title: Detect left and right movement using UILongPressGestureRecognizer?
body: <p>From what I already know from this question <a href="https://stackoverflow.com/questions/11777281/detecting-the-direction-of-pan-gesture-in-ios">Detecting the direction of PAN gesture in iOS</a> answered by H2CO3, you can detect left or right movement in <code>UIPanGestureRecognizer</code> by using:</p>
  
  <pre><code>CGPoint vel = [gesture velocityInView:self.view];
  if (vel.x &gt; 0)
   {
       // user dragged towards the right
   }
   else
   {
       // user dragged towards the left
   }
  </code></pre>
  
  <p>I want to detect left or right movement when user tap and hold a button similar to code above by using <code>UILongPressGestureRecognizer</code> when user entered <code>UIGestureRecognizerStateChanged</code> state, but it seems I can't simply using <code>velocityInView</code> to make things work in my case.</p>
  
  <p>Anyone can help me?</p>