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begin

  require 'zlib'

  @@__have_zlib = true

rescue

  @@__have_zlib = false

end

require 'rexml/document'

module SVG

  module Graph

    VERSION = '@ANT_VERSION@'

    # === Base object for generating SVG Graphs

    # 

    # == Synopsis

    #

    # This class is only used as a superclass of specialized charts.  Do not

    # attempt to use this class directly, unless creating a new chart type.

    #

    # For examples of how to subclass this class, see the existing specific

    # subclasses, such as SVG::Graph::Pie.

    #

    # == Examples

    #

    # For examples of how to use this package, see either the test files, or

    # the documentation for the specific class you want to use.

    #

    # * file:test/plot.rb

    # * file:test/single.rb

    # * file:test/test.rb

    # * file:test/timeseries.rb

    # 

    # == Description

    # 

    # This package should be used as a base for creating SVG graphs.

    #

    # == Acknowledgements

    #

    # Leo Lapworth for creating the SVG::TT::Graph package which this Ruby

    # port is based on.

    #

    # Stephen Morgan for creating the TT template and SVG.

    # 

    # == See

    #

    # * SVG::Graph::BarHorizontal

    # * SVG::Graph::Bar

    # * SVG::Graph::Line

    # * SVG::Graph::Pie

    # * SVG::Graph::Plot

    # * SVG::Graph::TimeSeries

    #

    # == Author

    #

    # Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>

    #

    # Copyright 2004 Sean E. Russell

    # This software is available under the Ruby license[LICENSE.txt]

    #

    class Graph

      include REXML

      # Initialize the graph object with the graph settings.  You won't

      # instantiate this class directly; see the subclass for options.

      # [width] 500

      # [height] 300

      # [show_x_guidelines] false

      # [show_y_guidelines] true

      # [show_data_values] true

      # [min_scale_value] 0

      # [show_x_labels] true

      # [stagger_x_labels] false

      # [rotate_x_labels] false

      # [step_x_labels] 1

      # [step_include_first_x_label] true

      # [show_y_labels] true

      # [rotate_y_labels] false

      # [scale_integers] false

      # [show_x_title] false

      # [x_title] 'X Field names'

      # [show_y_title] false

      # [y_title_text_direction] :bt

      # [y_title] 'Y Scale'

      # [show_graph_title] false

      # [graph_title] 'Graph Title'

      # [show_graph_subtitle] false

      # [graph_subtitle] 'Graph Sub Title'

      # [key] true,

      # [key_position] :right, # bottom or righ

      # [font_size] 12

      # [title_font_size] 16

      # [subtitle_font_size] 14

      # [x_label_font_size] 12

      # [x_title_font_size] 14

      # [y_label_font_size] 12

      # [y_title_font_size] 14

      # [key_font_size] 10

      # [no_css] false

      # [add_popups] false

      def initialize( config )

        @config = config

        self.top_align = self.top_font = self.right_align = self.right_font = 0

        init_with({

          :width                => 500,

          :height                => 300,

          :show_x_guidelines    => false,

          :show_y_guidelines    => true,

          :show_data_values     => true,

#          :min_scale_value      => 0,

          :show_x_labels        => true,

          :stagger_x_labels     => false,

          :rotate_x_labels      => false,

          :step_x_labels        => 1,

          :step_include_first_x_label => true,

          :show_y_labels        => true,

          :rotate_y_labels      => false,

          :stagger_y_labels     => false,

          :scale_integers       => false,

          :show_x_title         => false,

          :x_title              => 'X Field names',

          :show_y_title         => false,

          :y_title_text_direction => :bt,

          :y_title              => 'Y Scale',

          :show_graph_title      => false,

          :graph_title          => 'Graph Title',

          :show_graph_subtitle  => false,

          :graph_subtitle        => 'Graph Sub Title',

          :key                  => true, 

          :key_position          => :right, # bottom or right

          :font_size            =>12,

          :title_font_size      =>16,

          :subtitle_font_size   =>14,

          :x_label_font_size    =>12,

          :x_title_font_size    =>14,

          :y_label_font_size    =>12,

          :y_title_font_size    =>14,

          :key_font_size        =>10,

          :no_css               =>false,

          :add_popups           =>false,

        })

