# -*- coding: utf-8 -*-
require 'write_xlsx/utility'

module Writexlsx
  # ==CELL FORMATTING
  #
  # This section describes the methods and properties that are available
  # for formatting cells in Excel. The properties of a cell that can be
  # formatted include: fonts, colours, patterns, borders, alignment and
  # number formatting.
  #
  # ===Creating and using a Format object
  #
  # Cell formatting is defined through a Format object. Format objects
  # are created by calling the workbook add_format() method as follows:
  #
  #     format1 = workbook.add_format             # Set properties later
  #     format2 = workbook.add_format(props_hash) # Set at creation
  #
  # The format object holds all the formatting properties that can be applied
  # to a cell, a row or a column. The process of setting these properties is
  # discussed in the next section.
  #
  # Once a Format object has been constructed and its properties have been
  # set it can be passed as an argument to the worksheet write methods as
  # follows:
  #
  #     worksheet.write( 0, 0, 'One', format )
  #     worksheet.write_string( 1, 0, 'Two', format )
  #     worksheet.write_number( 2, 0, 3, format )
  #     worksheet.write_blank( 3, 0, format )
  #
  # Formats can also be passed to the worksheet set_row() and set_column()
  # methods to define the default property for a row or column.
  #
  #     worksheet.set_row( 0, 15, format )
  #     worksheet.set_column( 0, 0, 15, format )
  #
  # ===Format methods and Format properties
  #
  # The following table shows the Excel format categories, the formatting
  # properties that can be applied and the equivalent object method:
  #
  #     Category   Description       Property        Method Name
  #     --------   -----------       --------        -----------
  #     Font       Font type         font            set_font()
  #                Font size         size            set_size()
  #                Font color        color           set_color()
  #                Bold              bold            set_bold()
  #                Italic            italic          set_italic()
  #                Underline         underline       set_underline()
  #                Strikeout         font_strikeout  set_font_strikeout()
  #                Super/Subscript   font_script     set_font_script()
  #                Outline           font_outline    set_font_outline()
  #                Shadow            font_shadow     set_font_shadow()
  #
  #     Number     Numeric format    num_format      set_num_format()
  #
  #     Protection Lock cells        locked          set_locked()
  #                Hide formulas     hidden          set_hidden()
  #
  #     Alignment  Horizontal align  align           set_align()
  #                Vertical align    valign          set_align()
  #                Rotation          rotation        set_rotation()
  #                Text wrap         text_wrap       set_text_wrap()
  #                Justify last      text_justlast   set_text_justlast()
  #                Center across     center_across   set_center_across()
  #                Indentation       indent          set_indent()
  #                Shrink to fit     shrink          set_shrink()
  #
  #     Pattern    Cell pattern      pattern         set_pattern()
  #                Background color  bg_color        set_bg_color()
  #                Foreground color  fg_color        set_fg_color()
  #
  #     Border     Cell border       border          set_border()
  #                Bottom border     bottom          set_bottom()
  #                Top border        top             set_top()
  #                Left border       left            set_left()
  #                Right border      right           set_right()
  #                Border color      border_color    set_border_color()
  #                Bottom color      bottom_color    set_bottom_color()
  #                Top color         top_color       set_top_color()
  #                Left color        left_color      set_left_color()
  #                Right color       right_color     set_right_color()
  #
  # There are two ways of setting Format properties: by using the object
  # method interface or by setting the property directly. For example,
  # a typical use of the method interface would be as follows:
  #
  #     format = workbook.add_format
  #     format.set_bold
  #     format.set_color( 'red' )
  #
  # By comparison the properties can be set directly by passing a hash
  # of properties to the Format constructor:
  #
  #     format = workbook.add_format( :bold => 1, :color => 'red' )
  #
  # or after the Format has been constructed by means of the
  # set_format_properties() method as follows:
  #
  #     format = workbook.add_format
  #     format.set_format_properties( :bold => 1, :color => 'red' )
  #
  # You can also store the properties in one or more named hashes and pass
  # them to the required method:
  #
  #     font = {
  #         :font  => 'Arial',
  #         :size  => 12,
  #         :color => 'blue',
  #         :bold  => 1
  #     }
  #
  #     shading = {
  #         :bg_color => 'green',
  #         :pattern  => 1
  #     }
  #
  #     format1 = workbook.add_format( font )           # Font only
  #     format2 = workbook.add_format( font, shading )  # Font and shading
  #
  # The provision of two ways of setting properties might lead you to wonder
  # which is the best way. The method mechanism may be better is you prefer
  # setting properties via method calls (which the author did when the code
  # was first written) otherwise passing properties to the constructor has
  # proved to be a little more flexible and self documenting in practice.
  # An additional advantage of working with property hashes is that it allows
  # you to share formatting between workbook objects as shown in the example
  # above.
  #
  # ===Working with formats
  #
  # The default format is Arial 10 with all other properties off.
  #
  # Each unique format in WriteXLSX must have a corresponding Format
  # object. It isn't possible to use a Format with a write() method and then
  # redefine the Format for use at a later stage. This is because a Format
  # is applied to a cell not in its current state but in its final state.
  # Consider the following example:
  #
  #     format = workbook.add_format
  #     format.set_bold
  #     format.set_color( 'red' )
  #     worksheet.write( 'A1', 'Cell A1', format )
  #     format.set_color( 'green' )
  #     worksheet.write( 'B1', 'Cell B1', format )
  #
  # Cell A1 is assigned the Format format which is initially set to the colour
  # red. However, the colour is subsequently set to green. When Excel displays
  # Cell A1 it will display the final state of the Format which in this case
  # will be the colour green.
  #
  # In general a method call without an argument will turn a property on,
  # for example:
  #
  #     format1 = workbook.add_format
  #     format1.set_bold         # Turns bold on
  #     format1.set_bold( 1 )    # Also turns bold on
  #     format1.set_bold( 0 )    # Turns bold off
  #
  class Format
    include Writexlsx::Utility

