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Diffstat (limited to 'tex/context/base/lpdf-epd.lua')
| -rw-r--r-- | tex/context/base/lpdf-epd.lua | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/tex/context/base/lpdf-epd.lua b/tex/context/base/lpdf-epd.lua new file mode 100644 index 000000000..23ab0674c --- /dev/null +++ b/tex/context/base/lpdf-epd.lua @@ -0,0 +1,246 @@ +if not modules then modules = { } end modules ['lpdf-epd'] = { + version = 1.001, + comment = "companion to lpdf-epa.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +-- This is an experimental layer around the epdf library. Because that +-- library is not yet finished and will get a clear api (independent of +-- the underlying pdf library which has an instable api) it will take +-- a while before this module is completed. Also, some integration with +-- other lpdf code might happen (i.e. we might generate lpdf objects). + +local setmetatable, rawset = setmetatable, rawset + +-- used: +-- +-- arrayGet arrayGetNF dictLookup getTypeName arrayGetLength +-- getNum getString getBool getName getRef +-- getResourceDict getMediaBox getCropBox getBleedBox getTrimBox getArtBox +-- getPageRef getKindName findDestgetNumPages getDests getPage getCatalog getAnnots + +-- -- -- helpers -- -- -- + +local cache_lookups = false + +local checked_access + +local array_access = { + __index = function(t,k) + local d = t.__data__ + if tonumber(k) then + return checked_access(t,k,d:arrayGetNF(k)) + elseif k == "all" then + local result = { } + for i=1,t.size do + result[i] = checked_access(t,k,d:arrayGetNF(i)) + end + return result + elseif k == "width" then + return checked_access(t,k,d:arrayGetNF(3)) - checked_access(t,k,d:arrayGetNF(1)) + elseif k == "height" then + return checked_access(t,k,d:arrayGetNF(4)) - checked_access(t,k,d:arrayGetNF(2)) + end + end, +} + +local dictionary_access = { + __index = function(t,k) + return checked_access(t,k,t.__data__:dictLookup(k)) + end +} + +checked_access = function(tab,key,v) + local n = v:getTypeName() +--~ print("!!!!!!!!!!!!!!",n) + if n == "array" then + local t = { __data__ = v, size = v:arrayGetLength() } + setmetatable(t,array_access) + if cache_lookups then rawset(tab,key,t) end + return t + elseif n == "dictionary" then + local t = { __data__ = v, } + setmetatable(t,dictionary_access) + if cache_lookups then rawset(tab,key,t) end + return t + elseif n == "real" or n == "integer" then + return v:getNum() + elseif n == "string" then + return v:getString() + elseif n == "boolean" then + return v:getBool() + elseif n == "name" then + return v:getName() + elseif n == "ref" then + return v:getRef(v.num,v.gen) + else + return v + end +end + +local basic_annots_access = { + __index = function(t,k) + local a = { + __data__ = t.__data__:arrayGet(k), + } + setmetatable(a,dictionary_access) + if cache_lookups then rawset(t,k,a) end + return a + end +} + +local basic_resources_access = { -- == dictionary_access + __index = function(t,k) +--~ local d = t.__data__ +--~ print(d) +--~ print(d:getTypeName()) + return checked_access(t,k,t.__data__:dictLookup(k)) + end +} + +local basic_box_access = { + __index = function(t,k) + local d = t.__data__ + if k == "all" then return { d.x1, d.y1, d.x2, d.y2 } + elseif k == "width" then return d.x2 - d.x1 + elseif k == "height" then return d.y2 - d.y1 + elseif k == 1 then return d.x1 + elseif k == 2 then return d.y1 + elseif k == 3 then return d.x2 + elseif k == 4 then return d.y2 + else return 0 end + end +} + +-- -- -- pages -- -- -- + +local page_access = { + __index = function(t,k) + local d = t.__data__ + if k == "Annots" then + local annots = d:getAnnots() + local a = { + __data__ = annots, + size = annots:arrayGetLength() + } + setmetatable(a,basic_annots_access) + rawset(t,k,a) + return a + elseif k == "Resources" then + local r = { + __data__ = d:getResourceDict(), + } + setmetatable(r,basic_resources_access) + rawset(t,k,r) + return r + elseif k == "MediaBox" or k == "TrimBox" or k == "CropBox" or k == "ArtBox" or k == "BleedBox" then + local b = { + -- __data__ = d:getMediaBox(), + __data__ = d["get"..k](d), + } + setmetatable(b,basic_box_access) + rawset(t,k,b) + return b + end + end +} + +-- -- -- catalog -- -- -- + +local destination_access = { + __index = function(t,k) + if k == "D" then + local d = t.__data__ + local p = { + d:getPageRef(k), d:getKindName(k) + } + if cache_lookups then rawset(t,k,p) end -- not needed + return p + end + end +} + +local destinations_access = { + __index = function(t,k) + local d = t.__catalog__ + local p = { + __data__ = d:findDest(k), + } + setmetatable(p,destination_access) + if cache_lookups then rawset(t,k,p) end + return p + end +} + +local catalog_access = { + __index = function(t,k) + local c = t.__catalog__ + if k == "Pages" then + local s = c:getNumPages() + local r = { + } + local p = { + __catalog__ = c, + size = s, + references = r, + } + -- we load all pages as we need to resolve refs + for i=1,s do + local di, ri = c:getPage(i), c:getPageRef(i) + local pi = { + __data__ = di, + reference = ri, + number = i, + } + setmetatable(pi,page_access) + p[i], r[ri.num] = pi, i + end + -- setmetatable(p,pages_access) + rawset(t,k,p) + return p + elseif k == "Destinations" or k == "Dest" then + local d = c:getDests() + local p = { + __catalog__ = c, + } + setmetatable(p,destinations_access) + rawset(t,k,p) + return p + elseif k == "Metadata" then + local m = c:readMetadata() + local p = { -- we fake a stream dictionary + __catalog__ = c, + stream = m, + Type = "Metadata", + Subtype = "XML", + Length = #m, + } + -- rawset(t,k,p) + return p + end + end +} + +local document_access = { + __index = function(t,k) + if k == "Catalog" then + local c = { + __catalog__ = t.__root__:getCatalog(), + } + setmetatable(c,catalog_access) + rawset(t,k,c) + return c + end + end +} + +function lpdf.load(filename) + local document = { + __root__ = epdf.open(filename), + filename = filename, + } + setmetatable(document,document_access) + return document +end |