diff options
Diffstat (limited to 'tex/context/base/lpdf-epd.lua')
| -rw-r--r-- | tex/context/base/lpdf-epd.lua | 809 |
1 files changed, 634 insertions, 175 deletions
diff --git a/tex/context/base/lpdf-epd.lua b/tex/context/base/lpdf-epd.lua index a7399f6b4..1dc20bc26 100644 --- a/tex/context/base/lpdf-epd.lua +++ b/tex/context/base/lpdf-epd.lua @@ -6,124 +6,287 @@ if not modules then modules = { } end modules ['lpdf-epd'] = { license = "see context related readme files" } --- This is an experimental layer around the epdf library. The reason for --- this layer is that I want to be independent of the library (which --- implements a selection of what a file provides) and also because I --- want an interface closer to Lua's table model while the API stays --- close to the original xpdf library. Of course, after prototyping a --- solution, we can optimize it using the low level epdf accessors. - --- It will be handy when we have a __length and __next that can trigger --- the resolve till then we will provide .n as #. - --- As there can be references to the parent we cannot expand a tree. I --- played with some expansion variants but it does to pay off. - --- Maybe we need a close(). --- We cannot access all destinations in one run. - -local setmetatable, rawset, rawget, tostring, tonumber = setmetatable, rawset, rawget, tostring, tonumber -local lower, match, char, find, sub = string.lower, string.match, string.char, string.find, string.sub +-- This is an experimental layer around the epdf library. The reason for this layer is that +-- I want to be independent of the library (which implements a selection of what a file +-- provides) and also because I want an interface closer to Lua's table model while the API +-- stays close to the original xpdf library. Of course, after prototyping a solution, we can +-- optimize it using the low level epdf accessors. However, not all are accessible (this will +-- be fixed). +-- +-- It will be handy when we have a __length and __next that can trigger the resolve till then +-- we will provide .n as #; maybe in Lua 5.3 or later. +-- +-- As there can be references to the parent we cannot expand a tree. I played with some +-- expansion variants but it does not pay off; adding extra checks is nto worth the trouble. +-- +-- The document stays over. In order to free memory one has to explicitly onload the loaded +-- document. +-- +-- We have much more checking then needed in the prepare functions because occasionally +-- we run into bugs in poppler or the epdf interface. It took us a while to realize that +-- there was a long standing gc issue the on long runs with including many pages could +-- crash the analyzer. +-- +-- Normally a value is fetched by key, as in foo.Title but as it can be in pdfdoc encoding +-- a safer bet is foo("Title") which will return a decoded string (or the original if it +-- already was unicode). + +local setmetatable, rawset, rawget, type = setmetatable, rawset, rawget, type +local tostring, tonumber = tostring, tonumber +local lower, match, char, byte, find = string.lower, string.match, string.char, string.byte, string.find +local abs = math.abs local concat = table.concat -local toutf = string.toutf +local toutf, toeight, utfchar = string.toutf, utf.toeight, utf.char + +local lpegmatch, lpegpatterns = lpeg.match, lpeg.patterns +local P, C, S, R, Ct, Cc, V, Carg, Cs, Cf, Cg = lpeg.P, lpeg.C, lpeg.S, lpeg.R, lpeg.Ct, lpeg.Cc, lpeg.V, lpeg.Carg, lpeg.Cs, lpeg.Cf, lpeg.Cg + +local epdf = epdf + lpdf = lpdf or { } +local lpdf = lpdf +local lpdf_epdf = { } +lpdf.epdf = lpdf_epdf + +local pdf_open = epdf.open + +local report_epdf = logs.reporter("epdf") + +local getDict, getArray, getReal, getNum, getString, getBool, getName, getRef, getRefNum +local getType, getTypeName +local