Class: Libis::Format::Converter::PdfConverter

Inherits:
Base
  • Object
show all
Defined in:
lib/libis/format/converter/pdf_converter.rb

Instance Attribute Summary

Attributes inherited from Base

#flags, #options

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

inherited, #initialize, #using_temp, using_temp

Constructor Details

This class inherits a constructor from Libis::Format::Converter::Base

Class Method Details

.input_types ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 16

def self.input_types
  [:PDF]
end

.output_types(format = nil) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 20

def self.output_types(format = nil)
  return [] unless input_types.include?(format)
  [:PDF, :PDFA]
end

Instance Method Details

#convert(source, target, format, opts = {}) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 101

def convert(source, target, format, opts = {})
  super

  result = nil

  if (quality = @options.delete('optimize'))
    result = optimize_pdf(source, target, quality)
    return nil unless result
    source = result
  end

  unless @options.empty?
    result = convert_pdf(source, target)
    return nil unless result
    source = result
  end

  if format == :PDFA and source
    result = pdf_to_pdfa(source, target)
  end

  result

end

#convert_pdf(source, target) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 138

def convert_pdf(source, target)

  using_temp(target) do |tmpname|
    result = Libis::Format::PdfCopy.run(
        source, tmpname,
        @options.map { |k, v|
          if v.nil?
            nil
          else
            ["--#{k}", (v.is_a?(Array) ? v : v.to_s)]
          end }.flatten
    )
    unless result[:err].empty?
      error("Pdf conversion encountered errors:\n%s", result[:err].join('\n'))
      next nil
    end
    tmpname
  end

end

#metadata(values = {}) ⇒ Object

Set metadata for Pdf file

valid metadata keys are):

- title
- author
- creator
- keywords
- subject

Parameters:

  • values (Hash) (defaults to: {}) —

    list of metadata values to set



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# File 'lib/libis/format/converter/pdf_converter.rb', line 39

def metadata(values = {})
  values.key_strings_to_symbols!
  values.each do |k, v|
    next unless [:title, :author, :creator, :keywords, :subject].include?(k)
    @options["md_#{k}"] = v
  end
end

#optimize(setting = 1) ⇒ Object

Optimize the PDF

This reduces the graphics quality to a level in order to limit file size. This option relies on the presence of ghostscript and takes one argument: the quality level. It should be one of:

  • 0 : lowest quality (Acrobat Distiller ‘Screen Optimized’ equivalent)

  • 1 : medium quality (Acrobat Distiller ‘eBook’ equivalent)

  • 2 : good quality

  • 3 : high quality (Acrobat Distiller ‘Print Optimized’ equivalent)

  • 4 : highest quality (Acrobat Distiller ‘Prepress Optimized’ equivalent)

Note that the optimization is intended to be used with PDF’s containing high-resolution images.

Parameters:

  • setting (Integer) (defaults to: 1) —

    quality setting. [0-4]



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# File 'lib/libis/format/converter/pdf_converter.rb', line 97

def optimize(setting = 1)
  @options['optimize'] = %w(screen ebook default printer prepress)[setting] if (0..4) === setting
end

#optimize_pdf(source, target, quality) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 126

def optimize_pdf(source, target, quality)

  using_temp(target) do |tmpname|
    result = Libis::Format::PdfOptimizer.run(source, tmpname, quality)
    unless result[:status] == 0
      error("Pdf optimization encountered errors:\n%s", (result[:err] + result[:out]).join('\n'))
      next nil
    end
    tmpname
  end
end

#pdf_convert(_) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 25

def pdf_convert(_)
  #force usage of this converter
end

#pdf_to_pdfa(source, target) ⇒ Object 



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# File 'lib/libis/format/converter/pdf_converter.rb', line 159

def pdf_to_pdfa(source, target)

  using_temp(target) do |tmpname|
    result = Libis::Format::PdfToPdfa.run source, tmpname
    unless result[:status] == 0
      error("Pdf/A conversion encountered errors:\n%s", result[:err].join('\n'))
      next nil
    end
    tmpname
  end

end

#range(selection) ⇒ Object

Select a partial list of pages

Parameters:

  • selection (String) —

    as described in com.itextpdf.text.pdf.SequenceList: [!][o][e]start-end



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# File 'lib/libis/format/converter/pdf_converter.rb', line 49

def range(selection)
  @options[:ranges] = selection
end

#watermark(options = {}) ⇒ Object

Create or use a watermark image.

The watermark options are (use symbols):

- text: text to create a watermark from
- file: watermark image to use
- rotation: rotation of the watermark text (in degrees; integer number)
- size: font size of the watermark text
- opacity: opacity of the watermark (fraction 0.0 - 1.0)
- gap: size of the gap between watermark instances. Integer value is absolute size in points (1/72 inch). Fractions are percentage of widht/height.

If both options are given, the file will be used as-is if it exists and is a valid image file. Otherwise the file will be created or overwritten with a newly created watermark image.

The created watermark file will be a PNG image with transparent background containing the supplied text slanted by 30 degrees counter-clockwise.

Parameters:

  • options (Hash) (defaults to: {}) —

    Hash of options for watermark creation.



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# File 'lib/libis/format/converter/pdf_converter.rb', line 69

def watermark(options = {})
  options.key_strings_to_symbols!
  if options[:file] && File.exist?(options[:file])
    @options['wm_image'] = options[:file]
  else
    @options['wm_text'] = (options[:text] || '© LIBIS').split('\n')
    @options['wm_text_rotation'] = options[:rotation] if options[:rotation]
    @options['wm_font_size'] = options[:size] if options[:size]
  end
  @options['wm_opacity'] = options[:opacity] || '0.3'
  @options['wm_gap_ratio'] = options[:gap] if options[:gap].to_s =~ /^\s*(0+\.\d+|1\.0+)\s*$/
  @options['wm_gap_size'] = options[:gap] if options[:gap].to_s =~ /^\s*\d+\s*$/
end