koreader/djvureader.lua

require "unireader"

DJVUReader = UniReader:new{}

-- open a DJVU file and its settings store
-- DJVU does not support password yet
function DJVUReader:open(filename)
	local ok
	ok, self.doc = pcall(djvu.openDocument, filename, self.cache_document_size)
	if not ok then
		return ok, self.doc -- this will be the error message instead
	end
	return ok
end

function DJVUReader:init()
	self:addAllCommands()
	self:adjustDjvuReaderCommand()
end

function DJVUReader:adjustDjvuReaderCommand()
	self.commands:del(KEY_J, MOD_SHIFT, "J")
	self.commands:del(KEY_K, MOD_SHIFT, "K")
	self.commands:add(KEY_R, nil, "R",
		"select djvu page rendering mode",
		function(self)
			self:select_render_mode()
	end) 
end

-- select the rendering mode from those supported by djvulibre.
-- Note that if the values in the definition of ddjvu_render_mode_t in djvulibre/libdjvu/ddjvuapi.h change,
-- then we should update our values here also. This is a bit risky, but these values never change, so it should be ok :)
function DJVUReader:select_render_mode()
	local mode_menu = SelectMenu:new{
		menu_title = "Select DjVu page rendering mode",
		item_array = {
			"COLOUR (works for both colour and b&w pages)",		--  0  (colour page or stencil)
			"BLACK & WHITE (for b&w pages only, much faster)",	--  1  (stencil or colour page)
			"COLOUR ONLY (slightly faster than COLOUR)",		--  2  (colour page or fail)
			"MASK ONLY (for b&w pages only)",					--  3  (stencil or fail)
			"COLOUR BACKGROUND (show only background)",			--  4  (colour background layer)
			"COLOUR FOREGROUND (show only foreground)"			--  5  (colour foreground layer)
			},
		current_entry = self.render_mode,
	}
	local mode = mode_menu:choose(0, fb.bb:getHeight()) 
	if mode then
		self.render_mode = mode - 1
		self:clearCache()
	end
	self:redrawCurrentPage()
end

----------------------------------------------------
-- highlight support 
----------------------------------------------------
function DJVUReader:getText(pageno)
	return self.doc:getPageText(pageno)
end

-- for incompatible API fixing
function DJVUReader:invertTextYAxel(pageno, text_table)
	local _, height = self.doc:getOriginalPageSize(pageno)
	for _,text in pairs(text_table) do
		for _,line in ipairs(text) do
			line.y0, line.y1 = (height - line.y1), (height - line.y0)
		end
	end
	return text_table
end