Class: Barby::RmagickOutputter

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

Overview

Renders images from barcodes using RMagick

Registers the to_png, to_gif, to_jpg and to_image methods

Options:

* xdim          -
* ydim          - 2D only
* height        - 1D only
* margin        -
* foreground    - RMagick "colorspec"
* background    - ^

Instance Attribute Summary collapse

Attributes inherited from Outputter

#barcode

Instance Method Summary collapse

Methods inherited from Outputter

#boolean_groups, #booleans, #encoding, #initialize, register, #two_dimensional?

Constructor Details

This class inherits a constructor from Barby::Outputter

Instance Attribute Details

#background ⇒ Object 



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 159

def background
  @background || 'white'
end

#foreground ⇒ Object 



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 155

def foreground
  @foreground || 'black'
end

#height ⇒ Object

The height of the barcode in px For 2D barcodes this is the number of “lines” * ydim



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 113

def height
  barcode.two_dimensional? ? (ydim * encoding.length) : (@height || 100)
end

#margin ⇒ Object

The margin of each edge surrounding the barcode in pixels



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

def margin
  @margin || 10
end

#xdim ⇒ Object

X dimension. 1X == 1px



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 128

def xdim
  @xdim || 1
end

#ydim ⇒ Object

Y dimension. Only for 2D codes



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 133

def ydim
  @ydim || xdim
end

Instance Method Details

#full_height ⇒ Object

The height of the image. This is the height of the barcode + the top and bottom margin



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

def full_height
  height + (margin * 2)
end

#full_width ⇒ Object

The full width of the image. This is the width of the barcode + the left and right margin



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 144

def full_width
  width + (margin * 2)
end

#length ⇒ Object

Number of modules (xdims) on the x axis



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 123

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

#to_blob(format, *a) ⇒ Object 



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 41

def to_blob(format, *a)
  img = to_image(*a)
  blob = img.to_blob{|i| i.format = format }

  #Release the memory used by RMagick explicitly. Ruby's GC
  #isn't aware of it and can't clean it up automatically
  img.destroy! if img.respond_to?(:destroy!)

  blob
end

#to_gif(*a) ⇒ Object

Returns a string containint a GIF image



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 32

def to_gif(*a)
  to_blob('gif', *a)
end

#to_image(opts = {}) ⇒ Object

Returns an instance of Magick::Image



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 53

def to_image(opts={})
  with_options opts do
    b = background #Capture locally because Magick::Image.new block uses instance_eval
    canvas = Magick::Image.new(full_width, full_height){ self.background_color = b }
    bars = Magick::Draw.new
    bars.fill = foreground

    x1 = margin
    y1 = margin

    if barcode.two_dimensional?
      encoding.each do |line|
        line.split(//).map{|c| c == '1' }.each do |bar|
          if bar
            x2 = x1+(xdim-1)
            y2 = y1+(ydim-1)
            # For single pixels use point
            if x1 == x2 && y1 == y2
              bars.point(x1,y1)
            else
              # For single pixel lines, use line
              if x1 == x2
                bars.line(x1, y1, x1, y2)
              elsif y1 == y2
                bars.line(x1, y1, x2, y1)
              else
                bars.rectangle(x1, y1, x2, y2)
              end
            end
          end
          x1 += xdim
        end
        x1 = margin
        y1 += ydim
      end
    else
      booleans.each do |bar|
        if bar
          x2 = x1+(xdim-1)
          y2 = y1+(height-1)
          # For single pixel width, use line
          if x1 == x2
            bars.line(x1, y1, x1, y2)
          else
            bars.rectangle(x1, y1, x2, y2)
          end
        end
        x1 += xdim
      end
    end

    bars.draw(canvas)

    canvas
  end
end

#to_jpg(*a) ⇒ Object

Returns a string containing a JPEG image



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 37

def to_jpg(*a)
  to_blob('jpg', *a)
end

#to_png(*a) ⇒ Object

Returns a string containing a PNG image



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

def to_png(*a)
  to_blob('png', *a)
end

#width ⇒ Object

The width of the barcode in px



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# File 'lib/barby/outputter/rmagick_outputter.rb', line 118

def width
  length * xdim
end