--- /dev/null
+
+require File.dirname(__FILE__) + '/base'
+require File.dirname(__FILE__) + '/bar_conversion'
+
+class Gruff::Bar < Gruff::Base
+
+ def draw
+ # Labels will be centered over the left of the bar if
+ # there are more labels than columns. This is basically the same
+ # as where it would be for a line graph.
+ @center_labels_over_point = (@labels.keys.length > @column_count ? true : false)
+
+ super
+ return unless @has_data
+
+ draw_bars
+ end
+
+protected
+
+ def draw_bars
+ # Setup spacing.
+ #
+ # Columns sit side-by-side.
+ spacing_factor = 0.9 # space between the bars
+ @bar_width = @graph_width / (@column_count * @data.length).to_f
+
+ @d = @d.stroke_opacity 0.0
+
+ # Setup the BarConversion Object
+ conversion = Gruff::BarConversion.new()
+ conversion.graph_height = @graph_height
+ conversion.graph_top = @graph_top
+
+ # Set up the right mode [1,2,3] see BarConversion for further explanation
+ if @minimum_value >= 0 then
+ # all bars go from zero to positiv
+ conversion.mode = 1
+ else
+ # all bars go from 0 to negativ
+ if @maximum_value <= 0 then
+ conversion.mode = 2
+ else
+ # bars either go from zero to negativ or to positiv
+ conversion.mode = 3
+ conversion.spread = @spread
+ conversion.minimum_value = @minimum_value
+ conversion.zero = -@minimum_value/@spread
+ end
+ end
+
+ # iterate over all normalised data
+ @norm_data.each_with_index do |data_row, row_index|
+
+ data_row[1].each_with_index do |data_point, point_index|
+ # Use incremented x and scaled y
+ # x
+ left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index)))
+ right_x = left_x + @bar_width * spacing_factor
+ # y
+ conv = []
+ conversion.getLeftYRightYscaled( data_point, conv )
+
+ # create new bar
+ @d = @d.fill data_row[DATA_COLOR_INDEX]
+ @d = @d.rectangle(left_x, conv[0], right_x, conv[1])
+
+ # Calculate center based on bar_width and current row
+ label_center = @graph_left +
+ (@data.length * @bar_width * point_index) +
+ (@data.length * @bar_width / 2.0)
+ # Subtract half a bar width to center left if requested
+ draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)
+ end
+
+ end
+
+ # Draw the last label if requested
+ draw_label(@graph_right, @column_count) if @center_labels_over_point
+
+ @d.draw(@base_image)
+ end
+
+end