ass: add support classes for text styling

Author: pigoz

lib/ass/color.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Ass
+  # Represents a SubStationAlpha Color
+  class Color
+    {
+      black: [0, 0, 0],
+      white: [255, 255, 255],
+      red: [255, 0, 0],
+      green: [0, 255, 0],
+      yellow: [0, 255, 255],
+    }.each do |k, v|
+      define_singleton_method(k) { new(*v) }
+    end
+
+    # @param red [Integer] 0 to 255
+    # @param green [Integer] 0 to 255
+    # @param blue [Integer] 0 to 255
+    def initialize(red, green, blue)
+      @rgb = [red, green, blue]
+    end
+
+    # @return [String] ASS script representation
+    def to_script
+      s = @rgb.map(&method(:to_hex)).join("")
+      "&H#{s}&"
+    end
+
+    private
+
+    def to_hex(component)
+      component.to_s(16).upcase.rjust(2, "0")
+    end
+  end
+end

lib/ass/text.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Ass
+  # Represents a SubStationAlpha styled String
+  class Text
+    def initialize(text)
+      @text = text
+      @style = {}
+    end
+
+    # @param size [Integer]
+    # @return [Text]
+    def font_size(size)
+      @style.merge!(fs: size)
+      self
+    end
+
+    # @param size [Integer]
+    # @param color [Color]
+    # @return [Text]
+    def border(size, color)
+      @style.merge!(bord: size, "3c": color.to_script)
+      self
+    end
+
+    # @param color [Color]
+    # @return [Text]
+    def color(color)
+      @style.merge!("1c": color.to_script)
+      self
+    end
+
+    # @return [String] ASS script representation
+    def to_script
+      [@style.map { |k, v| "{\\#{k}#{v}}" }.join, @text].join
+    end
+  end
+end

lib/mpv.rb

@@ -5,6 +5,9 @@
 module MPV
 end
 
+require_relative "ass/color"
+require_relative "ass/text"
+
 require_relative "mpv/exceptions"
 require_relative "mpv/utils"
 require_relative "mpv/client"

spec/ass_color_spec.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe Ass::Color do
+  it "converts white" do
+    expect(Ass::Color.white.to_script).to eql("&HFFFFFF&")
+  end
+end

spec/ass_text_spec.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe Ass::Text do
+  it "deals with styled text" do
+    colors = Ass::Color
+    s = Ass::Text.new("適当")
+    s = s.border(1, colors.black).color(colors.white).font_size(40)
+    expect(s.to_script).to eql("{\\bord1}{\\3c&H000000&}{\\1c&HFFFFFF&}{\\fs40}適当")
+  end
+end