Highlight table row only when tabbing

Question

I'd like to add highlighting when tabbing to a row in my table. Issue I'm having is that the focusin function encompasses both mouse click events and tab key. I'd only like this to occur when tabbing. Still new to jQuery/js. Suggestions please?

$( "tr" ).focusin( 
        function() { $(this).addClass("highlight"); } ).focusout( 
                function() {$(this).removeClass("highlight");
});