#--
# $Id: stylable.rb,v 1.7 2009/02/28 23:52:28 rmagick Exp $
# Copyright (C) 2009 Timothy P. Hunter
#++
module Magick
  class RVG
    #:stopdoc:
    STYLES = [:clip_path, :clip_rule, :fill, :fill_opacity, :fill_rule, :font,
          :font_family, :font_size, :font_stretch, :font_style, :font_weight,
          :opacity, :stroke, :stroke_dasharray, :stroke_dashoffset, :stroke_linecap,
          :stroke_linejoin, :stroke_miterlimit, :stroke_opacity, :stroke_width,
          :text_anchor, :text_decoration,
          :glyph_orientation_vertical, :glyph_orientation_horizontal,
          :letter_spacing, :word_spacing, :baseline_shift, :writing_mode]

    Styles = Struct.new(*STYLES)

    # Styles is a Struct class with a couple of extra methods
    class Styles
      def set(styles)
        begin
          styles.each_pair do |style, value|
            begin
              self[style] = value
            rescue NoMethodError
              raise ArgumentError, "unknown style `#{style}'"
            end
          end
        rescue NoMethodError
          raise ArgumentError, "style arguments must be in the form `style => value'"
        end
        self
      end

      # Iterate over the style names. Yield for each style that has a value.
      def each_value
        each_pair do |style, value|
          yield(style, value) if value
        end
      end

      # The "usual" deep_copy method doesn't copy a Struct correctly.
      def deep_copy(h=nil)
        copy = Styles.new
        each_pair { |style, value| copy[style] = value }
        copy
      end
    end     # class Styles

    #:startdoc:

    # This module is mixed into classes that can have styles.
    module Stylable
      private

      # For each style that has a value, add a style primitive to the gc.
      # Use splat to splat out Array arguments such as stroke_dasharray.
      def add_style_primitives(gc)
        @styles.each_value do |style, value|
          if value.respond_to? :add_primitives
            value.add_primitives(gc, style)
          else
            gc.__send__(style, *value)
          end
        end
      end

      def initialize
        super
        @styles = Styles.new
      end

      public

      # This method can be used with any RVG, Group, Use, Text, or
      # shape object. The argument is a hash. The style names are
      # the hash keys. The style names and values are:
      # [:baseline_shift] modify the text baseline
      # [:clip_path] clipping path defined by clip_path
      # [:clip_rule] 'evenodd' or 'nozero'
      # [:fill] color name
      # [:fill_opacity] the fill opacity, 0.0<=N<=1.0
      # [:fill_rule] 'evenodd' or 'nozero'
      # [:font] font name or font file name
      # [:font_family] font family name, ex. 'serif'
      # [:font_size] font size in points
      # [:font_stretch] 'normal','ultra_condensed','extra_condensed',
      #                 'condensed','semi_condensed','semi_expanded',
      #                 'expanded','extra_expanded','ultra_expanded'
      # [:font_style] 'normal','italic','oblique'
      # [:font_weight] 'normal','bold','bolder','lighter', or
      #                a multiple of 100 between 100 and 900.
      # [:glyph_orientation_horizontal] 0, 90, 180, 270
      # [:glyph_orientation_vertical] 0, 90, 180, 270
      # [:letter_spacing] modify the spacing between letters
      # [:opacity] both fill and stroke opacity, 0.0<=N<=1.0
      # [:stroke] color name
      # [:stroke_dasharray] dash pattern (Array)
      # [:stroke_dashoffset] initial distance into dash pattern
      # [:stroke_linecap] 'butt', 'round', 'square'
      # [:stroke_linejoin] 'miter', 'round', 'bevel'
      # [:stroke_miterlimit] miter length constraint
      # [:stroke_opacity] the stroke opacity, 0.0<=N<=1.0
      # [:stroke_width] stroke width
      # [:text_anchor] 'start','middle','end'
      # [:text_decoration] 'none','underline','overline','line_through'
      # [:word_spacing] modify the spacing between words
      # [:writing_mode] 'lr-tb', 'lr', 'rt-tb', 'rl', 'tb-rl', 'tb'
      def styles(styles)
        @styles.set(styles)
        yield(self) if block_given?
        self
      end
    end     # module Stylable
  end # class RVG
end # module Magick
