GraphViz wrapper to make animation gif

graphaz.rb

require "graphviz"
require "RMagick"

class GraphAz
  attr_accessor :graph, :nodes, :edges, :gnode, :gedge
  def initialize(name= :G, *opt, &blk)
    @graph = GraphViz.new(name, *opt, &blk)
    @gnode, @gedge = @graph.node, @graph.edge
    @nodes, @edges = [], {}
    @@lap, @laps = 0, []
  end

  def [](attr)
    @graph[attr]
  end
  
  def []=(attr, val)
    @graph[attr] = val
  end
  
  def add(s, attrs={})
    names = s.split(/\s*=>\s*/).map { |n| n.sub(/^:/, '') }
    names.map! { |name| @nodes << node = @graph.add_node(name, attrs); node }
    names.each_cons(2) do |a, b|
      @edges["#{a.name}_#{b.name}"] = @graph.add_edge(a, b)
    end
    @graph
  end
  
  def node(*nodes, opts)
    nodes.each do |node|
      opts.each { |attr, val| @graph.get_node(node)[attr] = val  }
    end
  end
  
  def edge(*edges, opts)
    @edges.each do |name, edge|
      next unless edges.empty? or edges.include?(name)
      opts.each { |attr, val| edge.set { |e| e.send(attr, val) } }
    end
  end

  def print_graph(args={}, &blk)
    @graph.output(args, &blk)
  end

  def lap(args={:png => "out#{@@lap}.png"}, &blk)
    print_graph(args, &blk)
    @@lap += 1
    @laps << args[:png]
  end
  
  def write(opts={})
    puts 'processing...'
    opts = {:delay => 50, :filename => 'out.gif', :delete => true}.merge(opts)
    list = Magick::ImageList.new(*@laps)
    list.delay = opts[:delay]
    list.write(opts[:filename])
    puts "'#{opts[:filename]}' created!"
  rescue Exception => e
    puts "Failed attempt to create animation gif : #{e}"
  ensure
    @laps.each { |f| File.delete(f) if opts[:delete] }
    @laps.clear
  end
end

if __FILE__ == $0
  ga = GraphAz.new(:Dijkstra, :type => 'graph')

  ga['rankdir'] = 'LR'
  ga['label']   = "Dijkstra's Algorithm"
  ga['bgcolor'] = 'whitesmoke'
  routes = [
    ':S => :A => :G',
    ':S => :B => :D => :G',
    ':S => :C => :D',
    ':A => :B => :C' 
  ]

  edge_labels = {
    '2' => ['A_B', 'S_C', 'B_D'],
    '3' => ['B_C'],
    '4' => ['S_B', 'D_G'],
    '5' => ['S_A'],
    '6' => ['C_D', 'A_G']
  }

  routes.each { |route| ga.add route }
  edge_labels.each { |label, edges| ga.edge(*edges, :label => label) }
  ga.lap

  color = 'blueviolet'

  ga.node('S', :style => 'filled', :fillcolor => color)
  ga.lap
  ga.edge('S_B', :color => color)
  ga.lap
  ga.node('B', :style => 'filled', :fillcolor => color)
  ga.lap
  ga.edge('B_D', :color => color)
  ga.lap
  ga.node('D', :style => 'filled', :fillcolor => color)
  ga.lap
  ga.edge('D_G', :color => color)
  ga.lap
  ga.node('G', :style => 'filled', :fillcolor => color)
  ga.lap

  ga.write
end

rubyclass_graph.rb

require "graphaz"

ga = GraphAz.new(:RubyClasses)
ga[:label] = "Ruby Class Map"
ga[:fontsize] = 20
ga[:fontcolor] = 'darkviolet'
ga[:bgcolor] = "whitesmoke"

gnode_set = {
  :shape => 'Mrecord',
  :style => 'filled',
  :height => 0.8,
  :width => 1,
  :fontcolor => 'white'
}

gnode_set.each { |attr, val| ga.gnode[attr] = val }
ga.gedge[:style] = 'dotted'

obj, mod, cla, sta, ins_a, ins_b, ins_c, ker, modA, modB =
  "Object\nclass", "Module\nclass", "Class\nclass", "Standard\nclass", "Instance a", "Instance b", "Instance c", "Kernel\nmodule", "module A", "module B"
  
routes = [
  "#{obj} => #{mod} => #{cla}",
  "#{cla} => #{sta}",
  "#{cla} => #{obj}",
  "#{cla} => #{mod}",
  "#{sta} => #{ins_a}",
  "#{sta} => #{ins_b}",
  "#{sta} => #{ins_c}",
  "#{mod} => #{ker}",
  "#{mod} => #{modA}",
  "#{mod} => #{modB}",
  "#{ker} => #{obj}"
]

def fill_with(color)
  {:style => 'filled', :fillcolor => color }
end

routes.each { |route| ga.add route }

ga.node( ins_a, ins_b, ins_c, modA, modB, ker, :height => 0.5, :width => 0.7, :shape => 'ellipse' )
ga.lap

ga.node( cla, fill_with(:steelblue) )
ga.lap

ga.edge( "#{cla}_#{mod}", "#{cla}_#{obj}", "#{cla}_#{sta}", :style => 'bold', :color => 'steelblue' )
ga.lap

ga.node( obj, mod, sta, fill_with(:steelblue) )
ga.lap

ga.edge( "#{sta}_#{ins_a}", "#{sta}_#{ins_b}", "#{sta}_#{ins_c}", "#{mod}_#{modA}", "#{mod}_#{modB}", "#{mod}_#{ker}", :style => 'bold', :color => 'steelblue' )
ga.lap

ga.node( ins_a, ins_b, ins_c, modA, modB, ker, fill_with(:lightblue).merge(:fontcolor => 'midnightblue') )
ga.lap

ga.edge( "#{ker}_#{obj}", :style => 'none', :color => 'darkviolet' )
ga.lap

ga.node( cla, fill_with(:steelblue) )
ga.lap

ga.node( obj, fill_with(:maroon) )
ga.lap

ga.edge( "#{obj}_#{mod}", :style => 'bold', :color => 'maroon' )
ga.lap

ga.node( mod, fill_with(:maroon) )
ga.lap

ga.edge( "#{mod}_#{cla}", :style => 'bold', :color => 'maroon' )
ga.lap

ga.node( cla, fill_with(:maroon) )
ga.lap

ga.write