dictGetLength, dictGetVal, dictGetValNF, dictGetKey +local arrayGetLength, arrayGetNF, arrayGet +local streamReset, streamGetDict, streamGetChar + +do + local object = epdf.Object() + -- + getDict = object.getDict + getArray = object.getArray + getReal = object.getReal + getNum = object.getNum + getString = object.getString + getBool = object.getBool + getName = object.getName + getRef = object.getRef + getRefNum = object.getRefNum + -- + getType = object.getType + getTypeName = object.getTypeName + -- + streamReset = object.streamReset + streamGetDict = object.streamGetDict + streamGetChar = object.streamGetChar + -- +end -local report_epdf = logs.reporter("epdf") +local function initialize_methods(xref) + local dictionary = epdf.Dict(xref) + local array = epdf.Array(xref) + -- + dictGetLength = dictionary.getLength + dictGetVal = dictionary.getVal + dictGetValNF = dictionary.getValNF + dictGetKey = dictionary.getKey + -- + arrayGetLength = array.getLength + arrayGetNF = array.getNF + arrayGet = array.get + -- + initialize_methods = function() + -- already done + end +end --- a bit of protection +local typenames = { [0] = + "boolean", + "integer", + "real", + "string", + "name", + "null", + "array", + "dictionary", + "stream", + "ref", + "cmd", + "error", + "eof", + "none", + "integer64", +} -local limited = false +local typenumbers = table.swapped(typenames) -directives.register("system.inputmode", function(v) - if not limited then - local i_limiter = io.i_limiter(v) - if i_limiter then - epdf.open = i_limiter.protect(epdf.open) - limited = true - end - end -end) +local null_code = typenumbers.null +local ref_code = typenumbers.ref --- +local function fatal_error(...) + report_epdf(...) + report_epdf("aborting job in order to avoid crash") + os.exit() +end + +-- epdf is the built-in library function epdf.type(o) local t = lower(match(tostring(o),"[^ :]+")) return t or "?" end -lpdf = lpdf or { } -local lpdf = lpdf +local checked_access + +-- dictionaries (can be optimized: ... resolve and redefine when all locals set) -lpdf.epdf = { } +local frompdfdoc = lpdf.frompdfdoc -local checked_access +local function get_flagged(t,f,k) + local fk = f[k] + if not fk then + return t[k] + elseif fk == "rawtext" then + return frompdfdoc(t[k]) + else -- no other flags yet + return t[k] + end +end -local function prepare(document,d,t,n,k,mt) +local function prepare(document,d,t,n,k,mt,flags) for i=1,n do - local v = d:getVal(i) - local r = d:getValNF(i) - if r:getTypeName() == "ref" then - r = r:getRef().num - local c = document.cache[r] - if c then - -- + local v = dictGetVal(d,i) + if v then + local r = dictGetValNF(d,i) + local kind = getType(v) + if kind == null_code then + -- ignore else - c = checked_access[v:getTypeName()](v,document,r) - if c then - document.cache[r] = c - document.xrefs[c] = r + local key = dictGetKey(d,i) + if kind then + if r and getType(r) == ref_code then + local objnum = getRefNum(r) + local cached = document.__cache__[objnum] + if not cached then + cached = checked_access[kind](v,document,objnum,mt) + if c then + document.__cache__[objnum] = cached + document.__xrefs__[cached] = objnum + end + end + t[key] = cached + else + local v, flag = checked_access[kind](v,document) + t[key] = v + if flag and flags then + flags[key] = flag -- flags + end + end + else + report_epdf("warning: nil value for key %a in dictionary",key) end end - t[d:getKey(i)] = c else - t[d:getKey(i)] = checked_access[v:getTypeName()](v,document) + fatal_error("error: invalid value at index %a in dictionary of %a",i,document.filename) end end - getmetatable(t).__index = nil -- ?? weird -setmetatable(t,mt) + if mt then + setmetatable(t,mt) + else + getmetatable(t).