init

wp-content/themes/twentysixteen/js/keyboard-image-navigation.js

@@ -0,0 +1,26 @@
+/**
+ * Twenty Sixteen keyboard support for image navigation.
+ */
+
+( function( $ ) {
+	$( document ).on( 'keydown.twentysixteen', function( e ) {
+		var url = false;
+
+		// Left arrow key code.
+		if ( 37 === e.which ) {
+			url = $( '.nav-previous a' ).attr( 'href' );
+
+		// Right arrow key code.
+		} else if ( 39 === e.which ) {
+			url = $( '.nav-next a' ).attr( 'href' );
+
+		// Other key code.
+		} else {
+			return;
+		}
+
+		if ( url && ! $( 'textarea, input' ).is( ':focus' ) ) {
+			window.location = url;
+		}
+	} );
+} )( jQuery );