                                set_defaults if respond_to? :set_defaults

        init_with config

      end

      # This method allows you do add data to the graph object.

      # It can be called several times to add more data sets in.

      #

      #   data_sales_02 = [12, 45, 21];

      #   

      #   graph.add_data({

      #     :data => data_sales_02,

      #     :title => 'Sales 2002'

      #   })

      def add_data conf

        @data = [] unless defined? @data

        if conf[:data] and conf[:data].kind_of? Array

          @data << conf

        else

          raise "No data provided by #{conf.inspect}"

        end

      end

      # This method removes all data from the object so that you can

      # reuse it to create a new graph but with the same config options.

      #

      #   graph.clear_data

      def clear_data 

        @data = []

      end

      # This method processes the template with the data and

      # config which has been set and returns the resulting SVG.

      #

      # This method will croak unless at least one data set has

      # been added to the graph object.

      #

      #   print graph.burn

      def burn

        raise "No data available" unless @data.size > 0

        calculations if respond_to? :calculations

        start_svg

        calculate_graph_dimensions

        @foreground = Element.new( "g" )

        draw_graph

        draw_titles

        draw_legend

        draw_data

        @graph.add_element( @foreground )

        style

        data = ""

        @doc.write( data, 0 )

        if @config[:compress]

          if @@__have_zlib

            inp, out = IO.pipe

            gz = Zlib::GzipWriter.new( out )

            gz.write data

            gz.close

            data = inp.read

          else

            data << "<!-- Ruby Zlib not available for SVGZ -->";

