require "../math" --[[ This is a registry for document providers ]]-- DocumentRegistry = { providers = { } } function DocumentRegistry:addProvider(extension, mimetype, provider) table.insert(self.providers, { extension = extension, mimetype = mimetype, provider = provider }) end function DocumentRegistry:getProvider(file) -- TODO: some implementation based on mime types? local extension = string.lower(string.match(file, ".+%.([^.]+)") or "") for _, provider in ipairs(self.providers) do if extension == provider.extension then return provider.provider end end end function DocumentRegistry:openDocument(file) local provider = self:getProvider(file) if provider ~= nil then return provider:new{file = file} end end --[[ This is an abstract interface to a document ]]-- Document = { -- file name file = nil, info = { -- whether the document is pageable has_pages = false, -- whether words can be provided has_words = false, -- whether hyperlinks can be provided has_hyperlinks = false, -- whether (native to format) annotations can be provided has_annotations = false, -- whether pages can be rotated is_rotatable = false, number_of_pages = 0, -- if not pageable, length of the document in pixels doc_height = 0, -- other metadata title = "", author = "", date = "" }, GAMMA_NO_GAMMA = 1.0, -- override bbox from orignal page's getUsedBBox bbox = {}, -- flag to show whether the document was opened successfully is_open = false, error_message = nil, -- flag to show that the document needs to be unlocked by a password is_locked = false, } function Document:new(o) local o = o or {} setmetatable(o, self) self.__index = self if o.init then o:init() end return o end -- override this method to open a document function Document:init() end -- this might be overridden by a document implementation function Document:unlock(password) -- return true instead when the password provided unlocked the document return false end -- this might be overridden by a document implementation function Document:close() if self.is_open then self.is_open = false self._document:close() end end -- this might be overridden by a document implementation function Document:getNativePageDimensions(pageno) local hash = "pgdim|"..self.file.."|"..pageno local cached = Cache:check(hash) if cached then return cached[1] end local page = self._document:openPage(pageno) local page_size_w, page_size_h = page:getSize(self.dc_null) local page_size = Geom:new{ w = page_size_w, h = page_size_h } Cache:insert(hash, CacheItem:new{ page_size }) page:close() return page_size end function Document:_readMetadata() self.info.number_of_pages = self._document:getPages() return true end -- calculates page dimensions function Document:getPageDimensions(pageno, zoom, rotation) local native_dimen = self:getNativePageDimensions(pageno):copy() if rotation == 90 or rotation == 270 then -- switch orientation native_dimen.w, native_dimen.h = native_dimen.h, native_dimen.w end native_dimen:scaleBy(zoom) --DEBUG("dimen for pageno", pageno, "zoom", zoom, "rotation", rotation, "is", native_dimen) return native_dimen end function Document:getPageBBox(pageno) local bbox = self.bbox[pageno] -- exact if bbox ~= nil then --DEBUG("bbox from", pageno) return bbox else local oddEven = math.oddEven(pageno) bbox = self.bbox[oddEven] -- odd/even end if bbox ~= nil then -- last used up to this page --DEBUG("bbox from", oddEven) return bbox else for i = 0,pageno do bbox = self.bbox[ pageno - i ] if bbox ~= nil then --DEBUG("bbox from", pageno - i) return bbox end end end if bbox == nil then -- fallback bbox bbox = self:getUsedBBox(pageno) --DEBUG("bbox from ORIGINAL page") end --DEBUG("final bbox", bbox) return bbox end --[[ This method returns pagesize if bbox is corrupted --]] function Document:getUsedBBoxDimensions(pageno, zoom, rotation) local bbox = self:getPageBBox(pageno) local ubbox_dimen = nil if (bbox.x0 < 0) or (bbox.y0 < 0) or (bbox.x1 < 0) or (bbox.y1 < 0) or (bbox.x0 == bbox.x1) or (bbox.y0 == bbox.y1) then -- if document's bbox info is corrupted, we use the page size ubbox_dimen = self:getPageDimensions(pageno, zoom, rotation) else ubbox_dimen = Geom:new{ x = bbox.x0, y = bbox.y0, w = bbox.x1 - bbox.x0, h = bbox.y1 - bbox.y0, } if zoom ~= 1 then ubbox_dimen:transformByScale(zoom) end end return ubbox_dimen end function Document:getToc() return self._document:getToc() end function Document:getTextBoxes(pageno) return nil end function Document:getOCRWord(pageno, rect) return nil end function Document:renderPage(pageno, rect, zoom, rotation, gamma, render_mode) local hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode local page_size = self:getPageDimensions(pageno, zoom, rotation) -- this will be the size we actually render local size = page_size -- we prefer to render the full page, if it fits into cache if not Cache:willAccept(size.w * size.h / 2) then -- whole page won't fit into cache DEBUG("rendering only part of the page") -- TODO: figure out how to better segment the page if not rect then DEBUG("aborting, since we do not have a specification for that part") -- required part not given, so abort return end -- only render required part hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode.."|"..tostring(rect) size = rect end -- prepare cache item with contained blitbuffer local tile = CacheItem:new{ size = size.w * size.h / 2 + 64, -- estimation excerpt = size, pageno = pageno, bb = Blitbuffer.new(size.w, size.h) } -- create a draw context local dc = DrawContext.new() dc:setRotate(rotation) -- correction of rotation if rotation == 90 then dc:setOffset(page_size.w, 0) elseif rotation == 180 then dc:setOffset(page_size.w, page_size.h) elseif rotation == 270 then dc:setOffset(0, page_size.h) end dc:setZoom(zoom) if gamma ~= self.GAMMA_NO_GAMMA then --DEBUG("gamma correction: ", gamma) dc:setGamma(gamma) end -- render local page = self._document:openPage(pageno) page:draw(dc, tile.bb, size.x, size.y, render_mode) page:close() Cache:insert(hash, tile) return tile end -- a hint for the cache engine to paint a full page to the cache -- TODO: this should trigger a background operation function Document:hintPage(pageno, zoom, rotation, gamma, render_mode) local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode if not Cache:check(hash_full_page) then DEBUG("hinting page", pageno) self:renderPage(pageno, nil, zoom, rotation, gamma, render_mode) end end --[[ Draw page content to blitbuffer. 1. find tile in cache 2. if not found, call renderPage @target: target blitbuffer @rect: visible_area inside document page --]] function Document:drawPage(target, x, y, rect, pageno, zoom, rotation, gamma, render_mode) local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode local hash_excerpt = hash_full_page.."|"..tostring(rect) local tile = Cache:check(hash_full_page) if not tile then tile = Cache:check(hash_excerpt) if not tile then DEBUG("rendering") tile = self:renderPage(pageno, rect, zoom, rotation, gamma, render_mode) end end DEBUG("now painting", tile, rect) target:blitFrom(tile.bb, x, y, rect.x - tile.excerpt.x, rect.y - tile.excerpt.y, rect.w, rect.h) end function Document:getPageText(pageno) -- is this worth caching? not done yet. local page = self._document:openPage(pageno) local text = page:getPageText() page:close() return text end -- load implementations: require "document/pdfdocument" require "document/djvudocument" require "document/credocument"