Class: LiquidCode

Inherits:
Object
  • Object
show all
Defined in:
lib/liquid_code.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(qr) ⇒ LiquidCode 



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# File 'lib/liquid_code.rb', line 6

def initialize(qr)
  unless qr.is_a?(RQRCode::QRCode)
    # convert input's string represantation to qr_code
    qr = RQRCode::QRCode.new( qr.to_s, :size => LiquidCode.minimum_qr_size_from_string(qr.to_s), :level => :h )
  end

  @qr = qr

end

Class Method Details

.minimum_qr_size_from_string(str) ⇒ Object 



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# File 'lib/liquid_code.rb', line 106

def LiquidCode.minimum_qr_size_from_string(str)
  sizes = [7, 14, 24, 34, 44, 58, 64, 84, 98, 119, 137, 155, 177, 194]
  sizes.each_index do |i|
    if str.length <= sizes[i]
      return i+1
    end
  end
  return -1
end

Instance Method Details

#as_png(bgcolor = 'white', fgcolor = 'black', fgcolorwhite = true, block_size = 16) ⇒ Object 



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# File 'lib/liquid_code.rb', line 15

def as_png(bgcolor='white', fgcolor='black', fgcolorwhite=true, block_size=16)
  image_size=((@qr.modules.size+1) * block_size)
  canvas_image = Magick::ImageList.new
  canvas_image.new_image(image_size, image_size) do
    self.background_color = bgcolor
    self.format = "png"
  end

  canvas = Magick::Draw.new

  draw_to_canvas(bgcolor, fgcolor, fgcolorwhite, canvas, 0, 0, block_size)

  canvas.draw(canvas_image)
  canvas_image.to_blob
end

#draw_to_canvas(bgcolor, fgcolor, fgcolorwhite, canvas, ox, oy, bs) ⇒ Object 



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# File 'lib/liquid_code.rb', line 31

def draw_to_canvas(bgcolor, fgcolor, fgcolorwhite, canvas, ox, oy, bs)

  image_size=@qr.modules.size * bs
  canvas.stroke(bgcolor)
  canvas.fill(bgcolor)
  canvas.rectangle(ox, oy, ox + image_size, oy + image_size)
  canvas.stroke(fgcolor)
  canvas.fill(fgcolor)
  canvas.fill_opacity(1)
  canvas.stroke_width(1)

  # half block size
  hbs = bs/2

  is_dark = lambda { |x, y|
    begin
      return ((@qr.is_dark(y, x) and fgcolorwhite) or ((not @qr.is_dark(y, x)) and (not fgcolorwhite)))
    rescue IndexError, RQRCode::QRCodeRunTimeError
      return (not fgcolorwhite)
    end
  }

  @qr.modules.each_index do |x|
    @qr.modules.each_index do |y|
      if is_dark.call(x, y)
        canvas.roundrectangle(ox+(x * bs), oy+(y * bs), ox+((x+1) * bs), oy+((y+1) * bs), hbs, hbs)
        if (is_dark.call(x, y+1))
          canvas.rectangle(ox+(x * bs), oy+(y * bs)+hbs, ox+((x+1) * bs), oy+((y+1) * bs)+hbs)
        end
        if (is_dark.call(x+1, y))
          canvas.rectangle(ox+(x * bs)+hbs, oy+(y * bs), ox+((x+1) * bs)+hbs, oy+((y+1) * bs))
        end

      end
    end
  end

  @qr.modules.each_index do |x|
    @qr.modules.each_index do |y|
      if (not is_dark.call(x, y))

        # I am white

        # upper right corner should be round
        if (is_dark.call(x+1, y) and is_dark.call(x, y-1) and is_dark.call(x+1, y-1))
          canvas.rectangle(ox+(x * bs)+hbs, oy+(y * bs), ox+((x+1) * bs), oy+((y) * bs)+hbs)
        end

        # lower right corner should be round
        if (is_dark.call(x+1, y) and is_dark.call(x+1, y+1) and is_dark.call(x, y+1))
          canvas.rectangle(ox+(x * bs)+hbs, oy+(y * bs)+hbs, ox+((x+1) * bs), oy+((y+1) * bs))
        end

        # lower left corner should be round
        if (is_dark.call(x-1, y) and is_dark.call(x-1, y+1) and is_dark.call(x, y+1))
          canvas.rectangle(ox+(x * bs), oy+(y * bs)+hbs, ox+(x * bs)+hbs, oy+((y+1) * bs))
        end

        # upper left corner should be round
        if (is_dark.call(x-1, y-1) and is_dark.call(x-1, y) and is_dark.call(x, y-1))
          canvas.rectangle(ox+(x * bs), oy+(y * bs), ox+(x * bs)+hbs, oy+(y * bs)+hbs)
        end

        canvas.fill(bgcolor)
        canvas.stroke(bgcolor)
        canvas.roundrectangle(ox+(x * bs)+1, oy+(y * bs)+1, ox+((x+1) * bs)-1, oy+((y+1) * bs)-1, hbs, hbs)
        canvas.stroke(fgcolor)
        canvas.fill(fgcolor)

      end
    end
  end

end