__index = nil + end return t[k] end -local function some_dictionary(d,document,r,mt) - local n = d and d:getLength() or 0 +local function some_dictionary(d,document) + local n = d and dictGetLength(d) or 0 + if n > 0 then + local t = { } + local f = { } + setmetatable(t, { + __index = function(t,k) + return prepare(document,d,t,n,k,_,_,f) + end, + __call = function(t,k) + return get_flagged(t,f,k) + end, + } ) + return t + end +end + +local function get_dictionary(object,document,r,mt) + local d = getDict(object) + local n = d and dictGetLength(d) or 0 if n > 0 then local t = { } - setmetatable(t, { __index = function(t,k) return prepare(document,d,t,n,k,mt) end } ) + local f = { } + setmetatable(t, { + __index = function(t,k) + return prepare(document,d,t,n,k,mt,f) + end, + __call = function(t,k) + return get_flagged(t,f,k) + end, + } ) return t end end -local done = { } +-- arrays (can be optimized: ... resolve and redefine when all locals set) local function prepare(document,a,t,n,k) for i=1,n do - local v = a:get(i) - local r = a:getNF(i) - if v:getTypeName() == "null" then - -- TH: weird, but appears possible - elseif r:getTypeName() == "ref" then - r = r:getRef().num - local c = document.cache[r] - if c then - -- + local v = arrayGet(a,i) + if v then + local kind = getType(v) + if kind == null_code then + -- ignore + elseif kind then + local r = arrayGetNF(a,i) + if r and getType(r) == ref_code then + local objnum = getRefNum(r) + local cached = document.__cache__[objnum] + if not cached then + cached = checked_access[kind](v,document,objnum) + document.__cache__[objnum] = cached + document.__xrefs__[cached] = objnum + end + t[i] = cached + else + t[i] = checked_access[kind](v,document) + end else - c = checked_access[v:getTypeName()](v,document,r) - document.cache[r] = c - document.xrefs[c] = r + report_epdf("warning: nil value for index %a in array",i) end - t[i] = c else - t[i] = checked_access[v:getTypeName()](v,document) + fatal_error("error: invalid value at index %a in array of %a",i,document.filename) end end getmetatable(t).__index = nil return t[k] end -local function some_array(a,document,r) - local n = a and a:getLength() or 0 +local function some_array(a,document) + local n = a and arrayGetLength(a) or 0 if n > 0 then local t = { n = n } - setmetatable(t, { __index = function(t,k) return prepare(document,a,t,n,k) end } ) + setmetatable(t, { + __index = function(t,k) + return prepare(document,a,t,n,k) + end + } ) + return t + end +end + +local function get_array(object,document) + local a = getArray(object) + local n = a and arrayGetLength(a) or 0 + if n > 0 then + local t = { n = n } + setmetatable(t, { + __index = function(t,k) + return prepare(document,a,t,n,k) + end + } ) return t end end @@ -131,9 +294,9 @@ end local function streamaccess(s,_,what) if not what or what == "all" or what == "*all" then local t, n = { }, 0 - s:streamReset() + streamReset(s) while true do - local c = s:streamGetChar() + local c = streamGetChar(s) if c < 0 then break else @@ -145,56 +308,96 @@ local function streamaccess(s,_,what) end end -local function some_stream(d,document,r) +local function get_stream(d,document) if d then - d:streamReset() - local s = some_dictionary(d:streamGetDict(),document,r) + streamReset(d) + local s = some_dictionary(streamGetDict(d),document) getmetatable(s).