Class: Barby::SvgOutputter

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

Overview

Renders the barcode to a simple SVG image using pure ruby

Registers the to_svg, bars_to_path, and bars_to_rects method

Bars can be rendered as a stroked path or as filled rectangles. Path generally yields smaller files, but this doesn’t render cleanly in Firefox 3 for odd xdims. My guess is that the renderer tries to put half a pixel on one side of the path and half on the other, leading to fuzzy dithering instead of sharp, clean b&w.

Therefore, default behavior is to use a path for even xdims, and rectangles for odd. This can be overridden by calling with explicit :use => ‘rects’ or :use => ‘path’ options.

Instance Attribute Summary collapse

Attributes inherited from Outputter

#barcode

Instance Method Summary collapse

Methods inherited from Outputter

#initialize, register

Constructor Details

This class inherits a constructor from Barby::Outputter

Instance Attribute Details

#bmargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 164

def bmargin
  @bmargin || _ymargin
end

#height ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 132

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

#lmargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 152

def lmargin
  @lmargin || _xmargin
end

#margin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 178

def margin
  return nil if @ymargin || @xmargin || @tmargin || @bmargin || @lmargin || @rmargin
  _margin
end

#rmargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 156

def rmargin
  @rmargin || _xmargin
end

#title ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 123

def title
  @title || barcode.to_s
end

#tmargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 160

def tmargin
  @tmargin || _ymargin
end

#xdim ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 144

def xdim
  @xdim || 1
end

#xmargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 168

def xmargin
  return nil if @lmargin || @rmargin
  _margin
end

#ydim ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 148

def ydim
  @ydim || xdim
end

#ymargin ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 173

def ymargin
  return nil if @tmargin || @bmargin
  _margin
end

Instance Method Details

#bars_to_path(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 84

def bars_to_path(opts={})
  with_options opts do
    %Q|<path stroke="black" stroke-width="#{xdim}" d="#{bars_to_path_data(opts)}" />|
  end
end

#bars_to_path_data(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 91

def bars_to_path_data(opts={})
  path_data = ''
  with_options opts do
    x, y = lmargin+(xdim/2), tmargin

    if barcode.two_dimensional?
      booleans.each do |line|
        line.each do |bar|
          if bar
            path_data << "M#{x} #{y}V #{y+ydim}"
          end
          x += xdim
        end
        y += ydim
        x = lmargin+(xdim/2)
      end

    else
      booleans.each do |bar|
        if bar
          path_data << "M#{x} #{y}V#{y+height}"
        end
        x += xdim
      end

    end
  end # with_options

  path_data
end

#bars_to_rects(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 50

def bars_to_rects(opts={})
  rects = ''
  with_options opts do
    x, y = lmargin, tmargin

    if barcode.two_dimensional?
      boolean_groups.each do |line|
        line.each do |bar, amount|
          bar_width = xdim * amount
          if bar
            rects << %Q|<rect x="#{x}" y="#{y}" width="#{bar_width}px" height="#{ydim}px" />\n|
          end
          x += bar_width
        end
        y += ydim
        x = lmargin
      end

    else
      boolean_groups.each do |bar, amount|
        bar_width = xdim * amount
        if bar
          rects << %Q|<rect x="#{x}" y="#{y}" width="#{bar_width}px" height="#{height}px" />\n|
        end
        x += bar_width
      end

    end
  end # with_options

  rects
end

#full_height ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 140

def full_height
  height + tmargin + bmargin
end

#full_width ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 136

def full_width
  width + lmargin + rmargin
end

#length ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 183

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

#svg_height(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 192

def svg_height(opts={})
  opts[:rot] ? full_width : full_height
end

#svg_width(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 188

def svg_width(opts={})
  opts[:rot] ? full_height : full_width
end

#to_svg(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 25

def to_svg(opts={})
  with_options opts do
    case opts[:use]
      when 'rects' then bars = bars_to_rects
      when 'path'  then bars = bars_to_path
    else
      xdim_odd = (xdim % 2 == 1)
      bars = xdim_odd ? bars_to_rects : bars_to_path
    end

    <<-"EOT"
<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="#{svg_width(opts)}px" height="#{svg_height(opts)}px" viewBox="0 0 #{svg_width(opts)} #{svg_height(opts)}" version="1.1">
<title>#{escape title}</title>
<g id="canvas" #{transform(opts)}>
<rect x="0" y="0" width="#{full_width}px" height="#{full_height}px" fill="white" />
<g id="barcode" fill="black">
#{bars}
</g></g>
</svg>
EOT
  end
end

#transform(opts = {}) ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 197

def transform(opts={})
  opts[:rot] ? %Q|transform="rotate(-90) translate(-#{full_width}, 0)"| : nil
end

#width ⇒ Object 



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# File 'lib/barby/outputter/svg_outputter.rb', line 128

def width
  length * xdim
end