    attr_reader :xf_index, :dxf_index, :num_format   # :nodoc:
    attr_reader :underline, :font_script, :size, :theme, :font, :font_family, :hyperlink, :xf_id   # :nodoc:
    attr_reader :diag_type, :diag_color, :font_only, :color, :color_indexed   # :nodoc:
    attr_reader :left, :left_color, :right, :right_color, :top, :top_color, :bottom, :bottom_color   # :nodoc:
    attr_reader :font_scheme   # :nodoc:
    attr_accessor :num_format_index, :border_index, :font_index   # :nodoc:
    attr_accessor :fill_index, :font_condense, :font_extend, :diag_border   # :nodoc:
    attr_accessor :bg_color, :fg_color, :pattern   # :nodoc:

    attr_accessor :dxf_bg_color, :dxf_fg_color   # :nodoc:
    attr_reader :rotation, :bold, :italic, :font_strikeout

    def initialize(formats, params = {})   # :nodoc:
      @formats = formats

      @xf_index       = nil
      @dxf_index      = nil

      @num_format     = 'General'
      @num_format_index = 0
      @font_index     = 0
      @font           = 'Calibri'
      @size           = 11
      @bold           = 0
      @italic         = 0
      @color          = 0x0
      @underline      = 0
      @font_strikeout = 0
      @font_outline   = 0
      @font_shadow    = 0
      @font_script    = 0
      @font_family    = 2
      @font_charset   = 0
      @font_scheme    = 'minor'
      @font_condense  = 0
      @font_extend    = 0
      @theme          = 0
      @hyperlink      = 0
      @xf_id          = 0

      @hidden         = 0
      @locked         = 1

      @text_h_align   = 0
      @text_wrap      = 0
      @text_v_align   = 0
      @text_justlast  = 0
      @rotation       = 0

      @fg_color       = 0x00
      @bg_color       = 0x00
      @pattern        = 0
      @fill_index     = 0
      @fill_count     = 0

      @border_index   = 0
      @border_count   = 0

      @bottom         = 0
      @bottom_color   = 0x0
      @diag_border    = 0
      @diag_color     = 0x0
      @diag_type      = 0
      @left           = 0
      @left_color     = 0x0
      @right          = 0
      @right_color    = 0x0
      @top            = 0
      @top_color      = 0x0

      @indent         = 0
      @shrink         = 0
      @merge_range    = 0
      @reading_order  = 0
      @just_distrib   = 0
      @color_indexed  = 0
      @font_only      = 0

      set_format_properties(params) unless params.empty?
    end

    #
    # Copy the attributes of another Format object.
    #
    def copy(other)
      reserve = [
                 :xf_index,
                 :dxf_index,
                 :xdf_format_indices,
                 :palette
                ]
      (instance_variables - reserve).each do |v|
        instance_variable_set(v, other.instance_variable_get(v))
      end
    end

