projects.mako.cc - selectricity-live/blob - vendor/plugins/gruff/lib/gruff/side_stacked_bar.rb

   1 require File.dirname(__FILE__) + '/base'
   2 require File.dirname(__FILE__) + '/side_bar'
   3
   4 ##
   5 # New gruff graph type added to enable sideways stacking bar charts
   6 # (basically looks like a x/y flip of a standard stacking bar chart)
   7 #
   8 # alun.eyre@googlemail.com
   9
  10 class Gruff::SideStackedBar < Gruff::SideBar
  11
  12   def draw
  13     @has_left_labels = true
  14     get_maximum_by_stack
  15     super
  16
  17     return unless @has_data
  18
  19     # Setup spacing.
  20     #
  21     # Columns sit stacked.
  22     spacing_factor = 0.9
  23
  24     @bar_width = @graph_height / @column_count.to_f
  25     @d = @d.stroke_opacity 0.0
  26     height = Array.new(@column_count, 0)
  27     length = Array.new(@column_count, @graph_left)
  28
  29     @norm_data.each_with_index do |data_row, row_index|
  30       @d = @d.fill data_row[DATA_COLOR_INDEX]
  31
  32       data_row[1].each_with_index do |data_point, point_index|
  33
  34           ## using the original calcs from the stacked bar chart to get the difference between
  35           ## part of the bart chart we wish to stack.
  36           temp1 = @graph_left + (@graph_width -
  37                                     data_point * @graph_width -
  38                                     height[point_index]) + 1
  39           temp2 = @graph_left + @graph_width - height[point_index] - 1
  40           difference = temp2 - temp1
  41
  42           left_x = length[point_index] #+ 1
  43               left_y = @graph_top + (@bar_width * point_index)
  44           right_x = left_x + difference
  45               right_y = left_y + @bar_width * spacing_factor
  46           length[point_index] += difference
  47         height[point_index] += (data_point * @graph_width - 2)
  48
  49         @d = @d.rectangle(left_x, left_y, right_x, right_y)
  50
  51         # Calculate center based on bar_width and current row
  52         label_center = @graph_top + (@bar_width * point_index) + (@bar_width * spacing_factor / 2.0)
  53         draw_label(label_center, point_index)
  54       end
  55
  56     end
  57
  58     @d.draw(@base_image)
  59   end
  60
  61   protected
  62
  63   def larger_than_max?(data_point, index=0)
  64     max(data_point, index) > @maximum_value
  65   end
  66
  67   def max(data_point, index)
  68     @data.inject(0) {|sum, item| sum + item[1][index]}
  69   end
  70
  71 end