wp/wp-content/themes/twentysixteen/js/skip-link-focus-fix.js
changeset 7 cf61fcea0001
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-content/themes/twentysixteen/js/skip-link-focus-fix.js	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,36 @@
+/**
+ * Makes "skip to content" link work correctly in IE9, Chrome, and Opera
+ * for better accessibility.
+ *
+ * @link http://www.nczonline.net/blog/2013/01/15/fixing-skip-to-content-links/
+ */
+
+ ( function() {
+	var isWebkit = navigator.userAgent.toLowerCase().indexOf( 'webkit' ) > -1,
+		isOpera  = navigator.userAgent.toLowerCase().indexOf( 'opera' )  > -1,
+		isIE     = navigator.userAgent.toLowerCase().indexOf( 'msie' )   > -1;
+
+	if ( ( isWebkit || isOpera || isIE ) && document.getElementById && window.addEventListener ) {
+		window.addEventListener( 'hashchange', function() {
+			var id = location.hash.substring( 1 ),
+				element;
+
+			if ( ! ( /^[A-z0-9_-]+$/.test( id ) ) ) {
+				return;
+			}
+
+			element = document.getElementById( id );
+
+			if ( element ) {
+				if ( ! ( /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) ) {
+					element.tabIndex = -1;
+				}
+
+				element.focus();
+
+				// Repositions the window on jump-to-anchor to account for admin bar and border height.
+				window.scrollBy( 0, -53 );
+			}
+		}, false );
+	}
+} )();