character.rb in tanuki_emoji-0.2.0

- old
+ new

@@ -4,10 +4,23 @@
   # Character represents an Emoji character or sequence which can be formed by one or more Unicode code points
   # respectively which combined form a unique pictographic representation (known as Emoji)
   #
   # @see https://www.unicode.org/reports/tr51/
   class Character
+    IMAGE_PREFIX = 'emoji_u'
+    IMAGE_EXTENSION = '.png'
+    FLAG_REGEXP = /[🇦-🇿]{2}/u.freeze
+
+    # This denotes a "color" or "emoji" version
+    EMOJI_VARIATION_SELECTOR = 0xFE0F
+
+    # This denotes a "plain" (black/white) or "textual" version
+    PLAIN_VARIATION_SELECTOR = 0xFE0E
+
+    # Zero Width Joiner is used in sequences to indicate they should all be evaluated and displayed as a single thing
+    ZWJ_TAG = 0x200D
+
     attr_reader :name, :codepoints, :codepoints_alternates, :alpha_code, :aliases, :description
 
     # @param [String] name
     # @param [String] codepoints
     # @param [String] alpha_code
@@ -37,9 +50,29 @@
     # Return a Hex formatted version of the Unicode code points
     #
     # @return [String] Hex formatted version of the unicode
     def hex
       unicode_to_hex(codepoints).join('-')
+    end
+
+    # Generate the image name to be used as fallback for this character
+    #
+    # @return [String] image name with extension
+    def image_name
+      # Noto doesn't ship flags as part of regular hex-named files
+      # Flags are stored in a separate third-party folder and follow ISO-3166-1 codes
+      # @see http://en.wikipedia.org/wiki/ISO_3166-1
+      return alpha_code.tr(':', '').sub('flag_', '').upcase + IMAGE_EXTENSION if flag?
+
+      # Noto omits Emoji Variation Selector on their resources file names
+      IMAGE_PREFIX + unicode_to_hex(codepoints).reject { |i| i == EMOJI_VARIATION_SELECTOR.to_s(16) }.join('_') + IMAGE_EXTENSION
+    end
+
+    # Return whether current character represents a flag or not
+    #
+    # @return [Boolean] whether character represents a flag or not
+    def flag?
+      codepoints.match?(FLAG_REGEXP)
     end
 
     def to_s
       codepoints
     end