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require 'SVG/Graph/Graph'

module SVG

  module Graph

    # === Create presentation quality SVG line graphs easily

    # 

    # = Synopsis

    # 

    #   require 'SVG/Graph/Line'

    # 

    #   fields = %w(Jan Feb Mar);

    #   data_sales_02 = [12, 45, 21]

    #   data_sales_03 = [15, 30, 40]

    #   

    #   graph = SVG::Graph::Line.new({

    #           :height => 500,

    #            :width => 300,

    #           :fields => fields,

    #   })

    #   

    #   graph.add_data({

    #           :data => data_sales_02,

    #           :title => 'Sales 2002',

    #   })

    # 

    #   graph.add_data({

    #           :data => data_sales_03,

    #           :title => 'Sales 2003',

    #   })

    #   

    #   print "Content-type: image/svg+xml\r\n\r\n";

    #   print graph.burn();

    # 

    # = Description

    # 

    # This object aims to allow you to easily create high quality

    # SVG line graphs. You can either use the default style sheet

    # or supply your own. Either way there are many options which can

    # be configured to give you control over how the graph is

    # generated - with or without a key, data elements at each point,

    # title, subtitle etc.

    # 

    # = Examples

    # 

    # http://www.germane-software/repositories/public/SVG/test/single.rb

    # 

    # = Notes

    # 

    # The default stylesheet handles upto 10 data sets, if you

    # use more you must create your own stylesheet and add the

    # additional settings for the extra data sets. You will know

    # if you go over 10 data sets as they will have no style and

    # be in black.

    # 

    # = See also

    # 

    # * SVG::Graph::Graph

    # * SVG::Graph::BarHorizontal

    # * SVG::Graph::Bar

    # * 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 Line < SVG::Graph::Graph

      #    Show a small circle on the graph where the line

      #    goes from one point to the next.

      attr_accessor :show_data_points

      #    Accumulates each data set. (i.e. Each point increased by sum of 

      #   all previous series at same point). Default is 0, set to '1' to show.

      attr_accessor :stacked

      # Fill in the area under the plot if true

      attr_accessor :area_fill

      # The constructor takes a hash reference, fields (the names for each

      # field on the X axis) MUST be set, all other values are defaulted to 

      # those shown above - with the exception of style_sheet which defaults

      # to using the internal style sheet.

      def initialize config

        raise "fields was not supplied or is empty" unless config[:fields] &&

        config[:fields].kind_of?(Array) &&

        config[:fields].length > 0

                                super

                        end

      # In addition to the defaults set in Graph::initialize, sets

      # [show_data_points] true

      # [show_data_values] true

      # [stacked] false

      # [area_fill] false

                        def set_defaults

        init_with(

          :show_data_points   => true,

          :show_data_values   => true,

          :stacked            => false,

          :area_fill          => false

        )

        self.top_align = self.top_font = self.right_align = self.right_font = 1

      end

      protected

      def max_value

        max = 0

        if (stacked == true) then

          sums = Array.new(@config[:fields].length).fill(0)

          @data.each do |data|

            sums.each_index do |i|

              sums[i] += data[:data][i].to_f

            end

          end

          max = sums.max

        else

          max = @data.collect{|x| x[:data].max}.max

        end

        return max

      end

      def min_value

        min = 0

        if (min_scale_value.nil? == false) then

          min = min_scale_value

        elsif (stacked == true) then

          min = @data[-1][:data].min

        else

          min = @data.collect{|x| x[:data].min}.min

        end

        return min

      end

      def get_x_labels

        @config[:fields]

      end

      def calculate_left_margin

        super

        label_left = @config[:fields][0].length / 2 * font_size * 0.6

        @border_left = label_left if label_left > @border_left

      end

      def get_y_labels

        maxvalue = max_value

        minvalue = min_value

        range = maxvalue - minvalue

        top_pad = range == 0 ? 10 : range / 20.0

        scale_range = (maxvalue + top_pad) - minvalue

        scale_division = scale_divisions || (scale_range / 10.0)

        if scale_integers

          scale_division = scale_division < 1 ? 1 : scale_division.round

        end

        rv = []

        maxvalue = maxvalue%scale_division == 0 ? 

          maxvalue : maxvalue + scale_division

        minvalue.step( maxvalue, scale_division ) {|v| rv << v}

        return rv

      end

      def calc_coords(field, value, width = field_width, height = field_height)

        coords = {:x => 0, :y => 0}

        coords[:x] = width * field

        coords[:y] = @graph_height - value * height

        return coords

      end

      def draw_data

        minvalue = min_value

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

                         (get_y_labels.max - get_y_labels.min)

        fieldwidth = field_width

        line = @data.length

        prev_sum = Array.new(@config[:fields].length).fill(0)

        cum_sum = Array.new(@config[:fields].length).fill(-minvalue)

        for data in @data.reverse

          lpath = ""

          apath = ""

          if not stacked then cum_sum.fill(-minvalue) end

          data[:data].each_index do |i|

            cum_sum[i] += data[:data][i]

            c = calc_coords(i, cum_sum[i], fieldwidth, fieldheight)

            lpath << "#{c[:x]} #{c[:y]} "

          end

          if area_fill

            if stacked then

              (prev_sum.length - 1).downto 0 do |i|

                c = calc_coords(i, prev_sum[i], fieldwidth, fieldheight)

                apath << "#{c[:x]} #{c[:y]} "

              end

              c = calc_coords(0, prev_sum[0], fieldwidth, fieldheight)

            else

              apath = "V#@graph_height"

              c = calc_coords(0, 0, fieldwidth, fieldheight)

            end

            @graph.add_element("path", {

              "d" => "M#{c[:x]} #{c[:y]} L" + lpath + apath + "Z",

              "class" => "fill#{line}"

