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

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