          end

        end

        return data

      end

      #   Set the height of the graph box, this is the total height

      #   of the SVG box created - not the graph it self which auto

      #   scales to fix the space.

      attr_accessor :height

      #   Set the width of the graph box, this is the total width

      #   of the SVG box created - not the graph it self which auto

      #   scales to fix the space.

      attr_accessor :width

      #   Set the path to an external stylesheet, set to '' if

      #   you want to revert back to using the defaut internal version.

      #

      #   To create an external stylesheet create a graph using the

      #   default internal version and copy the stylesheet section to

      #   an external file and edit from there.

      attr_accessor :style_sheet

      #   (Bool) Show the value of each element of data on the graph

      attr_accessor :show_data_values

      #   The point at which the Y axis starts, defaults to '0',

      #   if set to nil it will default to the minimum data value.

      attr_accessor :min_scale_value

      #   Whether to show labels on the X axis or not, defaults

      #   to true, set to false if you want to turn them off.

      attr_accessor :show_x_labels

      #   This puts the X labels at alternative levels so if they

      #   are long field names they will not overlap so easily.

      #   Default it false, to turn on set to true.

      attr_accessor :stagger_x_labels

      #   This puts the Y labels at alternative levels so if they

      #   are long field names they will not overlap so easily.

      #   Default it false, to turn on set to true.

      attr_accessor :stagger_y_labels

      #   This turns the X axis labels by 90 degrees.

      #   Default it false, to turn on set to true.

      attr_accessor :rotate_x_labels

      #   This turns the Y axis labels by 90 degrees.

      #   Default it false, to turn on set to true.

      attr_accessor :rotate_y_labels

      #   How many "steps" to use between displayed X axis labels,

      #   a step of one means display every label, a step of two results

      #   in every other label being displayed (label <gap> label <gap> label),

      #   a step of three results in every third label being displayed

      #   (label <gap> <gap> label <gap> <gap> label) and so on.

      attr_accessor :step_x_labels

      #   Whether to (when taking "steps" between X axis labels) step from 

      #   the first label (i.e. always include the first label) or step from

      #   the X axis origin (i.e. start with a gap if step_x_labels is greater

      #   than one).

      attr_accessor :step_include_first_x_label

      #   Whether to show labels on the Y axis or not, defaults

      #   to true, set to false if you want to turn them off.

      attr_accessor :show_y_labels

      #   Ensures only whole numbers are used as the scale divisions.

      #   Default it false, to turn on set to true. This has no effect if 

      #   scale divisions are less than 1.

      attr_accessor :scale_integers

      #   This defines the gap between markers on the Y axis,

      #   default is a 10th of the max_value, e.g. you will have

      #   10 markers on the Y axis. NOTE: do not set this too

      #   low - you are limited to 999 markers, after that the

      #   graph won't generate.

      attr_accessor :scale_divisions

      #   Whether to show the title under the X axis labels,

      #   default is false, set to true to show.

      attr_accessor :show_x_title

      #   What the title under X axis should be, e.g. 'Months'.

      attr_accessor :x_title

      #   Whether to show the title under the Y axis labels,

      #   default is false, set to true to show.

      attr_accessor :show_y_title

      #   Aligns writing mode for Y axis label. 

      #   Defaults to :bt (Bottom to Top).

      #   Change to :tb (Top to Bottom) to reverse.

      attr_accessor :y_title_text_direction

      #   What the title under Y axis should be, e.g. 'Sales in thousands'.

      attr_accessor :y_title

      #   Whether to show a title on the graph, defaults

      #   to false, set to true to show.

      attr_accessor :show_graph_title

      #   What the title on the graph should be.

      attr_accessor :graph_title

      #   Whether to show a subtitle on the graph, defaults

      #   to false, set to true to show.

      attr_accessor :show_graph_subtitle

      #   What the subtitle on the graph should be.

      attr_accessor :graph_subtitle

      #   Whether to show a key, defaults to false, set to

      #   true if you want to show it.

      attr_accessor :key

      #   Where the key should be positioned, defaults to

      #   :right, set to :bottom if you want to move it.

      attr_accessor :key_position

      # Set the font size (in points) of the data point labels

      attr_accessor :font_size

      # Set the font size of the X axis labels

      attr_accessor :x_label_font_size

      # Set the font size of the X axis title

      attr_accessor :x_title_font_size

      # Set the font size of the Y axis labels

      attr_accessor :y_label_font_size

      # Set the font size of the Y axis title

      attr_accessor :y_title_font_size

      # Set the title font size

      attr_accessor :title_font_size

      # Set the subtitle font size

      attr_accessor :subtitle_font_size

      # Set the key font size

      attr_accessor :key_font_size

      # Show guidelines for the X axis

      attr_accessor :show_x_guidelines

      # Show guidelines for the Y axis

      attr_accessor :show_y_guidelines

      # Do not use CSS if set to true.  Many SVG viewers do not support CSS, but

      # not using CSS can result in larger SVGs as well as making it impossible to

      # change colors after the chart is generated.  Defaults to false.

      attr_accessor :no_css

      # Add popups for the data points on some graphs

      attr_accessor :add_popups

      protected

      def sort( *arrys )

        sort_multiple( arrys )

      end

      # Overwrite configuration options with supplied options.  Used

      # by subclasses.

      def init_with config

        config.each { |key, value|

          self.send((key.to_s+"=").to_sym, value ) if respond_to? key.to_sym

        }

      end

      attr_accessor :top_align, :top_font, :right_align, :right_font

      KEY_BOX_SIZE = 12

      # Override this (and call super) to change the margin to the left

      # of the plot area.  Results in @border_left being set.

      def calculate_left_margin

        @border_left = 7

        # Check for Y labels

        max_y_label_height_px = rotate_y_labels ? 

