Class: Barby::PngOutputter

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

Overview

Renders the barcode to a PNG image using chunky_png (gem install chunky_png)

Registers the to_png, to_datastream and to_canvas methods

Options:

* xdim:         X dimension - bar width                                           [1]
* ydim:         Y dimension - bar height (2D only)                                [1]
* height:       Height of bars (1D only)                                          [100]
* margin:       Size of margin around barcode                                     [0]
* foreground:   Foreground color (see ChunkyPNG::Color - can be HTML color name)  [black]
* background:   Background color (see ChunkyPNG::Color - can be HTML color name)  [white]

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

#height ⇒ Object 



86
87
88
 
# File 'lib/barby/outputter/png_outputter.rb', line 86

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

#margin ⇒ Object 



106
107
108
 
# File 'lib/barby/outputter/png_outputter.rb', line 106

def margin
  @margin || 10
end

#xdim ⇒ Object 



98
99
100
 
# File 'lib/barby/outputter/png_outputter.rb', line 98

def xdim
  @xdim || 1
end

#ydim ⇒ Object 



102
103
104
 
# File 'lib/barby/outputter/png_outputter.rb', line 102

def ydim
  @ydim || xdim
end

Instance Method Details

#background ⇒ Object 



119
120
121
 
# File 'lib/barby/outputter/png_outputter.rb', line 119

def background
  @background || ChunkyPNG::Color::WHITE
end

#background=(c) ⇒ Object 



111
112
113
114
115
116
117
 
# File 'lib/barby/outputter/png_outputter.rb', line 111

def background=(c)
  @background = if c.is_a?(String) || c.is_a?(Symbol)
                  ChunkyPNG::Color.html_color(c.to_sym)
                else
                  c
                end
end

#foreground ⇒ Object 



131
132
133
 
# File 'lib/barby/outputter/png_outputter.rb', line 131

def foreground
  @foreground || ChunkyPNG::Color::BLACK
end

#foreground=(c) ⇒ Object 



123
124
125
126
127
128
129
 
# File 'lib/barby/outputter/png_outputter.rb', line 123

def foreground=(c)
  @foreground = if c.is_a?(String) || c.is_a?(Symbol)
                  ChunkyPNG::Color.html_color(c.to_sym)
                else
                  c
                end
end

#full_height ⇒ Object 



94
95
96
 
# File 'lib/barby/outputter/png_outputter.rb', line 94

def full_height
  height + (margin * 2)
end

#full_width ⇒ Object 



90
91
92
 
# File 'lib/barby/outputter/png_outputter.rb', line 90

def full_width
  width + (margin * 2)
end

#length ⇒ Object 



136
137
138
 
# File 'lib/barby/outputter/png_outputter.rb', line 136

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

#to_datastream(*a) ⇒ Object

Create a ChunkyPNG::Datastream containing the barcode image

:constraints - Value is passed on to ChunkyPNG::Image#to_datastream

E.g. to_datastream(:constraints => {:color_mode => ChunkyPNG::COLOR_GRAYSCALE})



70
71
72
73
 
# File 'lib/barby/outputter/png_outputter.rb', line 70

def to_datastream(*a)
  constraints = a.first && a.first[:constraints] ? [a.first[:constraints]] : []
  to_image(*a).to_datastream(*constraints)
end

#to_image(opts = {}) ⇒ Object

Creates a ChunkyPNG::Image object and renders the barcode on it



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

def to_image(opts={})
  with_options opts do
    canvas = ChunkyPNG::Image.new(full_width, full_height, background)

    if barcode.two_dimensional?
      x, y = margin, margin
      booleans.each do |line|
        line.each do |bar|
          if bar
            x.upto(x+(xdim-1)) do |xx|
              y.upto y+(ydim-1) do |yy|
                canvas[xx,yy] = foreground
              end
            end
          end
          x += xdim
        end
        y += ydim
        x = margin
      end
    else
      x, y = margin, margin
      booleans.each do |bar|
        if bar
          x.upto(x+(xdim-1)) do |xx|
            y.upto y+(height-1) do |yy|
              canvas[xx,yy] = foreground
            end
          end
        end
        x += xdim
      end
    end

    canvas
  end
end

#to_png(*a) ⇒ Object

Renders the barcode to a PNG image



77
78
79
 
# File 'lib/barby/outputter/png_outputter.rb', line 77

def to_png(*a)
  to_datastream(*a).to_s
end

#width ⇒ Object 



82
83
84
 
# File 'lib/barby/outputter/png_outputter.rb', line 82

def width
  length * xdim
end