Nested numbers formatting using asciidoc

nested.rb

class CustomPDFConverter < (Asciidoctor::Converter.for 'pdf')
  register_for 'pdf'

  def init_pdf doc
    @parents = []
    super
  end

  def convert_olist node
    add_dest_for_block node if node.id
    # TODO: move list_numeral resolve to a method
    case node.style
    when 'arabic'
      list_numeral = 1
    when 'decimal'
      list_numeral = '01'
    when 'loweralpha'
      list_numeral = 'a'
    when 'upperalpha'
      list_numeral = 'A'
    when 'lowerroman'
      list_numeral = RomanNumeral.new 'i'
    when 'upperroman'
      list_numeral = RomanNumeral.new 'I'
    when 'lowergreek'
      list_numeral = LowercaseGreekA
    when 'unstyled', 'unnumbered', 'no-bullet'
      list_numeral = nil
    when 'none'
      list_numeral = ''
    else
      list_numeral = 1
    end
    if list_numeral && list_numeral != '' &&
      (start = (node.attr 'start', nil, false) || ((node.option? 'reversed') ? node.items.size : nil))
      if (start = start.to_i) > 1
        (start - 1).times { list_numeral = list_numeral.next }
      elsif start < 1 && !(::String === list_numeral)
        (start - 1).abs.times { list_numeral = list_numeral.pred }
      end
    end
    @list_numerals << list_numeral
    convert_outline_list node
    @list_numerals.pop
  end

  def convert_outline_list node
    # TODO: check if we're within one line of the bottom of the page
    # and advance to the next page if so (similar to logic for section titles)
    layout_caption node.title, category: :outline_list if node.title?

    opts = {}
    if (align = resolve_alignment_from_role node.roles)
      opts[:align] = align
    elsif node.style == 'bibliography'
      opts[:align] = :left
    elsif (align = @theme.outline_list_text_align)
      # NOTE: theme setting only affects alignment of list text (not nested blocks)
      opts[:align] = align.to_sym
    end

    line_metrics = calc_line_metrics @theme.base_line_height
    complex = false
    # ...or if we want to give all items in the list the same treatment
    #complex = node.items.find(&:complex?) ? true : false
    if (node.context == :ulist && !@list_bullets[-1]) || (node.context == :olist && !@list_numerals[-1])
      if node.style == 'unstyled'
        # unstyled takes away all indentation
        list_indent = 0
      elsif (list_indent = @theme.outline_list_indent || 0) > 0
        # no-bullet aligns text with left-hand side of bullet position (as though there's no bullet)
        list_indent = [list_indent - (rendered_width_of_string %(#{node.context == :ulist ? ?\u2022 : '1.'}x)), 0].max
      end
    else
      list_indent = @theme.outline_list_indent || 0
    end
    indent list_indent do
      node.items.each do |item|
        allocate_space_for_list_item line_metrics
        convert_outline_list_item item, node, opts
      end
    end
    # NOTE: Children will provide the necessary bottom margin if last item is complex.
    # However, don't leave gap at the bottom if list is nested in an outline list
    unless complex || (node.nested? && node.parent.parent.outline?)
      # correct bottom margin of last item
      margin_bottom((@theme.prose_margin_bottom || 0) - (@theme.outline_list_item_spacing || 0))
    end
  end

  def convert_outline_list_item node, list, opts = {}
    # TODO: move this to a draw_bullet (or draw_marker) method
    marker_style = {}
    marker_style[:font_color] = @theme.outline_list_marker_font_color || @font_color
    marker_style[:font_family] = font_family
    marker_style[:font_size] = font_size
    marker_style[:line_height] = @theme.base_line_height
    case (list_type = list.context)
    when :ulist
      complex = node.complex?
      if (marker_type = @list_bullets[-1])
        if marker_type == :checkbox
          # QUESTION should we remove marker indent if not a checkbox?
          if node.attr? 'checkbox', nil, false
            marker_type = (node.attr? 'checked', nil, false) ? :checked : :unchecked
            marker = @theme[%(ulist_marker_#{marker_type}_content)] || BallotBox[marker_type]
          end
        else
          marker = @theme[%(ulist_marker_#{marker_type}_content)] || Bullets[marker_type]
        end
        [:font_color, :font_family, :font_size, :line_height].each do |prop|
          marker_style[prop] = @theme[%(ulist_marker_#{marker_type}_#{prop})] || @theme[%(ulist_marker_#{prop})] || marker_style[prop]
        end if marker
      end
    when :olist
      complex = node.complex?
      if (index = @list_numerals.pop)
        if index == ''
          marker = ''
        else
          marker = %(#{index}.)
          @parents << marker
          marker = @parents.join("")
          dir = (node.parent.option? 'reversed') ? :pred : :next
          @list_numerals << (index.public_send dir)
        end
      end
    when :dlist
      # NOTE: list.style is 'qanda'
      complex = node[1]&.complex?
      @list_numerals << (index = @list_numerals.pop).next
      marker = %(#{index}.)
    else
      complex = node.complex?
      logger.warn %(unknown list type #{list_type.inspect}) unless scratch?
      marker = @theme.ulist_marker_disc_content || Bullets[:disc]
    end

    if marker
      if marker_style[:font_family] == 'fa'
        logger.info 'deprecated fa icon set found in theme; use fas, far, or fab instead' unless scratch?
        marker_style[:font_family] = FontAwesomeIconSets.find { |candidate| (icon_font_data candidate).yaml[candidate].value? marker } || 'fas'
      end
      marker_gap = rendered_width_of_char 'x'
      font marker_style[:font_family], size: marker_style[:font_size] do
        marker_width = rendered_width_of_string marker
        # NOTE compensate if character_spacing is not applied to first character
        # see https://github.com/prawnpdf/prawn/commit/c61c5d48841910aa11b9e3d6f0e01b68ce435329
        character_spacing_correction = 0
        character_spacing(-0.5) do
          character_spacing_correction = 0.5 if (rendered_width_of_char 'x', character_spacing: -0.5) == marker_gap
        end
        marker_height = height_of_typeset_text marker, line_height: marker_style[:line_height], single_line: true
        start_position = -marker_width + -marker_gap + character_spacing_correction
        float do
          start_new_page if @media == 'prepress' && cursor < marker_height
          flow_bounding_box start_position, width: marker_width do
            layout_prose marker,
                         align: :right,
                         character_spacing: -0.5,
                         color: marker_style[:font_color],
                         inline_format: false,
                         line_height: marker_style[:line_height],
                         margin: 0,
                         normalize: false,
                         single_line: true
          end
        end
      end
    end

    if complex
      traverse_list_item node, list_type, (opts.merge normalize_line_height: true)
    else
      traverse_list_item node, list_type, (opts.merge margin_bottom: @theme.outline_list_item_spacing, normalize_line_height: true)
    end

    @parents.pop
  end
end