    #
    # :call-seq:
    #    set_format_properties( :bold => 1 [, :color => 'red'..] )
    #    set_format_properties( font [, shade, ..])
    #    set_format_properties( :bold => 1, font, ...)
    #      *) font  = { :color => 'red', :bold => 1 }
    #         shade = { :bg_color => 'green', :pattern => 1 }
    #
    # Convert hashes of properties to method calls.
    #
    # The properties of an existing Format object can be also be set by means
    # of set_format_properties():
    #
    #     format = workbook.add_format
    #     format.set_format_properties(:bold => 1, :color => 'red');
    #
    # However, this method is here mainly for legacy reasons. It is preferable
    # to set the properties in the format constructor:
    #
    #     format = workbook.add_format(:bold => 1, :color => 'red');
    #
    def set_format_properties(*properties)   # :nodoc:
      return if properties.empty?
      properties.each do |property|
        property.each do |key, value|
          # Strip leading "-" from Tk style properties e.g. "-color" => 'red'.
          key = key.sub(/^-/, '') if key.respond_to?(:to_str)

          # Create a sub to set the property.
          if value.respond_to?(:to_str) || !value.respond_to?(:+)
            send("set_#{key}", value.to_s)
          else
            send("set_#{key}", value)
          end
        end
      end
    end

    #
    # Return properties for an Style xf <alignment> sub-element.
    #
    def get_align_properties
      align = []    # Attributes to return

      # Check if any alignment options in the format have been changed.
      if @text_h_align != 0 || @text_v_align != 0 || @indent != 0 ||
         @rotation != 0 || @text_wrap != 0 || @shrink != 0 || @reading_order != 0
        changed = 1
      else
        return
      end

      # Indent is only allowed for horizontal left, right and distributed. If it
      # is defined for any other alignment or no alignment has been set then
      # default to left alignment.
      @text_h_align = 1 if @indent != 0 && ![1, 3, 7].include?(@text_h_align)

      # Check for properties that are mutually exclusive.
      @shrink       = 0 if @text_wrap != 0
      @shrink       = 0 if @text_h_align == 4    # Fill
      @shrink       = 0 if @text_h_align == 5    # Justify
      @shrink       = 0 if @text_h_align == 7    # Distributed
      @just_distrib = 0 if @text_h_align != 7    # Distributed
      @just_distrib = 0 if @indent != 0

      continuous = 'centerContinuous'

      align << ['horizontal', 'left']        if @text_h_align == 1
      align << ['horizontal', 'center']      if @text_h_align == 2
      align << ['horizontal', 'right']       if @text_h_align == 3
      align << ['horizontal', 'fill']        if @text_h_align == 4
      align << ['horizontal', 'justify']     if @text_h_align == 5
      align << ['horizontal', continuous]    if @text_h_align == 6
      align << ['horizontal', 'distributed'] if @text_h_align == 7

      align << ['justifyLastLine', 1] if @just_distrib != 0

      # Property 'vertical' => 'bottom' is a default. It sets applyAlignment
      # without an alignment sub-element.
      align << ['vertical', 'top']         if @text_v_align == 1
      align << ['vertical', 'center']      if @text_v_align == 2
      align << ['vertical', 'justify']     if @text_v_align == 4
      align << ['vertical', 'distributed'] if @text_v_align == 5

      align << ['indent',       @indent]   if @indent   != 0
      align << ['textRotation', @rotation] if @rotation != 0

      align << ['wrapText',     1] if @text_wrap != 0
      align << ['shrinkToFit',  1] if @shrink    != 0

      align << ['readingOrder', 1] if @reading_order == 1
      align << ['readingOrder', 2] if @reading_order == 2

      return changed, align
    end

    #
    # Return properties for an Excel XML <Protection> element.
    #
    def get_protection_properties
      attributes = []

      attributes << ['locked', 0] unless ptrue?(@locked)
      attributes << ['hidden', 1] if     ptrue?(@hidden)

      attributes.empty? ? nil : attributes
    end

    def set_bold(bold = 1)
      @bold = ptrue?(bold) ? 1 : 0
    end

    def inspect
      to_s
    end

    #
    # Returns a unique hash key for the Format object.
    #
    def get_format_key
      [get_font_key, get_border_key, get_fill_key, get_alignment_key, @num_format, @locked, @hidden].join(':')
    end