            })

          end

          @graph.add_element("path", {

            "d" => "M0 #@graph_height L" + lpath,

            "class" => "line#{line}"

          })

          if show_data_points || show_data_values

            cum_sum.each_index do |i|

              if show_data_points

                @graph.add_element( "circle", {

                  "cx" => (fieldwidth * i).to_s,

                  "cy" => (@graph_height - cum_sum[i] * fieldheight).to_s,

                  "r" => "2.5",

                  "class" => "dataPoint#{line}"

                })

              end

              make_datapoint_text( 

                fieldwidth * i, 

                @graph_height - cum_sum[i] * fieldheight - 6,

                cum_sum[i] + minvalue

              )

            end

          end

          prev_sum = cum_sum.dup

          line -= 1

        end

      end

      def get_css

        return <<EOL

/* default line styles */

.line1{

        fill: none;

        stroke: #ff0000;

        stroke-width: 1px;        

}

.line2{

        fill: none;

        stroke: #0000ff;

        stroke-width: 1px;        

}

.line3{

        fill: none;

        stroke: #00ff00;

        stroke-width: 1px;        

}

.line4{

        fill: none;

        stroke: #ffcc00;

        stroke-width: 1px;        

}

.line5{

        fill: none;

        stroke: #00ccff;

        stroke-width: 1px;        

}

.line6{

        fill: none;

        stroke: #ff00ff;

        stroke-width: 1px;        

}

.line7{

        fill: none;

        stroke: #00ffff;

        stroke-width: 1px;        

}

.line8{

        fill: none;

        stroke: #ffff00;

        stroke-width: 1px;        

}

.line9{

        fill: none;

        stroke: #ccc6666;

        stroke-width: 1px;        

}

.line10{

        fill: none;

        stroke: #663399;

        stroke-width: 1px;        

}

.line11{

        fill: none;

        stroke: #339900;

        stroke-width: 1px;        

}

.line12{

        fill: none;

        stroke: #9966FF;

        stroke-width: 1px;        

}

/* default fill styles */

.fill1{

        fill: #cc0000;

        fill-opacity: 0.2;

        stroke: none;

}

.fill2{

        fill: #0000cc;

        fill-opacity: 0.2;

        stroke: none;

}

.fill3{

        fill: #00cc00;

        fill-opacity: 0.2;

        stroke: none;

}

.fill4{

        fill: #ffcc00;

        fill-opacity: 0.2;

        stroke: none;

}

.fill5{

        fill: #00ccff;

        fill-opacity: 0.2;

        stroke: none;

}

.fill6{

        fill: #ff00ff;

        fill-opacity: 0.2;

        stroke: none;

}

.fill7{

        fill: #00ffff;

        fill-opacity: 0.2;

        stroke: none;

}

.fill8{

        fill: #ffff00;

        fill-opacity: 0.2;

        stroke: none;

}

.fill9{

        fill: #cc6666;

        fill-opacity: 0.2;

        stroke: none;

}

.fill10{

        fill: #663399;

        fill-opacity: 0.2;

        stroke: none;

}

.fill11{

        fill: #339900;

        fill-opacity: 0.2;

        stroke: none;

}

.fill12{

        fill: #9966FF;

        fill-opacity: 0.2;

        stroke: none;

}

/* default line styles */

.key1,.dataPoint1{

        fill: #ff0000;

        stroke: none;

        stroke-width: 1px;        

}

.key2,.dataPoint2{

        fill: #0000ff;

        stroke: none;

        stroke-width: 1px;        

}

.key3,.dataPoint3{

        fill: #00ff00;

        stroke: none;

        stroke-width: 1px;        

}

.key4,.dataPoint4{

        fill: #ffcc00;

        stroke: none;

        stroke-width: 1px;        

}

.key5,.dataPoint5{

        fill: #00ccff;

        stroke: none;

        stroke-width: 1px;        

}

.key6,.dataPoint6{

        fill: #ff00ff;

        stroke: none;

        stroke-width: 1px;        

}

.key7,.dataPoint7{

        fill: #00ffff;

        stroke: none;

        stroke-width: 1px;        

}

.key8,.dataPoint8{

        fill: #ffff00;

        stroke: none;

        stroke-width: 1px;        

}

.key9,.dataPoint9{

        fill: #cc6666;

        stroke: none;

        stroke-width: 1px;        

}

.key10,.dataPoint10{

        fill: #663399;

        stroke: none;

        stroke-width: 1px;        

}

.key11,.dataPoint11{

        fill: #339900;

        stroke: none;

        stroke-width: 1px;        

}

.key12,.dataPoint12{

        fill: #9966FF;

        stroke: none;

        stroke-width: 1px;        

}

EOL

      end

    end

  end

end