Class: RQRCode::QRCode

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

Instance Method Summary collapse

Instance Method Details

#to_svg(*args) ⇒ Object 



9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
 
# File 'lib/rqrcode_to_svg.rb', line 9

def to_svg( *args )
  
  # Options.
  
  # The :border option sets the border around the QR code.
    # true adds a default border, with a size of four QR Code-points.
    # false adds no border. This is the default.
    # Or, enter a number (as a measure of QR Code-points) to set your own custom border size.
    
  # The :px option determines the size of each QR Code-point in pixels. The default is 4 pixels.
  # Throughout the conversion, we'll multiply each QR Code-point by this :px value.
  
  # The :file option sets the path to which the SVG file will be written. 
    # If set to false (default), the SVG XML will be returned as a string.
    
  # The :namespace option is a boolean that adds the "svg" XML namespace prefix. Default is false.
  
  # The :indent option is used to pretty print the XML. Defaults to false.
    # false gives a tag soup with no line breaks.
    # true adds line breaks and indents each child element by two spaces.
    # A String object adds line breaks and will be used as the literal indentation.
    # A number adds line breaks and will be interpreted as the number of spaces to indent.
  
  options = args.extract_options!
  border = options[:border] || false
  px_multiplier = options[:px] || 4
  file = options[:file] || false
  namespace = options[:namespace] || false
  indent = options[:indent] || false
  
  # The following case evaluates the :border option. Goal: to set the length of the border.
  border_length = 0
  case border
    when TrueClass
      border_length = 4 * px_multiplier
    when String, Numeric
      border_length = border.to_i * px_multiplier
  end
  
  # The following case evaluates the :indent option. Goal: to pretty print the XML if desired.
  indentation = String.new
  case indent
    when TrueClass
      indentation = " " * 2
    when String
      indentation = indent
    when Numeric
      indentation = " " * indent
  end
  
  # qr_side_length calculates the side length of the QR code *without the border*.
  qr_side_length = px_multiplier * @module_count
  
  # total_side_length calculates the side length of the QR code with the border included.
  total_side_length = qr_side_length + (border_length * 2)
  
  # Find all of the "dark" points within the QR code.
  # For each dark point, add a <rect/> SVG XML element (as a String) to the svg_squares array.
  svg_squares = Array.new
  @modules.each_index do |y|
    @modules.each_index do |x|
      if dark?(y,x)
        svg_squares.push("#{indentation}<#{"svg:" if namespace}rect x='#{(border_length + (px_multiplier * x))}px' y='#{(border_length + (px_multiplier * y))}px' width='#{px_multiplier}px' height='#{px_multiplier}px' style='fill:rgb(0,0,0)'/>#{"\n" if indent}")
      end
    end
  end
  
  # Constuct the SVG XML. 
  svg = "<#{"svg:" if namespace}svg xmlns#{":svg" if namespace}='http://www.w3.org/2000/svg' version='1.1' baseProfile='full' width='#{total_side_length}px' height='#{total_side_length}px'>#{"\n" if indent}#{svg_squares.join}</#{"svg:" if namespace}svg>"
  
  # Checks the file option.
  # If a path is given, write the SVG to the file and return the path.
  # If a path is not given, return the SVG as a string.
  if file
    File.open(file, 'w') do |file| 
      file.write(("<?xml version='1.0' encoding='UTF-8'?>\n" + svg))
    end
    return file
  else
    return svg
  end
  
end