    #
    # Returns a unique hash key for a font. Used by Workbook.
    #
    def get_font_key
      [
        @bold,
        @color,
        @font_charset,
        @font_family,
        @font_outline,
        @font_script,
        @font_shadow,
        @font_strikeout,
        @font,
        @italic,
        @size,
        @underline,
        @theme
      ].join(':')
    end

    #
    # Returns a unique hash key for a border style. Used by Workbook.
    #
    def get_border_key
      [
        @bottom,
        @bottom_color,
        @diag_border,
        @diag_color,
        @diag_type,
        @left,
        @left_color,
        @right,
        @right_color,
        @top,
        @top_color
      ].join(':')
    end

    #
    # Returns a unique hash key for a fill style. Used by Workbook.
    #
    def get_fill_key
      [
        @pattern,
        @bg_color,
        @fg_color
      ].join(':')
    end

    #
    # Returns a unique hash key for alignment formats.
    #
    def get_alignment_key
      [@text_h_align, @text_v_align, @indent, @rotation, @text_wrap, @shrink, @reading_order].join(':')
    end

    #
    # Returns the index used by Worksheet->_XF()
    #
    def get_xf_index
      if @xf_index
        @xf_index
      elsif @formats.xf_index_by_key(get_format_key)
        @formats.xf_index_by_key(get_format_key)
      else
        @xf_index = @formats.set_xf_index_by_key(get_format_key)
      end
    end

    #
    # Returns the index used by Worksheet->_XF()
    #
    def get_dxf_index
      if @dxf_index
        @dxf_index
      elsif @formats.dxf_index_by_key(get_format_key)
        @formats.dxf_index_by_key(get_format_key)
      else
        @dxf_index = @formats.set_dxf_index_by_key(get_format_key)
      end
    end

    def color(color_code)
      Format.color(color_code)
    end

    #
    # Used in conjunction with the set_xxx_color methods to convert a color
    # string into a number. Color range is 0..63 but we will restrict it
    # to 8..63 to comply with Gnumeric. Colors 0..7 are repeated in 8..15.
    #
    def self.color(color_code)

      colors = Colors::COLORS

      # Return the default color if nil,
      return 0x00 unless color_code

      if color_code.respond_to?(:to_str)
        # Return RGB style colors for processing later.
        return color_code if color_code =~ /^#[0-9A-F]{6}$/i

        # or the color string converted to an integer,
        return colors[color_code.downcase.to_sym] if colors[color_code.downcase.to_sym]

        # or the default color if string is unrecognised,
        return 0x00 if color_code =~ /\D/
      else
        # or an index < 8 mapped into the correct range,
        return color_code + 8 if color_code < 8

        # or the default color if arg is outside range,
        return 0x00 if color_code > 63

        # or an integer in the valid range
        return color_code
      end
    end

    #
    # Set cell alignment.
    #
    def set_align(location)
      return unless location             # No default

      location = location.downcase

      set_text_h_align(1) if location == 'left'
      set_text_h_align(2) if location == 'centre'
      set_text_h_align(2) if location == 'center'
      set_text_h_align(3) if location == 'right'
      set_text_h_align(4) if location == 'fill'
      set_text_h_align(5) if location == 'justify'
      set_text_h_align(6) if location == 'center_across'
      set_text_h_align(6) if location == 'centre_across'
      set_text_h_align(6) if location == 'merge'              # Legacy.
      set_text_h_align(7) if location == 'distributed'
      set_text_h_align(7) if location == 'equal_space'        # S::PE.
      set_text_h_align(7) if location == 'justify_distributed'

      @just_distrib =   1 if location == 'justify_distributed'

      set_text_v_align(1) if location == 'top'
      set_text_v_align(2) if location == 'vcentre'
      set_text_v_align(2) if location == 'vcenter'
      set_text_v_align(3) if location == 'bottom'
      set_text_v_align(4) if location == 'vjustify'
      set_text_v_align(5) if location == 'vdistributed'
      set_text_v_align(5) if location == 'vequal_space'    # S::PE.
    end

    #
    # Set vertical cell alignment. This is required by the set_properties() method
    # to differentiate between the vertical and horizontal properties.
    #
    def set_valign(location)
      set_align(location)
    end

