+
+require File.dirname(__FILE__) + '/base'
+
+class Gruff::StackedBar < Gruff::Base
+
+ # Draws a bar graph, but multiple sets are stacked on top of each other.
+ def draw
+ get_maximum_by_stack
+ super
+ return unless @has_data
+
+ # Setup spacing.
+ #
+ # Columns sit stacked.
+ spacing_factor = 0.9
+ @bar_width = @graph_width / @column_count.to_f
+
+ @d = @d.stroke_opacity 0.0
+
+ height = Array.new(@column_count, 0)
+
+ @norm_data.each_with_index do |data_row, row_index|
+ @d = @d.fill data_row[DATA_COLOR_INDEX]
+
+ data_row[1].each_with_index do |data_point, point_index|
+ # Use incremented x and scaled y
+ left_x = @graph_left + (@bar_width * point_index)
+ left_y = @graph_top + (@graph_height -
+ data_point * @graph_height -
+ height[point_index]) + 1
+ right_x = left_x + @bar_width * spacing_factor
+ right_y = @graph_top + @graph_height - height[point_index] - 1
+
+ # update the total height of the current stacked bar
+ height[point_index] += (data_point * @graph_height - 2)
+
+ @d = @d.rectangle(left_x, left_y, right_x, right_y)
+
+ # Calculate center based on bar_width and current row
+ label_center = @graph_left + (@bar_width * point_index) + (@bar_width * spacing_factor / 2.0)
+ draw_label(label_center, point_index)
+ end
+
+ end
+
+ @d.draw(@base_image)
+ end
+
+end