# File lib/gruff/bar.rb, line 6
 6:   def draw
 7:     # Labels will be centered over the left of the bar if
 8:     # there are more labels than columns. This is basically the same 
 9:     # as where it would be for a line graph.
10:     @center_labels_over_point = (@labels.keys.length > @column_count ? true : false)
11:     
12:     super
13:     return unless @has_data
14: 
15:     draw_bars
16:   end

    # File lib/gruff/bar.rb, line 20
20:   def draw_bars
21:     # Setup spacing.
22:     #
23:     # Columns sit side-by-side.
24:     spacing_factor = 0.9 # space between the bars
25:     @bar_width = @graph_width / (@column_count * @data.length).to_f
26: 
27:     @d = @d.stroke_opacity 0.0
28: 
29:     # Setup the BarConversion Object
30:     conversion = Gruff::BarConversion.new()
31:     conversion.graph_height = @graph_height
32:     conversion.graph_top = @graph_top
33: 
34:     # Set up the right mode [1,2,3] see BarConversion for further explanation
35:     if @minimum_value >= 0 then
36:       # all bars go from zero to positiv
37:       conversion.mode = 1
38:     else
39:       # all bars go from 0 to negativ
40:       if @maximum_value <= 0 then
41:         conversion.mode = 2
42:       else
43:         # bars either go from zero to negativ or to positiv
44:         conversion.mode = 3
45:         conversion.spread = @spread
46:         conversion.minimum_value = @minimum_value
47:         conversion.zero = -@minimum_value/@spread
48:       end
49:     end
50: 
51:     # iterate over all normalised data
52:     @norm_data.each_with_index do |data_row, row_index|
53: 
54:       data_row[1].each_with_index do |data_point, point_index|
55:         # Use incremented x and scaled y
56:         # x
57:         left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index)))
58:         right_x = left_x + @bar_width * spacing_factor
59:         # y
60:         conv = []
61:         conversion.getLeftYRightYscaled( data_point, conv )
62: 
63:         # create new bar
64:         @d = @d.fill data_row[DATA_COLOR_INDEX]
65:         @d = @d.rectangle(left_x, conv[0], right_x, conv[1])
66: 
67:         # Calculate center based on bar_width and current row
68:         label_center = @graph_left + 
69:                       (@data.length * @bar_width * point_index) + 
70:                       (@data.length * @bar_width / 2.0)
71:         # Subtract half a bar width to center left if requested
72:         draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)
73:       end
74: 
75:     end
76: 
77:     # Draw the last label if requested
78:     draw_label(@graph_right, @column_count) if @center_labels_over_point
79: 
80:     @d.draw(@base_image)
81:   end