class Gruff::SideBar

Graph with individual horizontal bars instead of vertical bars.

Public Instance Methods

draw() click to toggle source
# File lib/gruff/side_bar.rb, line 8
def draw
  @has_left_labels = true
  super

  return unless @has_data

  # Setup spacing.
  #
  @bar_spacing ||= 0.9

  @bars_width = @graph_height / @column_count.to_f
  @bar_width = @bars_width * @bar_spacing / @norm_data.size
  @d         = @d.stroke_opacity 0.0
  height     = Array.new(@column_count, 0)
  length     = Array.new(@column_count, @graph_left)
  padding    = (@bars_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])
      temp2      = @graph_left + @graph_width - height[point_index]
      difference = temp2 - temp1

      left_x     = length[point_index] - 1
      left_y     = @graph_top + (@bars_width * point_index) + (@bar_width * row_index) + padding
      right_x    = left_x + difference
      right_y    = left_y + @bar_width

      height[point_index] += (data_point * @graph_width)

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

      # Calculate center based on bar_width and current row
      label_center = @graph_top + (@bars_width * point_index + @bars_width / 2)
      draw_label(label_center, point_index)
    end

  end

  @d.draw(@base_image)
end

Protected Instance Methods

draw_label(y_offset, index) click to toggle source

Draw on the Y axis instead of the X

# File lib/gruff/side_bar.rb, line 99
def draw_label(y_offset, index)
  if !@labels[index].nil? && @labels_seen[index].nil?
    @d.fill             = @font_color
    @d.font             = @font if @font
    @d.stroke           = 'transparent'
    @d.font_weight      = NormalWeight
    @d.pointsize        = scale_fontsize(@marker_font_size)
    @d.gravity          = EastGravity
    @d                  = @d.annotate_scaled(@base_image,
                            1, 1,
                            -@graph_left + LABEL_MARGIN * 2.0, y_offset,
                            @labels[index], @scale)
    @labels_seen[index] = 1
  end
end
draw_line_markers() click to toggle source

Instead of base class version, draws vertical background lines and label

# File lib/gruff/side_bar.rb, line 59
def draw_line_markers

  return if @hide_line_markers

  @d = @d.stroke_antialias false

  # Draw horizontal line markers and annotate with numbers
  @d = @d.stroke(@marker_color)
  @d = @d.stroke_width 1
  number_of_lines = 5

  # TODO Round maximum marker value to a round number like 100, 0.1, 0.5, etc.
  increment = significant(@maximum_value.to_f / number_of_lines)
  (0..number_of_lines).each do |index|

    line_diff    = (@graph_right - @graph_left) / number_of_lines
    x            = @graph_right - (line_diff * index) - 1
    @d           = @d.line(x, @graph_bottom, x, @graph_top)
    diff         = index - number_of_lines
    marker_label = diff.abs * increment

    unless @hide_line_numbers
      @d.fill      = @font_color
      @d.font      = @font if @font
      @d.stroke    = 'transparent'
      @d.pointsize = scale_fontsize(@marker_font_size)
      @d.gravity   = CenterGravity
      # TODO Center text over line
      @d           = @d.annotate_scaled( @base_image,
                        0, 0, # Width of box to draw text in
                        x, @graph_bottom + (LABEL_MARGIN * 2.0), # Coordinates of text
                        marker_label.to_s, @scale)
    end # unless
    @d = @d.stroke_antialias true
  end
end