Initial commit. State 04.2021.

wp-admin/js/language-chooser.js

@@ -0,0 +1,26 @@
+jQuery( function($) {
+
+var select = $( '#language' ),
+	submit = $( '#language-continue' );
+
+if ( ! $( 'body' ).hasClass( 'language-chooser' ) ) {
+	return;
+}
+
+select.focus().on( 'change', function() {
+	var option = select.children( 'option:selected' );
+	submit.attr({
+		value: option.data( 'continue' ),
+		lang: option.attr( 'lang' )
+	});
+});
+
+$( 'form' ).submit( function() {
+	// Don't show a spinner for English and installed languages,
+	// as there is nothing to download.
+	if ( ! select.children( 'option:selected' ).data( 'installed' ) ) {
+		$( this ).find( '.step .spinner' ).css( 'visibility', 'visible' );
+	}
+});
+
+});