title: Toggling the state of a menu item
body: <p>I have an Eclipse RCP app I'm working on. It has some view-specific menus and one of the menu items is an item which I would like to display a tick next to when the corresponding functionality is enabled. Similarly, the next time the item is selected, the item should become unticked to reflect that the corresponding functionality is disabled.</p>
  
  <p>My question is this: how do I set the toggle state of these menu items? I have an IHandler to deal with the event when the menu item is selected but I'm unsure how to update the GUI element itself.</p>
  
  <p>Does the StackOverflow community have any thoughts on how I might solve this?</p>