title: Differentiate between focus event triggered by keyboard/mouse
body: <p>I'm using jquery ui autocomplete and want to decipher between focus events triggered by keyboard interaction and mouse interaction. How would I go about this?</p>
  
  <pre><code>$('input').autocomplete({
      source: function(request, response) {
          ...
      },
      focus: function(event, ui) {
          // If focus triggered by keyboard interaction
              alert('do something');
          // If focus event triggered by mouse interaction
              alert('do something else');
      }
  });
  </code></pre>
  
  <p>Thanks</p>