title: Keep Tabbing if Tab Key is not released
body: <p>Currently I am tabbing on <strong>PreviewKeyDown</strong>, using something like this: </p>
  
  <pre><code>var focusedElement = Keyboard.FocusedElement as FrameworkElement;
              var direction = GetDirection();
              focusedElement?.MoveFocus(new TraversalRequest(direction));
   static FocusNavigationDirection GetDirection()
          {
              return (Keyboard.Modifiers.HasFlag(ModifierKeys.Shift))
                  ? FocusNavigationDirection.Previous
                  : FocusNavigationDirection.Next;
          }
  </code></pre>
  
  <p>this works great, every time the user presses Tab, we Tab. 
  However it's missing a functionality: I would like it to keep tabbing if the user has not released the Tab Key. Example Press and hold Tab key down on in Excel</p>
  
  <p>I wanted to know if there is recommended/standard/out of the box way to achieve this behavior? </p>
  
  <p>Or do I have to implement this myself : which I was planning to do using a  DispatcherTimer and then Tabbing every time on tick and then stopping the timer on KeyUp. </p>