diff options
Diffstat (limited to 'app/assets/javascripts/emoji/support/is_emoji_unicode_supported.js')
-rw-r--r-- | app/assets/javascripts/emoji/support/is_emoji_unicode_supported.js | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/app/assets/javascripts/emoji/support/is_emoji_unicode_supported.js b/app/assets/javascripts/emoji/support/is_emoji_unicode_supported.js new file mode 100644 index 00000000000..3fd23efa9f8 --- /dev/null +++ b/app/assets/javascripts/emoji/support/is_emoji_unicode_supported.js @@ -0,0 +1,120 @@ +// On Windows, flags render as two-letter country codes, see http://emojipedia.org/flags/ +const flagACodePoint = 127462; // parseInt('1F1E6', 16) +const flagZCodePoint = 127487; // parseInt('1F1FF', 16) +function isFlagEmoji(emojiUnicode) { + const cp = emojiUnicode.codePointAt(0); + // Length 4 because flags are made of 2 characters which are surrogate pairs + return emojiUnicode.length === 4 && cp >= flagACodePoint && cp <= flagZCodePoint; +} + +// Chrome <57 renders keycaps oddly +// See https://bugs.chromium.org/p/chromium/issues/detail?id=632294 +// Same issue on Windows also fixed in Chrome 57, http://i.imgur.com/rQF7woO.png +function isKeycapEmoji(emojiUnicode) { + return emojiUnicode.length === 3 && emojiUnicode[2] === '\u20E3'; +} + +// Check for a skin tone variation emoji which aren't always supported +const tone1 = 127995;// parseInt('1F3FB', 16) +const tone5 = 127999;// parseInt('1F3FF', 16) +function isSkinToneComboEmoji(emojiUnicode) { + return emojiUnicode.length > 2 && Array.from(emojiUnicode).some((char) => { + const cp = char.codePointAt(0); + return cp >= tone1 && cp <= tone5; + }); +} + +// macOS supports most skin tone emoji's but +// doesn't support the skin tone versions of horse racing +const horseRacingCodePoint = 127943;// parseInt('1F3C7', 16) +function isHorceRacingSkinToneComboEmoji(emojiUnicode) { + const firstCharacter = Array.from(emojiUnicode)[0]; + return firstCharacter && firstCharacter.codePointAt(0) === horseRacingCodePoint && + isSkinToneComboEmoji(emojiUnicode); +} + +// Check for `family_*`, `kiss_*`, `couple_*` +// For ex. Windows 8.1 Firefox 51.0.1, doesn't support these +const zwj = 8205; // parseInt('200D', 16) +const personStartCodePoint = 128102; // parseInt('1F466', 16) +const personEndCodePoint = 128105; // parseInt('1F469', 16) +function isPersonZwjEmoji(emojiUnicode) { + let hasPersonEmoji = false; + let hasZwj = false; + Array.from(emojiUnicode).forEach((character) => { + const cp = character.codePointAt(0); + if (cp === zwj) { + hasZwj = true; + } else if (cp >= personStartCodePoint && cp <= personEndCodePoint) { + hasPersonEmoji = true; + } + }); + + return hasPersonEmoji && hasZwj; +} + +// Helper so we don't have to run `isFlagEmoji` twice +// in `isEmojiUnicodeSupported` logic +function checkFlagEmojiSupport(unicodeSupportMap, emojiUnicode) { + const isFlagResult = isFlagEmoji(emojiUnicode); + return ( + (unicodeSupportMap.flag && isFlagResult) || + !isFlagResult + ); +} + +// Helper so we don't have to run `isSkinToneComboEmoji` twice +// in `isEmojiUnicodeSupported` logic +function checkSkinToneModifierSupport(unicodeSupportMap, emojiUnicode) { + const isSkinToneResult = isSkinToneComboEmoji(emojiUnicode); + return ( + (unicodeSupportMap.skinToneModifier && isSkinToneResult) || + !isSkinToneResult + ); +} + +// Helper func so we don't have to run `isHorceRacingSkinToneComboEmoji` twice +// in `isEmojiUnicodeSupported` logic +function checkHorseRacingSkinToneComboEmojiSupport(unicodeSupportMap, emojiUnicode) { + const isHorseRacingSkinToneResult = isHorceRacingSkinToneComboEmoji(emojiUnicode); + return ( + (unicodeSupportMap.horseRacing && isHorseRacingSkinToneResult) || + !isHorseRacingSkinToneResult + ); +} + +// Helper so we don't have to run `isPersonZwjEmoji` twice +// in `isEmojiUnicodeSupported` logic +function checkPersonEmojiSupport(unicodeSupportMap, emojiUnicode) { + const isPersonZwjResult = isPersonZwjEmoji(emojiUnicode); + return ( + (unicodeSupportMap.personZwj && isPersonZwjResult) || + !isPersonZwjResult + ); +} + +// Takes in a support map and determines whether +// the given unicode emoji is supported on the platform. +// +// Combines all the edge case tests into a one-stop shop method +function isEmojiUnicodeSupported(unicodeSupportMap = {}, emojiUnicode, unicodeVersion) { + const isOlderThanChrome57 = unicodeSupportMap.meta && unicodeSupportMap.meta.isChrome && + unicodeSupportMap.meta.chromeVersion < 57; + + // For comments about each scenario, see the comments above each individual respective function + return unicodeSupportMap[unicodeVersion] && + !(isOlderThanChrome57 && isKeycapEmoji(emojiUnicode)) && + checkFlagEmojiSupport(unicodeSupportMap, emojiUnicode) && + checkSkinToneModifierSupport(unicodeSupportMap, emojiUnicode) && + checkHorseRacingSkinToneComboEmojiSupport(unicodeSupportMap, emojiUnicode) && + checkPersonEmojiSupport(unicodeSupportMap, emojiUnicode); +} + +export { + isEmojiUnicodeSupported as default, + isFlagEmoji, + isKeycapEmoji, + isSkinToneComboEmoji, + isHorceRacingSkinToneComboEmoji, + isPersonZwjEmoji, +}; |