projects.mako.cc - selectricity/blob - lib/gruff-0.2.8/lib/gruff/side_stacked_bar.rb

   1 ##
   2 # New gruff graph type added to enable sideways stacking bar charts (basically looks like a x/y
   3 # flip of a standard stacking bar chart)
   4 #
   5 # alun.eyre@googlemail.com
   6 #
   7 require File.dirname(__FILE__) + '/base'
   8
   9 class Gruff::SideStackedBar < Gruff::Base
  10
  11     # instead of base class version, draws vertical background lines and label
  12     def draw_line_markers
  13
  14       return if @hide_line_markers
  15
  16       # Draw horizontal line markers and annotate with numbers
  17       @d = @d.stroke(@marker_color)
  18       @d = @d.stroke_width 1
  19       number_of_lines = 5
  20
  21       # TODO Round maximum marker value to a round number like 100, 0.1, 0.5, etc.
  22       increment = significant(@maximum_value.to_f / number_of_lines)
  23       (0..number_of_lines).each do |index|
  24
  25         line_diff = (@graph_right - @graph_left) / number_of_lines
  26         x = @graph_right - (line_diff * index) - 1
  27         @d = @d.line(x, @graph_bottom, x, @graph_top)
  28
  29         diff = index - number_of_lines
  30         marker_label = diff.abs * increment
  31
  32         @d.fill = @marker_color
  33         @d.font = @font if @font
  34         @d.stroke = 'transparent'
  35         @d.pointsize = scale_fontsize(@marker_font_size)
  36 #        @d.gravity = NorthGravity
  37         @d = @d.annotate_scaled( @base_image,
  38                           100, 20,
  39                           x - (@marker_font_size/1.5), @graph_bottom + 40,
  40                           marker_label.to_s, @scale)
  41
  42       end
  43     end
  44
  45     # instead of base class version, modified to enable us to draw on the Y axis instead of X
  46     def draw_label(y_offset, index)
  47       if !@labels[index].nil? && @labels_seen[index].nil?
  48         @d.fill = @marker_color
  49         @d.font = @font if @font
  50         @d.stroke = 'transparent'
  51         @d.font_weight = NormalWeight
  52         @d.pointsize = scale_fontsize(@marker_font_size)
  53         @d.gravity = CenterGravity
  54         @d = @d.annotate_scaled(@base_image,
  55                                 1, 1,
  56                                 @graph_left / 2, y_offset,
  57                                 @labels[index], @scale)
  58         @labels_seen[index] = 1
  59       end
  60     end
  61
  62     def draw
  63       @has_left_labels = true
  64       get_maximum_by_stack
  65       super
  66
  67       return unless @has_data
  68
  69       # Setup spacing.
  70       #
  71       # Columns sit stacked.
  72       spacing_factor = 0.9
  73
  74       @bar_width = @graph_height / @column_count.to_f
  75       @d = @d.stroke_opacity 0.0
  76       height = Array.new(@column_count, 0)
  77       length = Array.new(@column_count, @graph_left)
  78
  79       @norm_data.each_with_index do |data_row, row_index|
  80         @d = @d.fill data_row[DATA_COLOR_INDEX]
  81
  82         data_row[1].each_with_index do |data_point, point_index|
  83
  84           ## using the original calcs from the stacked bar chart to get the difference between
  85           ## part of the bart chart we wish to stack.
  86           temp1 = @graph_left + (@graph_width -
  87                                       data_point * @graph_width -
  88                                       height[point_index]) + 1
  89           temp2 = @graph_left + @graph_width - height[point_index] - 1
  90           difference = temp2 - temp1
  91
  92           left_x = length[point_index] #+ 1
  93                 left_y = @graph_top + (@bar_width * point_index)
  94           right_x = left_x + difference
  95                 right_y = left_y + @bar_width * spacing_factor
  96           length[point_index] += difference
  97           height[point_index] += (data_point * @graph_width - 2)
  98
  99           @d = @d.rectangle(left_x, left_y, right_x, right_y)
 100
 101           # Calculate center based on bar_width and current row
 102           label_center = @graph_top + (@bar_width * point_index) + (@bar_width * spacing_factor / 2.0)
 103           draw_label(label_center, point_index)
 104         end
 105
 106       end
 107
 108       @d.draw(@base_image)
 109     end
 110
 111     protected
 112
 113     def larger_than_max?(data_point, index=0)
 114       max(data_point, index) > @maximum_value
 115     end
 116
 117     def max(data_point, index)
 118       @data.inject(0) {|sum, item| sum + item[1][index]}
 119     end
 120
 121 end