          y_label_font_size :

          get_y_labels.max{|a,b| 

            a.to_s.length<=>b.to_s.length

          }.to_s.length * y_label_font_size * 0.6

        @border_left += max_y_label_height_px if show_y_labels

        @border_left += max_y_label_height_px + 10 if stagger_y_labels

        @border_left += y_title_font_size + 5 if show_y_title

      end

      # Calculates the width of the widest Y label.  This will be the

      # character height if the Y labels are rotated

      def max_y_label_width_px

        return font_size if rotate_y_labels

      end

      # Override this (and call super) to change the margin to the right

      # of the plot area.  Results in @border_right being set.

      def calculate_right_margin

        @border_right = 7

        if key and key_position == :right

          val = keys.max { |a,b| a.length <=> b.length }

          @border_right += val.length * key_font_size * 0.6 

          @border_right += KEY_BOX_SIZE

          @border_right += 10    # Some padding around the box

        end

      end

      # Override this (and call super) to change the margin to the top

      # of the plot area.  Results in @border_top being set.

      def calculate_top_margin

        @border_top = 5

        @border_top += title_font_size if show_graph_title

        @border_top += 5

        @border_top += subtitle_font_size if show_graph_subtitle

      end

      # Adds pop-up point information to a graph.

      def add_popup( x, y, label )

        txt_width = label.length * font_size * 0.6 + 10

        tx = (x+txt_width > width ? x-5 : x+5)

        t = @foreground.add_element( "text", {

          "x" => tx.to_s,

          "y" => (y - font_size).to_s,

          "visibility" => "hidden",

        })

        t.attributes["style"] = "fill: #000; "+

          (x+txt_width > width ? "text-anchor: end;" : "text-anchor: start;")

        t.text = label.to_s

        t.attributes["id"] = t.object_id.to_s

        @foreground.add_element( "circle", {

          "cx" => x.to_s,

          "cy" => y.to_s,

          "r" => "10",

          "style" => "opacity: 0",

          "onmouseover" => 

            "document.getElementById(#{t.object_id}).setAttribute('visibility', 'visible' )",

          "onmouseout" => 

            "document.getElementById(#{t.object_id}).setAttribute('visibility', 'hidden' )",

        })

      end

      # Override this (and call super) to change the margin to the bottom

      # of the plot area.  Results in @border_bottom being set.

      def calculate_bottom_margin

        @border_bottom = 7

        if key and key_position == :bottom

          @border_bottom += @data.size * (font_size + 5)

          @border_bottom += 10

        end

        if show_x_labels

                  max_x_label_height_px = (not rotate_x_labels) ? 

            x_label_font_size :

            get_x_labels.max{|a,b| 

              a.to_s.length<=>b.to_s.length

            }.to_s.length * x_label_font_size * 0.6

          @border_bottom += max_x_label_height_px

          @border_bottom += max_x_label_height_px + 10 if stagger_x_labels

        end

        @border_bottom += x_title_font_size + 5 if show_x_title

      end

      # Draws the background, axis, and labels.

      def draw_graph

        @graph = @root.add_element( "g", {

          "transform" => "translate( #@border_left #@border_top )"

        })

        # Background

        @graph.add_element( "rect", {

          "x" => "0",

          "y" => "0",

          "width" => @graph_width.to_s,

          "height" => @graph_height.to_s,

          "class" => "graphBackground"

        })

        # Axis

        @graph.add_element( "path", {

          "d" => "M 0 0 v#@graph_height",

          "class" => "axis",

          "id" => "xAxis"

        })

        @graph.add_element( "path", {

          "d" => "M 0 #@graph_height h#@graph_width",

          "class" => "axis",

          "id" => "yAxis"

        })

        draw_x_labels

        draw_y_labels

      end

      # Where in the X area the label is drawn

      # Centered in the field, should be width/2.  Start, 0.

      def x_label_offset( width )

        0

      end

      def make_datapoint_text( x, y, value, style="" )

        if show_data_values

          @foreground.add_element( "text", {

            "x" => x.to_s,

            "y" => y.to_s,

            "class" => "dataPointLabel",

            "style" => "#{style} stroke: #fff; stroke-width: 2;"

          }).text = value.to_s

          text = @foreground.add_element( "text", {

            "x" => x.to_s,

            "y" => y.to_s,

            "class" => "dataPointLabel"

