#--
# $Id: stylable.rb,v 1.2 2005/12/31 14:41:04 rmagick Exp $
# Copyright (C) 2006 Timothy P. Hunter
#++

class Magick::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 }
            return 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:
        # [: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.
        # [: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'
        def styles(styles)
            @styles.set(styles)
            yield(self) if block_given?
            self
        end

    end     # module Stylable

end     # class Magick::RVG

