-
-require File.dirname(__FILE__) + '/base'
-require File.dirname(__FILE__) + '/bar_conversion'
-
-class Gruff::Bar < Gruff::Base
-
- def draw
- # Labels will be centered over the left of the bar if
- # there are more labels than columns. This is basically the same
- # as where it would be for a line graph.
- @center_labels_over_point = (@labels.keys.length > @column_count ? true : false)
-
- super
- return unless @has_data
-
- draw_bars
- end
-
-protected
-
- def draw_bars
- # Setup spacing.
- #
- # Columns sit side-by-side.
- spacing_factor = 0.9 # space between the bars
- @bar_width = @graph_width / (@column_count * @data.length).to_f
-
- @d = @d.stroke_opacity 0.0
-
- # Setup the BarConversion Object
- conversion = Gruff::BarConversion.new()
- conversion.graph_height = @graph_height
- conversion.graph_top = @graph_top
-
- # Set up the right mode [1,2,3] see BarConversion for further explanation
- if @minimum_value >= 0 then
- # all bars go from zero to positiv
- conversion.mode = 1
- else
- # all bars go from 0 to negativ
- if @maximum_value <= 0 then
- conversion.mode = 2
- else
- # bars either go from zero to negativ or to positiv
- conversion.mode = 3
- conversion.spread = @spread
- conversion.minimum_value = @minimum_value
- conversion.zero = -@minimum_value/@spread
- end
- end
-
- # iterate over all normalised data
- @norm_data.each_with_index do |data_row, row_index|
-
- data_row[1].each_with_index do |data_point, point_index|
- # Use incremented x and scaled y
- # x
- left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index)))
- right_x = left_x + @bar_width * spacing_factor
- # y
- conv = []
- conversion.getLeftYRightYscaled( data_point, conv )
-
- # create new bar
- @d = @d.fill data_row[DATA_COLOR_INDEX]
- @d = @d.rectangle(left_x, conv[0], right_x, conv[1])
-
- # Calculate center based on bar_width and current row
- label_center = @graph_left +
- (@data.length * @bar_width * point_index) +
- (@data.length * @bar_width / 2.0)
- # Subtract half a bar width to center left if requested
- draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)
- end
-
- end
-
- # Draw the last label if requested
- draw_label(@graph_right, @column_count) if @center_labels_over_point
-
- @d.draw(@base_image)
- end
-
-end