title: How to detect "ALT + TAB" key event in SWT Shell?
body: <p>I want to detect the key event <kbd>Alt</kbd> + <kbd>Tab</kbd> Key in SWT Shell. At the time of tab key pressed it must be required to pressed <kbd>Alt</kbd> key.
  I have tried using the following but its not detect <kbd>Alt</kbd> + <kbd>Tab</kbd>.</p>
  
  <pre class="lang-java prettyprint-override"><code>public static void main(String[] args) 
    {
      Display display = new Display ();
      final Shell shell = new Shell (display);
      final Color green = display.getSystemColor (SWT.COLOR_GREEN);
      final Color orig = shell.getBackground();
  
      display.addFilter(SWT.KeyDown, new Listener() {
  
          public void handleEvent(Event e) {
              if(((e.stateMask &amp; SWT.ALT) == SWT.ALT) &amp;&amp; (e.keyCode == SWT.TAB))
              {
                  System.out.println("From Display I am the Key down !!" );
              }
          }
      });
      shell.addKeyListener(new KeyListener() {
        public void keyReleased(KeyEvent e) {
            if(((e.stateMask &amp; SWT.ALT) == SWT.ALT) &amp;&amp; (e.keyCode == SWT.TAB))
            {
                shell.setBackground(orig);
                System.out.println("Key up ALT +TAB Detact !!");
            }
        }
        public void keyPressed(KeyEvent e) {
            if(((e.stateMask &amp; SWT.ALT) == SWT.ALT) &amp;&amp; (e.keyCode ==  SWT.TAB))
            {
                shell.setBackground(green);
                System.out.println("Key down  ALT +TAB Detact!!");
            }
        }
     });
      shell.setSize (200, 200);
      shell.open ();
      while (!shell.isDisposed()) {
      if (!display.readAndDispatch ()) display.sleep ();
      }
      display.dispose ();
  }
  </code></pre>