    #
    # Implements the Excel5 style "merge".
    #
    def set_center_across(flag = 1)
      set_text_h_align(6)
    end

    #
    # This was the way to implement a merge in Excel5. However it should have been
    # called "center_across" and not "merge".
    # This is now deprecated. Use set_center_across() or better merge_range().
    #
    def set_merge(merge = 1)
      set_text_h_align(6)
    end

    #
    # Set cells borders to the same style
    #
    def set_border(style)
      set_bottom(style)
      set_top(style)
      set_left(style)
      set_right(style)
    end

    #
    # Set cells border to the same color
    #
    def set_border_color(color)
      set_bottom_color(color)
      set_top_color(color)
      set_left_color(color)
      set_right_color(color)
    end

    #
    # Set the rotation angle of the text. An alignment property.
    #
    def set_rotation(rotation)
      if rotation == 270
        rotation = 255
      elsif rotation >= -90 && rotation <= 90
        rotation = -rotation + 90 if rotation < 0
      else
        raise "Rotation #{rotation} outside range: -90 <= angle <= 90"
        rotation = 0
      end

      @rotation = rotation
    end

    #
    # Set the properties for the hyperlink style. This isn't a public method. To
    # be fixed when styles are supported.
    #
    def set_hyperlink(hyperlink)
      @xf_id = 1

      set_underline(1)
      set_theme(10)
      @hyperlink = hyperlink
    end

    def set_font_info(fonts)
      key = get_font_key

      if fonts[key]
        # Font has already been used.
        @font_index = fonts[key]
        @has_font   = false
      else
        # This is a new font.
        @font_index = fonts.size
        fonts[key]  = fonts.size
        @has_font   = true
      end
    end

    def set_border_info(borders)
      key = get_border_key

      if borders[key]
        # Border has already been used.
        @border_index = borders[key]
        @has_border   = false
      else
        # This is a new border.
        @border_index = borders.size
        borders[key]  = borders.size
        @has_border   = true
      end
    end

    def method_missing(name, *args)  # :nodoc:
      method = "#{name}"

      # Check for a valid method names, i.e. "set_xxx_yyy".
      method =~ /set_(\w+)/ or raise "Unknown method: #{method}\n"

      # Match the attribute, i.e. "@xxx_yyy".
      attribute = "@#{$1}"

      # Check that the attribute exists
      # ........
      if method =~ /set\w+color$/    # for "set_property_color" methods
        value = color(args[0])
      else                            # for "set_xxx" methods
        value = args[0] || 1
      end

      instance_variable_set(attribute, value)
    end

    def color?
      ptrue?(@color)
    end

    def bold?
      ptrue?(@bold)
    end

    def italic?
      ptrue?(@italic)
    end

    def strikeout?
      ptrue?(@font_strikeout)
    end

    def outline?
      ptrue?(@font_outline)
    end

    def shadow?
      ptrue?(@font_shadow)
    end

    def underline?
      ptrue?(@underline)
    end

    def has_border(flag)
      @has_border = flag
    end

    def has_border? # :nodoc:
      @has_border
    end

    def has_dxf_border(flag)
      @has_dxf_border = flag
    end

    def has_dxf_border?
      @has_dxf_border
    end

    def has_font(flag)
      @has_font = flag
    end

    def has_font?
      @has_font
    end

    def has_dxf_font(flag)
      @has_dxf_font = flag
    end

    def has_dxf_font?
      @has_dxf_font
    end

    def has_fill(flag)
      @has_fill = flag
    end

    def has_fill?
      @has_fill
    end

    def has_dxf_fill(flag)
      @has_dxf_fill = flag
    end

    def has_dxf_fill?
      @has_dxf_fill
    end

    def [](attr)
      self.instance_variable_get("@#{attr}")
    end

    def write_font(writer, worksheet, dxf_format = nil) #:nodoc:
      writer.tag_elements('font') do
        # The condense and extend elements are mainly used in dxf formats.
        write_condense(writer) if ptrue?(@font_condense)
        write_extend(writer)   if ptrue?(@font_extend)

        write_font_shapes(writer)

