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

    # File lib/gruff/bar.rb, line 23
23:   def draw_bars
24:     # Setup spacing.
25:     #
26:     # Columns sit side-by-side.
27:     @bar_spacing ||= 0.9 # space between the bars
28:     @bar_width = @graph_width / (@column_count * @data.length).to_f
29:     padding = (@bar_width * (1 - @bar_spacing)) / 2
30: 
31:     @d = @d.stroke_opacity 0.0
32: 
33:     # Setup the BarConversion Object
34:     conversion = Gruff::BarConversion.new()
35:     conversion.graph_height = @graph_height
36:     conversion.graph_top = @graph_top
37: 
38:     # Set up the right mode [1,2,3] see BarConversion for further explanation
39:     if @minimum_value >= 0 then
40:       # all bars go from zero to positiv
41:       conversion.mode = 1
42:     else
43:       # all bars go from 0 to negativ
44:       if @maximum_value <= 0 then
45:         conversion.mode = 2
46:       else
47:         # bars either go from zero to negativ or to positiv
48:         conversion.mode = 3
49:         conversion.spread = @spread
50:         conversion.minimum_value = @minimum_value
51:         conversion.zero = -@minimum_value/@spread
52:       end
53:     end
54: 
55:     # iterate over all normalised data
56:     @norm_data.each_with_index do |data_row, row_index|
57: 
58:       data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|
59:         # Use incremented x and scaled y
60:         # x
61:         left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index))) + padding
62:         right_x = left_x + @bar_width * @bar_spacing
63:         # y
64:         conv = []
65:         conversion.getLeftYRightYscaled( data_point, conv )
66: 
67:         # create new bar
68:         @d = @d.fill data_row[DATA_COLOR_INDEX]
69:         @d = @d.rectangle(left_x, conv[0], right_x, conv[1])
70: 
71:         # Calculate center based on bar_width and current row
72:         label_center = @graph_left + 
73:                       (@data.length * @bar_width * point_index) + 
74:                       (@data.length * @bar_width / 2.0)
75:         # Subtract half a bar width to center left if requested
76:         draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)
77:       end
78: 
79:     end
80: 
81:     # Draw the last label if requested
82:     draw_label(@graph_right, @column_count) if @center_labels_over_point
83: 
84:     @d.draw(@base_image)
85:   end