Class: Barby::CairoOutputter

Inherits:
Outputter show all
Defined in:
lib/barby/outputter/cairo_outputter.rb

Overview

Uses Cairo to render a barcode to a number of formats: PNG, PS, EPS, PDF and SVG

Registers methods render_to_cairo_context, to_png, to_ps, to_eps, to_pdf and to_svg

Instance Attribute Summary collapse

Attributes inherited from Outputter

#barcode

Instance Method Summary collapse

Methods inherited from Outputter

#initialize, register

Constructor Details

This class inherits a constructor from Barby::Outputter

Instance Attribute Details

#height(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 138

def height(options={})
  if barcode.two_dimensional?
    encoding.size * xdim(options)
  else
    @height || options[:height] || 50
  end
end

#margin(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 158

def margin(options={})
  @margin || options[:margin] || 10
end

#x(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 126

def x(options={})
  @x || options[:x]
end

#xdim(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 154

def xdim(options={})
  @xdim || options[:xdim] || 1
end

#y(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 130

def y(options={})
  @y || options[:y]
end

Instance Method Details

#full_height(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 150

def full_height(options={})
  height(options) + (margin(options) * 2)
end

#full_width(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 146

def full_width(options={})
  width(options) + (margin(options) * 2)
end

#render_to_cairo_context(context, options = {}) ⇒ Object

Render the barcode onto a Cairo context



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# File 'lib/barby/outputter/cairo_outputter.rb', line 27

def render_to_cairo_context(context, options={})
  if context.respond_to?(:have_current_point?) and
      context.have_current_point?
    current_x, current_y = context.current_point
  else
    current_x = x(options) || margin(options)
    current_y = y(options) || margin(options)
  end

  _xdim = xdim(options)
  _height = height(options)
  original_current_x = current_x
  context.save do
    context.set_source_color(:black)
    context.fill do
      if barcode.two_dimensional?
        boolean_groups.each do |groups|
          groups.each do |bar,amount|
            current_width = _xdim * amount
            if bar
              context.rectangle(current_x, current_y, current_width, _xdim)
            end
            current_x += current_width
          end
          current_x = original_current_x
          current_y += _xdim
        end
      else
        boolean_groups.each do |bar,amount|
          current_width = _xdim * amount
          if bar
            context.rectangle(current_x, current_y, current_width, _height)
          end
          current_x += current_width
        end
      end
    end
  end

  context
end

#to_eps(options = {}) ⇒ Object

Render the barcode to an EPS document



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# File 'lib/barby/outputter/cairo_outputter.rb', line 97

def to_eps(options={})
  to_ps(options.merge(:eps => true))
end

#to_pdf(options = {}) ⇒ Object

Render the barcode to a PDF document



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# File 'lib/barby/outputter/cairo_outputter.rb', line 103

def to_pdf(options={})
  output_to_string_io do |io|
    Cairo::PDFSurface.new(io,
                          full_width(options),
                          full_height(options)) do |surface|
      render(surface, options)
    end
  end
end

#to_png(options = {}) ⇒ Object

Render the barcode to a PNG image



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# File 'lib/barby/outputter/cairo_outputter.rb', line 71

def to_png(options={})
  output_to_string_io do |io|
    Cairo::ImageSurface.new(options[:format],
                            full_width(options),
                            full_height(options)) do |surface|
      render(surface, options)
      surface.write_to_png(io)
    end
  end
end

#to_ps(options = {}) ⇒ Object

Render the barcode to a PS document



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# File 'lib/barby/outputter/cairo_outputter.rb', line 84

def to_ps(options={})
  output_to_string_io do |io|
    Cairo::PSSurface.new(io,
                         full_width(options),
                         full_height(options)) do |surface|
      surface.eps = options[:eps] if surface.respond_to?(:eps=)
      render(surface, options)
    end
  end
end

#to_svg(options = {}) ⇒ Object

Render the barcode to an SVG document



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# File 'lib/barby/outputter/cairo_outputter.rb', line 115

def to_svg(options={})
  output_to_string_io do |io|
    Cairo::SVGSurface.new(io,
                          full_width(options),
                          full_height(options)) do |surface|
      render(surface, options)
    end
  end
end

#width(options = {}) ⇒ Object 



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# File 'lib/barby/outputter/cairo_outputter.rb', line 134

def width(options={})
  (barcode.two_dimensional? ? encoding.first.length : encoding.length) * xdim(options)
end