Class: IRB::ReidlineInputMethod

->() {
  dialog.trap_key = nil
  alt_d = [
    [Reline::Key.new(nil, 0xE4, true)], # Normal Alt+d.
    [27, 100], # Normal Alt+d when convert-meta isn't used.
    [195, 164], # The "ä" that appears when Alt+d is pressed on xterm.
    [226, 136, 130] # The "∂" that appears when Alt+d in pressed on iTerm2.
  ]

  if just_cursor_moving and completion_journey_data.nil?
    return nil
  end
  cursor_pos_to_render, result, pointer, autocomplete_dialog = context.pop(4)
  return nil if result.nil? or pointer.nil? or pointer < 0
  name = result[pointer]
  name = IRB::InputCompletor.retrieve_completion_data(name, doc_namespace: true)

  options = {}
  options[:extra_doc_dirs] = IRB.conf[:EXTRA_DOC_DIRS] unless IRB.conf[:EXTRA_DOC_DIRS].empty?
  driver = RDoc::RI::Driver.new(options)

  if key.match?(dialog.name)
    begin
      driver.display_names([name])
    rescue RDoc::RI::Driver::NotFoundError
    end
  end

  begin
    name = driver.expand_name(name)
  rescue RDoc::RI::Driver::NotFoundError
    return nil
  rescue
    return nil # unknown error
  end
  doc = nil
  used_for_class = false
  if not name =~ /#|\./
    found, klasses, includes, extends = driver.classes_and_includes_and_extends_for(name)
    if not found.empty?
      doc = driver.class_document(name, found, klasses, includes, extends)
      used_for_class = true
    end
  end
  unless used_for_class
    doc = RDoc::Markup::Document.new
    begin
      driver.add_method(doc, name)
    rescue RDoc::RI::Driver::NotFoundError
      doc = nil
    rescue
      return nil # unknown error
    end
  end
  return nil if doc.nil?
  width = 40

  right_x = cursor_pos_to_render.x + autocomplete_dialog.width
  if right_x + width > screen_width
    right_width = screen_width - (right_x + 1)
    left_x = autocomplete_dialog.column - width
    left_x = 0 if left_x < 0
    left_width = width > autocomplete_dialog.column ? autocomplete_dialog.column : width
    if right_width.positive? and left_width.positive?
      if right_width >= left_width
        width = right_width
        x = right_x
      else
        width = left_width
        x = left_x
      end
    elsif right_width.positive? and left_width <= 0
      width = right_width
      x = right_x
    elsif right_width <= 0 and left_width.positive?
      width = left_width
      x = left_x
    else # Both are negative width.
      return nil
    end
  else
    x = right_x
  end
  formatter = RDoc::Markup::ToAnsi.new
  formatter.width = width
  dialog.trap_key = alt_d
  message = 'Press Alt+d to read the full document'
  contents = [message] + doc.accept(formatter).split("\n")

  y = cursor_pos_to_render.y
  DialogRenderInfo.new(pos: Reline::CursorPos.new(x, y), contents: contents, width: width, bg_color: '49')
}