title: How to know mouseDragged direction - when it's up or down?
body: <p>Finishing to create custom scrollbar, and the question is:</p>
  
  <pre><code>addMouseMotionListener(new MouseMotionAdapter() {
      @Override
      public void mouseDragged(MouseEvent e) {
  
          //How to know mouse direction - up or down?
  
      }
  });
  </code></pre>
  
  <p>Maybe there is some simple method, or I have to do it manually?</p>