class RDoc::Markup::Formatter

def accept_document document
  document.parts.each do |item|
    item.accept self
  end
end

def add_tag(name, start, stop)
  attr = @attributes.bitmap_for name
  @attr_tags << InlineTag.new(attr, start, stop)
end

def annotate(tag)
  tag
end

def convert content
  @markup.convert content, self
end

def convert_flow(flow)
  res = []
  flow.each do |item|
    case item
    when String then
      res << convert_string(item)
    when RDoc::Markup::AttrChanger then
      off_tags res, item
      on_tags res, item
    when RDoc::Markup::Special then
      res << convert_special(item)
    else
      raise "Unknown flow element: #{item.inspect}"
    end
  end
  res.join
end

def convert_special special
  return special.text if in_tt?
  handled = false
  @attributes.each_name_of special.type do |name|
    method_name = "handle_special_#{name}"
    if respond_to? method_name then
      special.text = send method_name, special
      handled = true
    end
  end
  unless handled then
    special_name = @attributes.as_string special.type
    raise RDoc::Error, "Unhandled special #{special_name}: #{special}"
  end
  special.text
end

def convert_string string
  string
end

def ignore *node
end

def in_tt?
  @in_tt > 0
end

def initialize options, markup = nil
  @options = options
  @markup = markup || RDoc::Markup.new
  @am     = @markup.attribute_manager
  @am.add_special(/<br>/, :HARD_BREAK)
  @attributes = @am.attributes
  @attr_tags = []
  @in_tt = 0
  @tt_bit = @attributes.bitmap_for :TT
  @hard_break = ''
end

def off_tags res, item
  attr_mask = item.turn_off
  return if attr_mask.zero?
  @attr_tags.reverse_each do |tag|
    if attr_mask & tag.bit != 0 then
      @in_tt -= 1 if tt? tag
      res << annotate(tag.off)
    end
  end
end

def on_tags res, item
  attr_mask = item.turn_on
  return if attr_mask.zero?
  @attr_tags.each do |tag|
    if attr_mask & tag.bit != 0 then
      res << annotate(tag.on)
      @in_tt += 1 if tt? tag
    end
  end
end

def tt? tag
  tag.bit == @tt_bit
end