Contents

require File.dirname(__FILE__) + '/base'
require File.dirname(__FILE__) + '/stacked_mixin'
require File.dirname(__FILE__) + '/ldata_mixin'

class Gruff::StackedBar < Gruff::Base
    include StackedMixin
    include LdataMixin

    # Draws a bar graph, but multiple sets are stacked on top of each other.
    def draw
      get_maximum_by_stack
      super
      draw_stacked_bars if @has_data
      draw_ldata if @has_ldata
    end


    def draw_stacked_bars

      # Setup spacing.
      #
      # Columns sit stacked.
      spacing_factor = 0.9
      @bar_width = @graph_width / @column_count.to_f
      padding = (@bar_width * (1 - spacing_factor)) / 2
    
      @d = @d.stroke_opacity 0.0
      
      height = Array.new(@column_count, 0)
    
      @norm_data.each_with_index do |data_row, row_index|      
        data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|
          @d = @d.fill data_row[DATA_COLOR_INDEX]
          
          # 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)

          # Use incremented x and scaled y
          left_x = @graph_left + (@bar_width * point_index) + padding
          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
          

	  if @has_ldata
	    @ldata_offset_and_increment[row_index] ||=
	      [ label_center, @bar_width ]
	  end

          next if (data_point == 0)
	  
	  # update the total height of the current stacked bar
          height[point_index] += (data_point * @graph_height ) 
          @d = @d.rectangle(left_x, left_y, right_x, right_y)
        end

      end
    
      @d.draw(@base_image)    
    end

end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
jslade-gruff-0.3.5	lib/gruff/stacked_bar.rb