          })

          text.text = value.to_s

          text.attributes["style"] = style if style.length > 0

        end

      end

      # Draws the X axis labels

      def draw_x_labels

        stagger = x_label_font_size + 5

        if show_x_labels

          label_width = field_width

          count = 0

          for label in get_x_labels

            if step_include_first_x_label == true then

              step = count % step_x_labels

            else

              step = (count + 1) % step_x_labels

            end

            if step == 0 then

              text = @graph.add_element( "text" )

              text.attributes["class"] = "xAxisLabels"

              text.text = label.to_s

              x = count * label_width + x_label_offset( label_width )

              y = @graph_height + x_label_font_size + 3

              t = 0 - (font_size / 2)

              if stagger_x_labels and count % 2 == 1

                y += stagger

                @graph.add_element( "path", {

                  "d" => "M#{x} #@graph_height v#{stagger}",

                  "class" => "staggerGuideLine"

                })

              end

              text.attributes["x"] = x.to_s

              text.attributes["y"] = y.to_s

              if rotate_x_labels

                text.attributes["transform"] = 

                  "rotate( 90 #{x} #{y-x_label_font_size} )"+

                  " translate( 0 -#{x_label_font_size/4} )"

                text.attributes["style"] = "text-anchor: start"

              else

                text.attributes["style"] = "text-anchor: middle"

              end

            end

            draw_x_guidelines( label_width, count ) if show_x_guidelines

            count += 1

          end

        end

      end

      # Where in the Y area the label is drawn

      # Centered in the field, should be width/2.  Start, 0.

      def y_label_offset( height )

        0

      end

      def field_width

        (@graph_width.to_f - font_size*2*right_font) /

           (get_x_labels.length - right_align)

      end

      def field_height

        (@graph_height.to_f - font_size*2*top_font) /

           (get_y_labels.length - top_align)

      end

      # Draws the Y axis labels

      def draw_y_labels

        stagger = y_label_font_size + 5

        if show_y_labels

          label_height = field_height

          count = 0

          y_offset = @graph_height + y_label_offset( label_height )

          y_offset += font_size/1.2 unless rotate_y_labels

          for label in get_y_labels

            y = y_offset - (label_height * count)

            x = rotate_y_labels ? 0 : -3

            if stagger_y_labels and count % 2 == 1

              x -= stagger

              @graph.add_element( "path", {

                "d" => "M#{x} #{y} h#{stagger}",

                "class" => "staggerGuideLine"

              })

            end

            text = @graph.add_element( "text", {

              "x" => x.to_s,

              "y" => y.to_s,

              "class" => "yAxisLabels"

            })

            text.text = label.to_s

            if rotate_y_labels

              text.attributes["transform"] = "translate( -#{font_size} 0 ) "+

                "rotate( 90 #{x} #{y} ) "

              text.attributes["style"] = "text-anchor: middle"

            else

              text.attributes["y"] = (y - (y_label_font_size/2)).to_s

              text.attributes["style"] = "text-anchor: end"

            end

            draw_y_guidelines( label_height, count ) if show_y_guidelines

            count += 1

          end

        end

      end

      # Draws the X axis guidelines

      def draw_x_guidelines( label_height, count )

        if count != 0

          @graph.add_element( "path", {

            "d" => "M#{label_height*count} 0 v#@graph_height",

            "class" => "guideLines"

          })

        end

      end

      # Draws the Y axis guidelines

      def draw_y_guidelines( label_height, count )

        if count != 0

          @graph.add_element( "path", {

            "d" => "M0 #{@graph_height-(label_height*count)} h#@graph_width",

            "class" => "guideLines"

          })

        end

      end

      # Draws the graph title and subtitle

      def draw_titles

        if show_graph_title

          @root.add_element( "text", {

            "x" => (width / 2).to_s,

            "y" => (title_font_size).to_s,

            "class" => "mainTitle"

          }).text = graph_title.to_s

        end

        if show_graph_subtitle

          y_subtitle = show_graph_title ? 

