Class: Barby::PngOutputter

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

Overview

Renders the barcode to a PNG image using the “png” gem (gem install png)

Registers the to_png and to_canvas methods

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 ⇒ Object

Returns the value of attribute height.



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# File 'lib/barby/outputter/png_outputter.rb', line 13

def height
  @height
end

#margin ⇒ Object

Returns the value of attribute margin.



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# File 'lib/barby/outputter/png_outputter.rb', line 13

def margin
  @margin
end

#width ⇒ Object

Returns the value of attribute width.



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# File 'lib/barby/outputter/png_outputter.rb', line 13

def width
  @width
end

#xdim ⇒ Object

Returns the value of attribute xdim.



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# File 'lib/barby/outputter/png_outputter.rb', line 13

def xdim
  @xdim
end

#ydim ⇒ Object

Returns the value of attribute ydim.



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# File 'lib/barby/outputter/png_outputter.rb', line 13

def ydim
  @ydim
end

Instance Method Details

#full_height ⇒ Object 



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# File 'lib/barby/outputter/png_outputter.rb', line 74

def full_height
  height + (margin * 2)
end

#full_width ⇒ Object 



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# File 'lib/barby/outputter/png_outputter.rb', line 70

def full_width
  width + (margin * 2)
end

#length ⇒ Object 



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# File 'lib/barby/outputter/png_outputter.rb', line 90

def length
  barcode.two_dimensional? ? encoding.first.length : encoding.length
end

#to_canvas(opts = {}) ⇒ Object

Creates a PNG::Canvas object and renders the barcode on it



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# File 'lib/barby/outputter/png_outputter.rb', line 17

def to_canvas(opts={})
  with_options opts do
    canvas = ChunkyPNG::Canvas.new(full_width, full_height, ChunkyPNG::Color::WHITE)

    if barcode.two_dimensional?
      x, y = margin, margin
      booleans.reverse_each do |line|
        line.each do |bar|
          if bar
            x.upto(x+(xdim-1)) do |xx|
              y.upto y+(ydim-1) do |yy|
                canvas[xx,yy] = ChunkyPNG::Color::Black
              end
            end
          end
          x += xdim
        end
        y += ydim
        x = margin
      end
    else
      x, y = margin, margin
      booleans.each do |bar|
        if bar
          x.upto(x+(xdim-1)) do |xx|
            y.upto y+(height-1) do |yy|
              canvas[xx,yy] = ChunkyPNG::Color::BLACK
            end
          end
        end
        x += xdim
      end
    end

    canvas
  end
end

#to_png(*a) ⇒ Object

Renders the barcode to a PNG image



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# File 'lib/barby/outputter/png_outputter.rb', line 57

def to_png(*a)
  to_canvas(*a).to_blob
end