+ * Return the first element of $svgLanguages that matches $userPreferredLanguage
+ *
+ * @see https://www.w3.org/TR/SVG/struct.html#SystemLanguageAttribute
+ * @param string $userPreferredLanguage
+ * @param array $svgLanguages
+ * @return string|null
+ */
+ public function getMatchedLanguage( $userPreferredLanguage, array $svgLanguages ) {
+ foreach ( $svgLanguages as $svgLang ) {
+ if ( strcasecmp( $svgLang, $userPreferredLanguage ) === 0 ) {
+ return $svgLang;
+ }
+ $trimmedSvgLang = $svgLang;
+ while ( strpos( $trimmedSvgLang, '-' ) !== false ) {
+ $trimmedSvgLang = substr( $trimmedSvgLang, 0, strrpos( $trimmedSvgLang, '-' ) );
+ if ( strcasecmp( $trimmedSvgLang, $userPreferredLanguage ) === 0 ) {
+ return $svgLang;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * What language to render file in if none selected
+ *
+ * @param File $file Language code
+ * @return string