VitNX_ScrollBar.OnMouseMove Method

protected override void OnMouseMove(MouseEventArgs e)
 {
     base.OnMouseMove(e);
     if (!_isScrolling)
     {
         var thumbHot = _thumbArea.Contains(e.Location);
         if (_thumbHot != thumbHot)
         {
             _thumbHot = thumbHot;
             Invalidate();
         }
         var upArrowHot = _upArrowArea.Contains(e.Location);
         if (_upArrowHot != upArrowHot)
         {
             _upArrowHot = upArrowHot;
             Invalidate();
         }
         var downArrowHot = _downArrowArea.Contains(e.Location);
         if (_downArrowHot != downArrowHot)
         {
             _downArrowHot = downArrowHot;
             Invalidate();
         }
     }
     if (_isScrolling)
     {
         if (e.Button != MouseButtons.Left)
         {
             OnMouseUp(null);
             return;
         }
         var difference = new Point(e.Location.X - _initialContact.X, e.Location.Y - _initialContact.Y);
         if (_scrollOrientation == VitNX_ScrollOrientation.Vertical)
         {
             var thumbPos = (_initialValue - _trackArea.Top);
             var newPosition = thumbPos + difference.Y;
             ScrollToPhysical(newPosition);
         }
         else
         {
             if (_scrollOrientation == VitNX_ScrollOrientation.Horizontal)
             {
                 var thumbPos = (_initialValue - _trackArea.Left);
                 var newPosition = thumbPos + difference.X;
                 ScrollToPhysical(newPosition);
             }
         }
         UpdateScrollBar();
     }
 }