Module: CombinePDF::PDFFilter

Defined in:
lib/combine_pdf/combine_pdf_filter.rb

Overview

:nodoc: all

Class Method Summary collapse

Class Method Details

.deflate_object(object = nil) ⇒ Object 



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# File 'lib/combine_pdf/combine_pdf_filter.rb', line 13

def deflate_object object = nil
	false
end

.inflate_object(object = nil, filter = :none) ⇒ Object 



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# File 'lib/combine_pdf/combine_pdf_filter.rb', line 17

def inflate_object object = nil, filter = :none
	filter_array = object[:Filter]
	if filter_array.is_a?(Hash) && filter_array[:is_reference_only]
		filter_array = filter_array[:referenced_object]
	end
	if filter_array.is_a?(Symbol)
		filter_array = [filter_array]
	end
	filter_array = [] if filter_array.nil?
	params_array = object[:DecodeParms]
	if params_array.is_a?(Hash) && params_array[:is_reference_only]
		params_array = params_array[:referenced_object]
	end
	unless params_array.is_a?(Array)
		params_array = [params_array]
	end
	while filter_array[0]
		case filter_array[0]
		when :FlateDecode
			raise_unsupported_error params_array[0] unless params_array[0].nil?
			if params_array[0] && params_array[0][:Predictor].to_i > 1
				bits = params_array[0][:BitsPerComponent] || 8
				predictor = params_array[0][:Predictor].to_i
				columns = params_array[0][:Columns] || 1
				if (2..9).include? params_array[0][:Predictor].to_i
					####
					# prepare TIFF group
				elsif (10..15).include? params_array[0][:Predictor].to_i == 2
					####
					# prepare PNG group
				end
			else
				object[:raw_stream_content] = Zlib::Inflate.inflate object[:raw_stream_content]
				object[:Length] = object[:raw_stream_content].bytesize
			end
		when nil
			true
		else
			return false
		end
		params_array.shift
		filter_array.shift
	end
	object.delete(:Filter)
	true
end

.raise_unsupported_error(object = {}) ⇒ Object 



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# File 'lib/combine_pdf/combine_pdf_filter.rb', line 63

def raise_unsupported_error (object = {})
	raise "Filter #{object} unsupported. couldn't deflate object"
end