            title_font_size + 10 :

            subtitle_font_size

          @root.add_element("text", {

            "x" => (width / 2).to_s,

            "y" => (y_subtitle).to_s,

            "class" => "subTitle"

          }).text = graph_subtitle.to_s

        end

        if show_x_title

          y = @graph_height + @border_top + x_title_font_size

          if show_x_labels

            y += x_label_font_size + 5 if stagger_x_labels

            y += x_label_font_size + 5

          end

          x = width / 2

          @root.add_element("text", {

            "x" => x.to_s,

            "y" => y.to_s,

            "class" => "xAxisTitle",

          }).text = x_title.to_s

        end

        if show_y_title

          x = y_title_font_size + (y_title_text_direction==:bt ? 3 : -3)

          y = height / 2

          text = @root.add_element("text", {

            "x" => x.to_s,

            "y" => y.to_s,

            "class" => "yAxisTitle",

          })

          text.text = y_title.to_s

          if y_title_text_direction == :bt

            text.attributes["transform"] = "rotate( -90, #{x}, #{y} )"

          else

            text.attributes["transform"] = "rotate( 90, #{x}, #{y} )"

          end

        end

      end

      def keys 

        return @data.collect{ |d| d[:title] }

      end

      # Draws the legend on the graph

      def draw_legend

        if key

          group = @root.add_element( "g" )

          key_count = 0

          for key_name in keys

            y_offset = (KEY_BOX_SIZE * key_count) + (key_count * 5)

            group.add_element( "rect", {

              "x" => 0.to_s,

              "y" => y_offset.to_s,

              "width" => KEY_BOX_SIZE.to_s,

              "height" => KEY_BOX_SIZE.to_s,

              "class" => "key#{key_count+1}"

            })

            group.add_element( "text", {

              "x" => (KEY_BOX_SIZE + 5).to_s,

              "y" => (y_offset + KEY_BOX_SIZE).to_s,

              "class" => "keyText"

            }).text = key_name.to_s

            key_count += 1

          end

          case key_position

          when :right

            x_offset = @graph_width + @border_left + 10

            y_offset = @border_top + 20

          when :bottom

            x_offset = @border_left + 20

            y_offset = @border_top + @graph_height + 5

            if show_x_labels

                          max_x_label_height_px = (not rotate_x_labels) ? 

                                x_label_font_size :

                                get_x_labels.max{|a,b| 

                                  a.to_s.length<=>b.to_s.length

                                }.to_s.length * x_label_font_size * 0.6

                x_label_font_size

              y_offset += max_x_label_height_px

              y_offset += max_x_label_height_px + 5 if stagger_x_labels

            end

            y_offset += x_title_font_size + 5 if show_x_title

          end

          group.attributes["transform"] = "translate(#{x_offset} #{y_offset})"

        end

      end

      private

      def sort_multiple( arrys, lo=0, hi=arrys[0].length-1 )

        if lo < hi

          p = partition(arrys,lo,hi)

          sort_multiple(arrys, lo, p-1)

          sort_multiple(arrys, p+1, hi)

        end

        arrys 

      end

      def partition( arrys, lo, hi )

        p = arrys[0][lo]

        l = lo

        z = lo+1

        while z <= hi

          if arrys[0][z] < p

            l += 1

            arrys.each { |arry| arry[z], arry[l] = arry[l], arry[z] }

          end

          z += 1

        end

        arrys.each { |arry| arry[lo], arry[l] = arry[l], arry[lo] }

        l

      end

      def style

        if no_css

          styles = parse_css

          @root.elements.each("//*[@class]") { |el|

            cl = el.attributes["class"]

            style = styles[cl]

            style += el.attributes["style"] if el.attributes["style"]

            el.attributes["style"] = style

          }

        end

      end

      def parse_css

        css = get_style

        rv = {}

        while css =~ /^(\.(\w+)(?:\s*,\s*\.\w+)*)\s*\{/m

          names_orig = names = $1

          css = $'

          css =~ /([^}]+)\}/m

          content = $1

          css = $'

