From 2d4348c50d32cb9c0228f5cf0fd7779c56f5b619 Mon Sep 17 00:00:00 2001
From: Stanislav Dmitrenko <7953703+avently@users.noreply.github.com>
Date: Tue, 30 Aug 2022 10:50:44 +0300
Subject: [PATCH] Regex for Emoji (#982)

---
 .../app/views/chat/item/EmojiItemView.kt        | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/apps/android/app/src/main/java/chat/simplex/app/views/chat/item/EmojiItemView.kt b/apps/android/app/src/main/java/chat/simplex/app/views/chat/item/EmojiItemView.kt
index 8d6e59edc1..7ac5e0ca7e 100644
--- a/apps/android/app/src/main/java/chat/simplex/app/views/chat/item/EmojiItemView.kt
+++ b/apps/android/app/src/main/java/chat/simplex/app/views/chat/item/EmojiItemView.kt
@@ -31,12 +31,19 @@ fun EmojiText(text: String) {
   Text(s, style = if (s.codePoints().count() < 4) largeEmojiFont else mediumEmojiFont)
 }
 
-private fun isSimpleEmoji(c: Int): Boolean = c > 0x238C
+// https://stackoverflow.com/a/46279500
+private const val emojiStr = "^(" +
+    "(?:[\\u2700-\\u27bf]|" +
+    "(?:[\\ud83c\\udde6-\\ud83c\\uddff]){2}|" +
+    "[\\ud800\\udc00-\\uDBFF\\uDFFF]|[\\u2600-\\u26FF])[\\ufe0e\\ufe0f]?(?:[\\u0300-\\u036f\\ufe20-\\ufe23\\u20d0-\\u20f0]|[\\ud83c\\udffb-\\ud83c\\udfff])?" +
+    "(?:\\u200d(?:[^\\ud800-\\udfff]|" +
+    "(?:[\\ud83c\\udde6-\\ud83c\\uddff]){2}|" +
+    "[\\ud800\\udc00-\\uDBFF\\uDFFF]|[\\u2600-\\u26FF])[\\ufe0e\\ufe0f]?(?:[\\u0300-\\u036f\\ufe20-\\ufe23\\u20d0-\\u20f0]|[\\ud83c\\udffb-\\ud83c\\udfff])?)*|" +
+    "[\\u0023-\\u0039]\\ufe0f?\\u20e3|\\u3299|\\u3297|\\u303d|\\u3030|\\u24c2|[\\ud83c\\udd70-\\ud83c\\udd71]|[\\ud83c\\udd7e-\\ud83c\\udd7f]|\\ud83c\\udd8e|[\\ud83c\\udd91-\\ud83c\\udd9a]|[\\ud83c\\udde6-\\ud83c\\uddff]|[\\ud83c\\ude01-\\ud83c\\ude02]|\\ud83c\\ude1a|\\ud83c\\ude2f|[\\ud83c\\ude32-\\ud83c\\ude3a]|[\\ud83c\\ude50-\\ud83c\\ude51]|\\u203c|\\u2049|[\\u25aa-\\u25ab]|\\u25b6|\\u25c0|[\\u25fb-\\u25fe]|\\u00a9|\\u00ae|\\u2122|\\u2139|\\ud83c\\udc04|[\\u2600-\\u26FF]|\\u2b05|\\u2b06|\\u2b07|\\u2b1b|\\u2b1c|\\u2b50|\\u2b55|\\u231a|\\u231b|\\u2328|\\u23cf|[\\u23e9-\\u23f3]|[\\u23f8-\\u23fa]|\\ud83c\\udccf|\\u2934|\\u2935|[\\u2190-\\u21ff]" +
+    ")+$" // Multiple matches with emojis where one follows another without interruptions from other characters
+private val emojiRegex = Regex(emojiStr)
 
-fun isEmoji(c: Int): Boolean = isSimpleEmoji(c) // || isCombinedIntoEmoji(c)
-
-// TODO count perceived emojis, possibly using icu4j
 fun isShortEmoji(str: String): Boolean {
   val s = str.trim()
-  return s.codePoints().count() in 1..5 && s.codePoints().allMatch(::isEmoji)
+  return s.codePoints().count() in 1..5 && emojiRegex.matches(str)
 }