        writer.empty_tag('sz', [ ['val', size] ]) unless dxf_format

        if theme == -1
          # Ignore for excel2003_style
        elsif ptrue?(theme)
          write_color(writer, 'theme', theme)
        elsif ptrue?(@color_indexed)
          write_color(writer, 'indexed', @color_indexed)
        elsif ptrue?(@color)
          color = worksheet.palette_color(@color)
          write_color(writer, 'rgb', color)
        elsif !ptrue?(dxf_format)
          write_color(writer, 'theme', 1)
        end

        unless ptrue?(dxf_format)
          writer.empty_tag('name', [ ['val', @font] ])
          write_font_family_scheme(writer)
        end
      end
    end

    def write_font_rpr(writer, worksheet) #:nodoc:
      writer.tag_elements('rPr') do
        write_font_shapes(writer)
        writer.empty_tag('sz', [ ['val', size] ])

        if ptrue?(theme)
          write_color(writer, 'theme', theme)
        elsif ptrue?(@color)
          color = worksheet.palette_color(@color)
          write_color(writer, 'rgb', color)
        else
          write_color(writer, 'theme', 1)
        end

        writer.empty_tag('rFont', [ ['val', @font] ])
        write_font_family_scheme(writer)
      end
    end

    def border_attributes
      attributes = []

      # Diagonal borders add attributes to the <border> element.
      if diag_type == 1
        attributes << ['diagonalUp',   1]
      elsif diag_type == 2
        attributes << ['diagonalDown', 1]
      elsif diag_type == 3
        attributes << ['diagonalUp',   1]
        attributes << ['diagonalDown', 1]
      end
      attributes
    end

    def xf_attributes
      attributes = [
        ['numFmtId', num_format_index],
        ['fontId'  , font_index],
        ['fillId'  , fill_index],
        ['borderId', border_index],
        ['xfId'    , xf_id]
      ]
      attributes << ['applyNumberFormat', 1] if num_format_index > 0
      # Add applyFont attribute if XF format uses a font element.
      attributes << ['applyFont', 1] if font_index > 0 && !ptrue?(@hyperlink)
      # Add applyFill attribute if XF format uses a fill element.
      attributes << ['applyFill', 1] if fill_index > 0
      # Add applyBorder attribute if XF format uses a border element.
      attributes << ['applyBorder', 1] if border_index > 0

      # Check if XF format has alignment properties set.
      apply_align, align = get_align_properties
      # We can also have applyAlignment without a sub-element.
      attributes << ['applyAlignment', 1] if apply_align || ptrue?(@hyperlink)
      if get_protection_properties || ptrue?(hyperlink)
        attributes << ['applyProtection', 1]
      end

      attributes
    end

    private

    def write_font_shapes(writer)
      writer.empty_tag('b')       if bold?
      writer.empty_tag('i')       if italic?
      writer.empty_tag('strike')  if strikeout?
      writer.empty_tag('outline') if outline?
      writer.empty_tag('shadow')  if shadow?

      # Handle the underline variants.
      write_underline(writer, underline) if underline?

      write_vert_align(writer, 'superscript') if font_script == 1
      write_vert_align(writer, 'subscript')   if font_script == 2
    end

    def write_font_family_scheme(writer)
      if ptrue?(@font_family)
          writer.empty_tag('family', [ ['val', @font_family] ])
      end

      if ptrue?(@font_charset)
        writer.empty_tag('charset', [ ['val', @font_charset] ])
      end

      if @font == 'Calibri' && !ptrue?(@hyperlink)
        writer.empty_tag('scheme', [ ['val', @font_scheme] ])
      end
    end

    #
    # Write the underline font element.
    #
    def write_underline(writer, underline)
      writer.empty_tag('u', write_underline_attributes(underline))
    end

    #
    # Write the underline font element.
    #
    def write_underline_attributes(underline)
      val = 'val'
      # Handle the underline variants.
      case underline
      when 2
        [ [val, 'double'] ]
      when 33
        [ [val, 'singleAccounting'] ]
      when 34
        [ [val, 'doubleAccounting'] ]
      else
        []
      end
    end

    #
    # Write the <vertAlign> font sub-element.
    #
    def write_vert_align(writer, val) #:nodoc:
      writer.empty_tag('vertAlign', [ ['val', val] ])
    end

    #
    # Write the <condense> element.
    #
    def write_condense(writer)
      writer.empty_tag('condense', [ ['val', 0] ])
    end

    #
    # Write the <extend> element.
    #
    def write_extend(writer)
      writer.empty_tag('extend', [ ['val', 0] ])
    end
  end
end