VitNX_ScrollBar.OnMouseDown Method

protected override void OnMouseDown(MouseEventArgs e)
 {
     base.OnMouseDown(e);
     if (_thumbArea.Contains(e.Location) && e.Button == MouseButtons.Left)
     {
         _isScrolling = true;
         _initialContact = e.Location;
         _initialValue = _scrollOrientation == VitNX_ScrollOrientation.Vertical ? _thumbArea.Top : _thumbArea.Left;
         Invalidate();
         return;
     }
 
     if (_upArrowArea.Contains(e.Location) && e.Button == MouseButtons.Left)
     {
         _upArrowClicked = true;
         _scrollTimer.Enabled = true;
         Invalidate();
         return;
     }
 
     if (_downArrowArea.Contains(e.Location) && e.Button == MouseButtons.Left)
     {
         _downArrowClicked = true;
         _scrollTimer.Enabled = true;
         Invalidate();
         return;
     }
 
     if (_trackArea.Contains(e.Location) && e.Button == MouseButtons.Left)
     {
         if (_scrollOrientation == VitNX_ScrollOrientation.Vertical)
         {
             var modRect = new Rectangle(_thumbArea.Left, _trackArea.Top, _thumbArea.Width, _trackArea.Height);
             if (!modRect.Contains(e.Location))
                 return;
         }
         else if (_scrollOrientation == VitNX_ScrollOrientation.Horizontal)
         {
             var modRect = new Rectangle(_trackArea.Left, _thumbArea.Top, _trackArea.Width, _thumbArea.Height);
             if (!modRect.Contains(e.Location))
                 return;
         }
         if (_scrollOrientation == VitNX_ScrollOrientation.Vertical)
         {
             var loc = e.Location.Y;
             loc -= _upArrowArea.Bottom - 1;
             loc -= _thumbArea.Height / 2;
             ScrollToPhysical(loc);
         }
         else
         {
             var loc = e.Location.X;
             loc -= _upArrowArea.Right - 1;
             loc -= _thumbArea.Width / 2;
             ScrollToPhysical(loc);
         }
         _isScrolling = true;
         _initialContact = e.Location;
         _thumbHot = true;
         _initialValue = _scrollOrientation == VitNX_ScrollOrientation.Vertical ? _thumbArea.Top : _thumbArea.Left;
         Invalidate();
         return;
     }
 }