Class Gruff::SideStackedBar
In: lib/gruff/side_stacked_bar.rb
Parent: Gruff::SideBar

New gruff graph type added to enable sideways stacking bar charts (basically looks like a x/y flip of a standard stacking bar chart)

alun.eyre@googlemail.com

Methods

draw   larger_than_max?   max  

Included Modules

StackedMixin

Public Instance methods

[Source]

# File lib/gruff/side_stacked_bar.rb, line 14
  def draw
    @has_left_labels = true
    get_maximum_by_stack
    super

    return unless @has_data

    # Setup spacing.
    #
    # Columns sit stacked.
    @bar_spacing ||= 0.9

    @bar_width = @graph_height / @column_count.to_f
    @d = @d.stroke_opacity 0.0
    height = Array.new(@column_count, 0)
    length = Array.new(@column_count, @graph_left)
    padding = (@bar_width * (1 - @bar_spacing)) / 2

    @norm_data.each_with_index do |data_row, row_index|
      @d = @d.fill data_row[DATA_COLOR_INDEX]

      data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|

          ## using the original calcs from the stacked bar chart to get the difference between
          ## part of the bart chart we wish to stack.
          temp1 = @graph_left + (@graph_width -
                                    data_point * @graph_width - 
                                    height[point_index]) + 1
          temp2 = @graph_left + @graph_width - height[point_index] - 1
          difference = temp2 - temp1

          left_x = length[point_index] #+ 1
              left_y = @graph_top + (@bar_width * point_index) + padding
          right_x = left_x + difference
              right_y = left_y + @bar_width * @bar_spacing
          length[point_index] += difference
        height[point_index] += (data_point * @graph_width - 2)

        @d = @d.rectangle(left_x, left_y, right_x, right_y)

        # Calculate center based on bar_width and current row
        label_center = @graph_top + (@bar_width * point_index) + (@bar_width * @bar_spacing / 2.0)
        draw_label(label_center, point_index)
      end

    end

    @d.draw(@base_image)    
  end

Protected Instance methods

[Source]

# File lib/gruff/side_stacked_bar.rb, line 66
  def larger_than_max?(data_point, index=0)
    max(data_point, index) > @maximum_value
  end

[Source]

# File lib/gruff/side_stacked_bar.rb, line 70
  def max(data_point, index)
    @data.inject(0) {|sum, item| sum + item[DATA_VALUES_INDEX][index]}
  end

[Validate]