title: Detect printable keys
body: <p>I need to detect whether the key which has just been pressed is a printable key, like a character, possibly accented, a number, a space, a punctuation symbol and so on, or a non printable key, like ENTER, TAB or DELETE.</p>
  
  <p>Is there a reliable way to do this in Javascript, other than listing all non printable keys and hope not to forget some?</p>