__call = function(...) return streamaccess(d,...) end return s end end --- we need epdf.boolean(v) in addition to v:getBool() [dictionary, array, stream, real, integer, string, boolean, name, ref, null] - -checked_access = { - dictionary = function(d,document,r) - return some_dictionary(d:getDict(),document,r) - end, - array = function(a,document,r) - return some_array(a:getArray(),document,r) - end, - stream = function(v,document,r) - return some_stream(v,document,r) - end, - real = function(v) - return v:getReal() - end, - integer = function(v) - return v:getNum() - end, - string = function(v) - return toutf(v:getString()) - end, - boolean = function(v) - return v:getBool() - end, - name = function(v) - return v:getName() - end, - ref = function(v) - return v:getRef() - end, - null = function() - return nil - end, -} +-- We need to convert the string from utf16 although there is no way to +-- check if we have a regular string starting with a bom. So, we have +-- na dilemma here: a pdf doc encoded string can be invalid utf. --- checked_access.real = epdf.real --- checked_access.integer = epdf.integer --- checked_access.string = epdf.string --- checked_access.boolean = epdf.boolean --- checked_access.name = epdf.name --- checked_access.ref = epdf.ref +-- <hex encoded> : implicit 0 appended if odd +-- (byte encoded) : \( \) \\ escaped +-- +-- <FE><FF> : utf16be +-- +-- \r \r \t \b \f \( \) \\ \NNN and \<newline> : append next line +-- +-- the getString function gives back bytes so we don't need to worry about +-- the hex aspect. + +local u_pattern = lpeg.patterns.utfbom_16_be * lpeg.patterns.utf16_to_utf8_be +----- b_pattern = lpeg.patterns.hextobytes + +local function get_string(v) + -- the toutf function only converts a utf16 string and leves the original + -- untouched otherwise; one might want to apply lpdf.frompdfdoc to a + -- non-unicode string + local s = getString(v) + if not s or s == "" then + return "" + end + local u = lpegmatch(u_pattern,s) + if u then + return u -- , "unicode" + end + -- this is too tricky and fails on e.g. reload of url www.pragma-ade.com) + -- local b = lpegmatch(b_pattern,s) + -- if b then + -- return b, "rawtext" + -- end + return s, "rawtext" +end + +local function get_null() + return nil +end + +-- we have dual access: by typenumber and by typename + +local function invalidaccess(k,document) + local fullname = type(document) == "table" and document.fullname + if fullname then + fatal_error("error, asking for key %a in checker of %a",k,fullname) + else + fatal_error("error, asking for key %a in checker",k) + end +end + +checked_access = table.setmetatableindex(function(t,k) + return function(v,document) + invalidaccess(k,document) + end +end) + +checked_access[typenumbers.boolean] = getBool +checked_access[typenumbers.integer] = getNum +checked_access[typenumbers.real] = getReal +checked_access[typenumbers.string] = get_string -- getString +checked_access[typenumbers.name] = getName +checked_access[typenumbers.null] = get_null +checked_access[typenumbers.array] = get_array -- d,document,r +checked_access[typenumbers.dictionary] = get_dictionary -- d,document,r +checked_access[typenumbers.stream] = get_stream +checked_access[typenumbers.ref] = getRef + +for i=0,#typenames do + local checker = checked_access[i] + if not checker then + checker = function() + return function(v,document) + invalidaccess(i,document) + end + end + checked_access[i] = checker + end + checked_access[typenames[i]] = checker +end local function getnames(document,n,target) -- direct if n then @@ -252,7 +455,6 @@ local function getlayers(document) local n = layers.n for i=1,n do local layer = layers[i] ---~ print(document.xrefs[layer]) t[i] = layer.Name end t.n = n @@ -261,52 +463,39 @@ local function getlayers(document) end end +local function getstructure(document) + -- this might become a tree + return document.Catalog.StructTreeRoot +end local function getpages(document,Catalog) - local data = document.data - local xrefs = document.xrefs - local cache = document.cache - local cata = data:getCatalog() - local xref = data:getXRef() - local pages = { } - local nofpages = cata:getNumPages() --- local function getpagestuff(pagenumber,k) --- if k == "MediaBox" then --- local pageobj = cata:getPage(pagenumber) --- local pagebox = pageobj:getMediaBox() --- return { pagebox.x1, pagebox.y1, pagebox.x2, pagebox.y2 } --- elseif k == "CropBox" then --- local pageobj = cata:getPage(pagenumber) --- local pagebox = pageobj:getMediaBox() --- return { pagebox.x1, pagebox.y1, pagebox.x2, pagebox.y2 } --- elseif k == "Resources" then --- print("todo page resources from parent") --- -- local pageobj = cata:getPage(pagenumber) --- -- local resources = pageobj:getResources() --- end --- end --- for pagenumber=1,nofpages do --- local mt = { __index = function(t,k) --- local v = getpagestuff(pagenumber,k) --- if v then --- t[k] = v --- end --- return v --- end } - local mt = { __index = Catalog.Pages } + local __data__ = document.__data__ + local __xrefs__ = document.__xrefs__ + local __cache__ = document.__cache__ + local __xref__ = document.__xref__ + -- + local catalog = __data__:getCatalog() + local pages = { } + local nofpages = catalog:getNumPages() + local metatable = { __index = Catalog.Pages } + -- for pagenumber=1,nofpages do - local pagereference = cata:getPageRef(pagenumber).num - local pagedata = some_dictionary(xref:fetch(pagereference,0):getDict(),document,pagereference,mt) + local pagereference = catalog:getPageRef(pagenumber).num + local pageobject = __xref__:fetch(pagereference,0) + local pagedata = get_dictionary(pageobject,document,pagereference,metatable) if pagedata then - pagedata.number = pagenumber - pages[pagenumber] = pagedata - xrefs[pagedata] = pagereference - cache[pagereference] = pagedata + -- rawset(pagedata,"number",pagenumber) + pagedata.number = pagenumber + pages[pagenumber] = pagedata + __xrefs__[pagedata] = pagereference + __cache__[pagereference] = pagedata else report_epdf("missing pagedata at slot %i",i) end end + -- pages.n = nofpages + -- return pages end @@ -329,23 +518,29 @@ end local loaded = { } -function lpdf.epdf.load(filename) +function lpdf_epdf.load(filename) local document = loaded[filename] if not document then - statistics.starttiming(lpdf.epdf) - local data = epdf.open(filename) -- maybe resolvers.find_file - if data then + statistics.starttiming(lpdf_epdf) + local __data__ = pdf_open(filename) -- maybe resolvers.find_file + if __data__ then + local __xref__ = __data__:getXRef() document = { - filename = filename, - cache = { }, - xrefs = { }, - data = data, + filename = filename, + __cache__ = { }, + __xrefs__ = { }, + __fonts__ = { }, + __data__ = __data__, + __xref__ = __xref__, } - local Catalog = some_dictionary(data:getXRef():getCatalog():getDict(),document) - local Info = some_dictionary(data:getXRef():getDocInfo():getDict(),document) - document.Catalog = Catalog - document.Info = Info - -- document.catalog = Catalog + -- + initialize_methods(__xref__) + -- + local Catalog = some_dictionary(__xref__:getCatalog():getDict(),document) + local Info = some_dictionary(__xref__:getDocInfo():getDict(),document) + -- + document.Catalog = Catalog + document.Info = Info -- a few handy helper tables document.pages = delayed(document,"pages", function() return getpages(document,Catalog) end) document.destinations = delayed(document,"destinations", function() return getnames(document,Catalog.Names and Catalog.Names.Dests) end) @@ -353,28 +548,292 @@ function lpdf.epdf.load(filename) document.widgets = delayed(document,"widgets", function() return getnames(document,Catalog.Names and Catalog.Names.AcroForm) end) document.embeddedfiles = delayed(document,"embeddedfiles",function() return getnames(document,Catalog.Names and Catalog.Names.EmbeddedFiles) end) document.layers = delayed(document,"layers", function() return getlayers(document) end) + document.structure = delayed(document,"structure", function() return getstructure(document) end) else document = false end loaded[filename] = document - statistics.stoptiming(lpdf.epdf) - -- print(statistics.elapsedtime(lpdf.epdf)) + loaded[document] = document + statistics.stoptiming(lpdf_epdf) + -- print(statistics.elapsedtime(lpdf_epdf)) + end + return document or nil +end + +function lpdf_epdf.unload(filename) + local document = loaded[filename] + if document then + loaded[document] = nil + loaded[filename] = nil end - return document end -- for k, v in next, expand(t) do -function lpdf.epdf.expand(t) +local function expand(t) if type(t) == "table" then local dummy = t.dummy end return t end +-- for k, v in expanded(t) do + +local function expanded(t) + if type(t) == "table" then + local dummy = t.dummy + end + return next, t +end + +lpdf_epdf.expand = expand +lpdf_epdf.expanded = expanded + +-- we could resolve the text stream in one pass if we directly handle the +-- font but why should we complicate things + +local hexdigit = R("09","AF") +local numchar = ( P("\\") * ( (R("09")^3/tonumber) + C(1) ) ) + C(1) +local number = lpegpatterns.number / tonumber +local spaces = lpegpatterns.whitespace^1 +local optspaces = lpegpatterns.whitespace^0 +local keyword = P("/") * C(R("AZ","az","09")^1) +local operator = C((R("AZ","az")+P("'")+P('"'))^1) + +local grammar = P { "start", + start = (keyword + number + V("dictionary") + V("unicode") + V("string") + V("unicode")+ V("array") + spaces)^1, + -- keyvalue = (keyword * spaces * V("start") + spaces)^1, + keyvalue = optspaces * Cf(Ct("") * Cg(keyword * optspaces * V("start") * optspaces)^1,rawset), + array = P("[") * Ct(V("start")^1) * P("]"), + dictionary = P("<<") * V("keyvalue") * P(">>"), + unicode = P("<") * Ct(Cc("hex") * C((1-P(">"))^1)) * P(">"), + string = P("(") * Ct(Cc("dec") * C((V("string")+numchar)^1)) * P(")"), -- untested +} + +local operation = Ct(grammar^1 * operator) +local parser = Ct((operation + P(1))^1) + +-- beginbfrange : <start> <stop> <firstcode> +-- <start> <stop> [ <firstsequence> <firstsequence> <firstsequence> ] +-- beginbfchar : <code> <newcodes> + +local fromsixteen = lpdf.fromsixteen -- maybe inline the lpeg ... but not worth it + +local function f_bfchar(t,a,b) + t[tonumber(a,16)] = fromsixteen(b) +end + +local function f_bfrange_1(t,a,b,c) + print("todo 1",a,b,c) + -- c is string + -- todo t[tonumber(a,16)] = fromsixteen(b) +end + +local function f_bfrange_2(t,a,b,c) + print("todo 2",a,b,c) + -- c is table + -- todo t[tonumber(a,16)] = fromsixteen(b) +end + +local optionals = spaces^0 +local hexstring = optionals * P("<") * C((1-P(">"))^1) * P(">") +local bfchar = Carg(1) * hexstring * hexstring / f_bfchar +local bfrange = Carg(1) * hexstring * hexstring * hexstring / f_bfrange_1 + + Carg(1) * hexstring * hexstring * optionals * P("[") * Ct(hexstring^1) * optionals * P("]") / f_bfrange_2 +local fromunicode = ( + P("beginbfchar" ) * bfchar ^1 * optionals * P("endbfchar" ) + + P("beginbfrange") * bfrange^1 * optionals * P("endbfrange") + + spaces + + P(1) +)^1 * Carg(1) + +local function analyzefonts(document,resources) -- unfinished + local fonts = document.__fonts__ + if resources then + local fontlist = resources.Font + if fontlist then + for id, data in expanded(fontlist) do + if not fonts[id] then + -- a quck hack ... I will look into it more detail if I find a real + -- -application for it + local tounicode = data.ToUnicode() + if tounicode then + tounicode = lpegmatch(fromunicode,tounicode,1,{}) + end + fonts[id] = { + tounicode = type(tounicode) == "table" and tounicode or { } + } + table.setmetatableindex(fonts[id],"self") + end + end + end + end + return fonts +end + +local more = 0 +local unic = nil -- cheaper than passing each time as Carg(1) + +local p_hex_to_utf = C(4) / function(s) -- needs checking ! + local now = tonumber(s,16) + if more > 0 then + now = (more-0xD800)*0x400 + (now-0xDC00) + 0x10000 -- the 0x10000 smells