          nms = []

          while names =~ /^\s*,?\s*\.(\w+)/

            nms << $1

            names = $'

          end

          content = content.tr( "\n\t", " ")

          for name in nms

            current = rv[name]

            current = current ? current+"; "+content : content

            rv[name] = current.strip.squeeze(" ")

          end

        end

        return rv

      end

      # Override and place code to add defs here

      def add_defs defs

      end

      def start_svg

        # Base document

        @doc = Document.new

        @doc << XMLDecl.new

        @doc << DocType.new( %q{svg PUBLIC "-//W3C//DTD SVG 1.0//EN" } +

          %q{"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd"} )

        if style_sheet && style_sheet != ''

          @doc << Instruction.new( "xml-stylesheet",

            %Q{href="#{style_sheet}" type="text/css"} )

        end

        @root = @doc.add_element( "svg", {

          "width" => width.to_s,

          "height" => height.to_s,

          "viewBox" => "0 0 #{width} #{height}",

          "xmlns" => "http://www.w3.org/2000/svg",

          "xmlns:xlink" => "http://www.w3.org/1999/xlink",

          "xmlns:a3" => "http://ns.adobe.com/AdobeSVGViewerExtensions/3.0/",

          "a3:scriptImplementation" => "Adobe"

        })

        @root << Comment.new( " "+"\\"*66 )

        @root << Comment.new( " Created with SVG::Graph " )

        @root << Comment.new( " SVG::Graph by Sean E. Russell " )

        @root << Comment.new( " Losely based on SVG::TT::Graph for Perl by"+

        " Leo Lapworth & Stephan Morgan " )

        @root << Comment.new( " "+"/"*66 )

        defs = @root.add_element( "defs" )

        add_defs defs

        if not(style_sheet && style_sheet != '') and !no_css

          @root << Comment.new(" include default stylesheet if none specified ")

          style = defs.add_element( "style", {"type"=>"text/css"} )

          style << CData.new( get_style )

        end

        @root << Comment.new( "SVG Background" )

        @root.add_element( "rect", {

          "width" => width.to_s,

          "height" => height.to_s,

          "x" => "0",

          "y" => "0",

          "class" => "svgBackground"

        })

      end

      def calculate_graph_dimensions

        calculate_left_margin

        calculate_right_margin

        calculate_bottom_margin

        calculate_top_margin

        @graph_width = width - @border_left - @border_right

        @graph_height = height - @border_top - @border_bottom

      end

      def get_style

        return <<EOL

/* Copy from here for external style sheet */

.svgBackground{

  fill:#ffffff;

}

.graphBackground{

  fill:#f0f0f0;

}

/* graphs titles */

.mainTitle{

  text-anchor: middle;

  fill: #000000;

  font-size: #{title_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.subTitle{

  text-anchor: middle;

  fill: #999999;

  font-size: #{subtitle_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.axis{

  stroke: #000000;

  stroke-width: 1px;

}

.guideLines{

  stroke: #666666;

  stroke-width: 1px;

  stroke-dasharray: 5 5;

}

.xAxisLabels{

  text-anchor: middle;

  fill: #000000;

  font-size: #{x_label_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.yAxisLabels{

  text-anchor: end;

  fill: #000000;

  font-size: #{y_label_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.xAxisTitle{

  text-anchor: middle;

  fill: #ff0000;

  font-size: #{x_title_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.yAxisTitle{

  fill: #ff0000;

  text-anchor: middle;

  font-size: #{y_title_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.dataPointLabel{

  fill: #000000;

  text-anchor:middle;

  font-size: 10px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

.staggerGuideLine{

  fill: none;

  stroke: #000000;

  stroke-width: 0.5px;  

}

#{get_css}

.keyText{

  fill: #000000;

  text-anchor:start;

  font-size: #{key_font_size}px;

  font-family: "Arial", sans-serif;

  font-weight: normal;

}

/* End copy for external style sheet */

EOL

      end

    end

  end

end