+	local level = 1
+	local p, r
+
+	for k in string.gmatch(key, '%.*(%d+)') do
+		level = level+1
+	end
+	while #stk >= level do
+		table.remove(stk)
+	end
+	while #stk < level do
+		p = stk[#stk]
+		r = { children = {} }
+		table.insert(p.children, r)
+		table.insert(stk, r)
+	end
+	r.dest = dest
+	text = string.gsub(text, '~', unicode.utf8.char(160))
+	text = string.gsub(text, '%-%-%-', unicode.utf8.char(8212))
+	text = string.gsub(text, '%-%-', unicode.utf8.char(8211))
+	r.text = text;
+end
+
+local function reserve_objects(r)
+	r.obj = pdf.reserveobj()
+	r.num_descendants = 0
+	for i, child in pairs(r.children) do
+		reserve_objects(child)
+		r.num_descendants = r.num_descendants + child.num_descendants + 1
+	end
+end
+
+local function outline_ref(r)
+	if r then
+		return r.obj .. ' 0 R'
+	else
+		tex.error('Asked to format null reference')
+		return 'nil'
+	end
+end
+
+local function gen_outline(r, parent)
+	d = {}
+	r.dict = d
+
+	if not parent then
+		d.Type = '/Outlines'
+		d.Count = r.num_descendants
+	else
+		d.Parent = outline_ref(parent)
+		d.Count = r.num_descendants
+	end
+
+	if r.text then
+		d.Title = pdf_string(r.text)
+		d.A = '<< /D (' .. r.dest .. ') /S /GoTo >>'
+	end
+
+	if r.children[1] then
+		d.First = outline_ref(r.children[1])
+		d.Last = outline_ref(r.children[#r.children])
+		for i, child in pairs(r.children) do
+			gen_outline(child, r)
+			if i>1 then
+				child.dict.Prev = outline_ref(r.children[i-1])
+			end
+			if i<#r.children then
+				child.dict.Next = outline_ref(r.children[i+1])
+			end
+		end
+	end
+end
+
+local function write_outline(r)
+	pdf.obj {
+		type = 'raw',
+		immediate = true,
+		objnum = r.obj,
+		string = pdf_encode_dict(r.dict),
+	}
+	for i, child in pairs(r.children) do
+		write_outline(child)
+	end
+end
+
+function pdfmeta.make_outline()
+	local o = pdfmeta.outline
+	reserve_objects(o)
+	gen_outline(o, nil)
+	-- dump_table(o)
+	write_outline(o)
+	pdfmeta.catalog.Outlines = outline_ref(o)
+end
diff --git a/ucw-pdfmeta.tex b/ucw-pdfmeta.tex
new file mode 100644
index 0000000..0eb832c
--- /dev/null
+++ b/ucw-pdfmeta.tex
@@ -0,0 +1,21 @@
+% The UCW Macro Collection: PDF meta-data (requires LuaTeX)
+% Written by Martin Mares <mj@ucw.cz> in 2018 and placed into public domain
+% -------------------------------------------------------------------------
+
+\ifx\directlua\undefined
+	\def\pdfmetainfo#1#2{}%
+	\def\pdfmetaoutline#1#2#3{}%
+	\endinput
+\fi
+
+\directlua{require('ucw-pdfmeta.lua')}
+
+% Set entry in Info dictionary (usual keys are Author and Title)
+% \pdfmetainfo{key}{value}
+\def\pdfmetainfo#1#2{\directlua{pdfmeta.set_info('\luaescapestring{#1}', '\luaescapestring{#2}')}}
+
+% Add entry to the document outline
+% \pdfmetaoutline{chapter.section.subsec.etc}{link-destination}{text}
+\def\pdfmetaoutline#1#2#3{%
+	\directlua{pdfmeta.add_outline('\luaescapestring{#1}', '\luaescapestring{#2}', '\luaescapestring{#3}')}%
+}