Issue 8458: Display big emojis

Fixes #8458

src/Content/Text/BBCode.php

@@ -1724,7 +1724,15 @@ class BBCode
 
 		// Replace non graphical smilies for external posts
 		if (!$nosmile && !$for_plaintext) {
-			$text = Smilies::replace($text);
+			$oldtext = $text;
+			$text = Smilies::replace($text);			
+			if (DI::config()->get('system', 'big_emojis') && ($simple_html != self::DIASPORA) && ($oldtext != $text)) {
+				$conv = html_entity_decode(str_replace([' ', "\n", "\r"], '', $text));
+				// Emojis are always 4 byte Unicode characters
+				if (strlen($conv) / mb_strlen($conv) == 4) {
+					$text = '<span style="font-size: xx-large; line-height: initial;">' . $text . '</span>';
+				}
+			}
 		}
 
 		if (!$for_plaintext) {

static/defaults.config.php

@@ -103,6 +103,10 @@ return [
 		// chose "Remember me" when logging in is considered logged out.
 		'auth_cookie_lifetime' => 7,
 
+		// big_emojis (Boolean)
+		// Display "Emoji Only" posts in big.
+		'big_emojis' => false,
+
 		// block_local_dir (Boolean)
 		// Deny public access to the local user directory.
 		'block_local_dir' => false,