title: Keyboard shortcut to an action in SWT
body: <p>How to define a keyboard shortcut (accelerator) to an action associated with a context menu item of <code>TreeViewer</code> or <code>TableViewer</code> (or any control in general).</p>
  
  <p>I have trees and tables of different kind of objects and I have generic actions like "move up", "move down", "expand" or "collapse". I created context menus for table or tree controls, but I want the user to be able to call actions without necessity of right clicking on selection (or without necessity of using mouse in general). For example "Move up" action should be called when the viewer is focused and user presses <kbd>Alt</kbd>+<kbd>&uarr;</kbd>.
  Setting accelerator to that actions does not work. I do not also want to add the actions to main menu bar (like Edit menu etc.).</p>