module Qr4r

Constants

SIZE_RESTRICTIONS: These come from rqrcode_core - read github.com/whomwah/rqrcode_core for more information
VERSION

Public Class Methods

encode(str, outfile, *rest) click to toggle source

# File lib/qr4r.rb, line 8
def self.encode(str, outfile, *rest)
  opts = rest[0] unless rest.empty?
  opts ||= {}
  opts[:size] = compute_size(str) unless opts[:size]
  opts[:pixel_size] = 3 unless opts[:pixel_size]
  qr_code, data = build_qr_code(str, opts)
  create_image(qr_code, data, outfile, opts)
end

Private Class Methods

build_qr_code(str, opts) click to toggle source

# File lib/qr4r.rb, line 20
def build_qr_code(str, opts)
  qr = RQRCodeCore::QRCode.new(str, opts)
  data = [].tap do |px|
    qr.modules.each_index do |x|
      qr.modules.each_index do |y|
        if qr.checked?(x, y)
          3.times { px << 0 }
        else
          3.times { px << 255 }
        end
      end
    end
  end
  [qr, data]
end

compute_size(str) click to toggle source

# File lib/qr4r.rb, line 53
def compute_size(str)
  slen = str.size
  ii = 0
  while ii < SIZE_RESTRICTIONS.length
    break if slen < SIZE_RESTRICTIONS[ii]

    ii += 1
  end
  if ii > 10
    raise "Your string is too big for this encoder.  It should be less than #{SIZE_RESTRICTIONS.last} characters"
  end

  ii
end

create_image(qr_code, data, outfile, opts) click to toggle source

# File lib/qr4r.rb, line 36
def create_image(qr_code, data, outfile, opts)
  MojoMagick.convert do |c|
    d = data.pack "C" * data.size
    c.blob(d, format: :rgb, depth: 8, size: format("%dx%d", qr_code.modules.size, qr_code.modules.size))
    if opts[:pixel_size]
      wd = qr_code.modules.size * opts[:pixel_size].to_i
      c.scale format("%dx%d", wd, wd)
    end
    if opts[:border]
      border = opts[:border].to_i
      c.bordercolor "white"
      c.border format("%dx%d", border, border)
    end
    c.file outfile
  end
end