text: ###############################################################################
  #
  # ChartDoughnut - A class for writing the Excel XLSX Doughnut charts.
  #
  # Copyright 2013-2019, John McNamara, jmcnamara@cpan.org
  #
  
  from warnings import warn
  from . import chart_pie
  
  
  class ChartDoughnut(chart_pie.ChartPie):
      """
      A class for writing the Excel XLSX Doughnut charts.
  
  
      """
  
      ###########################################################################
      #
      # Public API.
      #
      ###########################################################################
  
      def __init__(self, options=None):
          """
          Constructor.
  
          """
          super(ChartDoughnut, self).__init__()
  
          if options is None:
              options = {}
  
          self.vary_data_color = 1
          self.rotation = 0
          self.hole_size = 50
  
      def set_hole_size(self, size):
          """
          Set the Doughnut chart hole size.
  
          Args:
              size: 10 <= size <= 90.
  
          Returns:
              Nothing.
  
          """
          if size is None:
              return
  
          # Ensure the size is in Excel's range.
          if size < 10 or size > 90:
              warn("Chart hole size %d outside Excel range: 10 <= size <= 90"
                   % size)
              return
  
          self.hole_size = int(size)
  
      ###########################################################################
      #
      # Private API.
      #
      ###########################################################################
  
      def _write_chart_type(self, args):
          # Override the virtual superclass method with a chart specific method.
          # Write the c:doughnutChart element.
          self._write_doughnut_chart(args)
  
      ###########################################################################
      #
      # XML methods.
      #
      ###########################################################################
  
      def _write_doughnut_chart(self, args):
          # Write the <c:doughnutChart> element.  Over-ridden method to remove
          # axis_id code since Doughnut charts don't require val and cat axes.
          self._xml_start_tag('c:doughnutChart')
  
          # Write the c:varyColors element.
          self._write_vary_colors()
  
          # Write the series elements.
          for data in self.series:
              self._write_ser(data)
  
          # Write the c:firstSliceAng element.
          self._write_first_slice_ang()
  
          # Write the c:holeSize element.
          self._write_c_hole_size()
  
          self._xml_end_tag('c:doughnutChart')
  
      def _write_c_hole_size(self):
          # Write the <c:holeSize> element.
          attributes = [('val', self.hole_size)]
  
          self._xml_empty_tag('c:holeSize', attributes)
  