wrong + more = 0 + return unic[now] or utfchar(now) + elseif now >= 0xD800 and now <= 0xDBFF then + more = now + -- return "" + else + return unic[now] or utfchar(now) + end +end + +local p_dec_to_utf = C(1) / function(s) -- needs checking ! + local now = byte(s) + return unic[now] or utfchar(now) +end + +local p_hex_to_utf = P(true) / function() more = 0 end * Cs(p_hex_to_utf^1) +local p_dec_to_utf = P(true) / function() more = 0 end * Cs(p_dec_to_utf^1) + +function lpdf_epdf.getpagecontent(document,pagenumber) + + local page = document.pages[pagenumber] + + if not page then + return + end + + local fonts = analyzefonts(document,page.Resources) + + local content = page.Contents() or "" + local list = lpegmatch(parser,content) + local font = nil + -- local unic = nil + + for i=1,#list do + local entry = list[i] + local size = #entry + local operator = entry[size] + if operator == "Tf" then + font = fonts[entry[1]] + unic = font.tounicode + elseif operator == "TJ" then -- { array, TJ } + local list = entry[1] + for i=1,#list do + local li = list[i] + if type(li) == "table" then + if li[1] == "hex" then + list[i] = lpegmatch(p_hex_to_utf,li[2]) + else + list[i] = lpegmatch(p_dec_to_utf,li[2]) + end + else + -- kern + end + end + elseif operator == "Tj" or operator == "'" or operator == '"' then -- { string, Tj } { string, ' } { n, m, string, " } + local list = entry[size-1] + if list[1] == "hex" then + list[2] = lpegmatch(p_hex_to_utf,li[2]) + else + list[2] = lpegmatch(p_dec_to_utf,li[2]) + end + end + end + + unic = nil -- can be collected + + return list + +end + +-- This is also an experiment. When I really neet it I can improve it, fo rinstance +-- with proper position calculating. It might be usefull for some search or so. + +local softhyphen = utfchar(0xAD) .. "$" +local linefactor = 1.3 + +function lpdf_epdf.contenttotext(document,list) -- maybe signal fonts + local last_y = 0 + local last_f = 0 + local text = { } + local last = 0 + + for i=1,#list do + local entry = list[i] + local size = #entry + local operator = entry[size] + if operator == "Tf" then + last_f = entry[2] + elseif operator == "TJ" then + local list = entry[1] + for i=1,#list do + local li = list[i] + if type(li) == "string" then + last = last + 1 + text[last] = li + elseif li < -50 then + last = last + 1 + text[last] = " " + end + end + line = concat(list) + elseif operator == "Tj" then + last = last + 1 + text[last] = entry[size-1] + elseif operator == "cm" or operator == "Tm" then + local ty = entry[6] + local dy = abs(last_y - ty) + if dy > linefactor*last_f then + if last > 0 then + if find(text[last],softhyphen) then + -- ignore + else + last = last + 1 + text[last] = "\n" + end + end + end + last_y = ty + end + end + + return concat(text) +end + +function lpdf_epdf.getstructure(document,list) -- just a test + local depth = 0 + for i=1,#list do + local entry = list[i] + local size = #entry + local operator = entry[size] + if operator == "BDC" then + report_epdf("%w%s : %s",depth,entry[1] or "?",entry[2].MCID or "?") + depth = depth + 1 + elseif operator == "EMC" then + depth = depth - 1 + elseif operator == "TJ" then + local list = entry[1] + for i=1,#list do + local li = list[i] + if type(li) == "string" then + report_epdf("%w > %s",depth,li) + elseif li < -50 then + report_epdf("%w >",depth,li) + end + end + elseif operator == "Tj" then + report_epdf("%w > %s",depth,entry[size-1]) + end + end +end + +-- document.Catalog.StructTreeRoot.ParentTree.Nums[2][1].A.P[1]) + -- helpers --- function lpdf.epdf.getdestinationpage(document,name) --- local destination = document.data:findDest(name) +-- function lpdf_epdf.getdestinationpage(document,name) +-- local destination = document.__data__:findDest(name) -- return destination and destination.number -- end |