Class: RQRCode::QRCode

Inherits:
Object
  • Object
show all
Defined in:
lib/rqrcode/qrcode/qr_code.rb

Overview

Creation

QRCode objects expect only one required constructor parameter and an optional hash of any other. Here’s a few examples:

qr = RQRCode::QRCode.new('hello world')
qr = RQRCode::QRCode.new('hello world', :size => 1, :level => :m )

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string, *args) ⇒ QRCode

Expects a string to be parsed in, other args are optional

# string - the string you wish to encode
# size   - the size of the qrcode (default 4)
# level  - the error correction level, can be:
   * Level :l 7%  of code can be restored
   * Level :m 15% of code can be restored
   * Level :q 25% of code can be restored
   * Level :h 30% of code can be restored (default :h)

qr = RQRCode::QRCode.new('hello world', :size => 1, :level => :m )



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 106

def initialize( string, *args )
  if !string.is_a? String
    raise QRCodeArgumentError, "The passed data is #{string.class}, not String"
  end

  options               = args.extract_options!
  level                 = (options[:level] || :h).to_sym

  if !QRERRORCORRECTLEVEL.has_key?(level)
    raise QRCodeArgumentError, "Unknown error correction level `#{level.inspect}`"
  end

  @data                 = string

  mode                  = QRAlphanumeric.valid_data?( @data ) ? :mode_alpha_numk : :mode_8bit_byte

  max_size_array        = QRMAXDIGITS[level][mode]
  size                  = options[:size] || smallest_size_for(string, max_size_array)
  
  if size > QRUtil.max_size
    raise QRCodeArgumentError, "Given size greater than maximum possible size of #{QRUtil.max_size}"
  end

  @error_correct_level  = QRERRORCORRECTLEVEL[level]
  @version              = size
  @module_count         = @version * 4 + QRPOSITIONPATTERNLENGTH
  @modules              = Array.new( @module_count )
  @data_list            = (mode == :mode_alpha_numk) ? QRAlphanumeric.new( @data ) : QR8bitByte.new( @data )
  @data_cache           = nil
  self.make
end

Instance Attribute Details

#error_correction_level ⇒ Object (readonly)

Returns the value of attribute error_correction_level.



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 91

def error_correction_level
  @error_correction_level
end

#module_count ⇒ Object (readonly)

Returns the value of attribute module_count.



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 91

def module_count
  @module_count
end

#modules ⇒ Object (readonly)

Returns the value of attribute modules.



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 91

def modules
  @modules
end

#version ⇒ Object (readonly)

Returns the value of attribute version.



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 91

def version
  @version
end

Instance Method Details

#is_dark(row, col) ⇒ Object Also known as: dark?

is_dark is called with a col and row parameter. This will return true or false based on whether that coordinate exists in the matrix returned. It would normally be called while iterating through modules. A simple example would be:

instance.is_dark( 10, 10 ) => true



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 146

def is_dark( row, col )
  if !row.between?(0, @module_count - 1) || !col.between?(0, @module_count - 1)
    raise QRCodeRunTimeError, "Invalid row/column pair: #{row}, #{col}"
  end
  @modules[row][col]
end

#to_s(*args) ⇒ Object

This is a public method that returns the QR Code you have generated as a string. It will not be able to be read in this format by a QR Code reader, but will give you an idea if the final outout. It takes two optional args :true and :false which are there for you to choose how the output looks. Here’s an example of it’s use:

instance.to_s =>
xxxxxxx x  x x   x x  xx  xxxxxxx
x     x  xxx  xxxxxx xxx  x     x
x xxx x  xxxxx x       xx x xxx x

instance._to_s( :dark => 'E', :light => 'Q') =>
EEEEEEEQEQQEQEQQQEQEQQEEQQEEEEEEE
EQQQQQEQQEEEQQEEEEEEQEEEQQEQQQQQE
EQEEEQEQQEEEEEQEQQQQQQQEEQEQEEEQE



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# File 'lib/rqrcode/qrcode/qr_code.rb', line 172

def to_s( *args )
  options                = args.extract_options!
  dark                   = options[:dark] || options[:true] || 'x'
  light                  = options[:light] || options[:false] || ' '
  quiet_zone_size        = options[:quiet_zone_size] || 0

  rows = []

  @modules.each do |row|
    cols = light * quiet_zone_size
    row.each do |col|
      cols += (col ? dark : light)
    end
    rows << cols
  end
  
  quiet_zone_size.times do
    rows.unshift(light * (rows.first.length / light.size))
    rows << light * (rows.first.length / light.size)
  end 
  rows.join("\n")
end