title: flip scrollbar WPF
body: <p>Hi
  I am building a control that shows a ruler from 0 to a maximum. The 0 value is at the bottom and the maximum is in a higher y then the 0(The maximum is not visible until we scroll to it).
  The problem is that while 0 is down and the maximum is up. The 0 value of the scroll bar is up and the maximum is down.
  I want that the scroll bar will be flipped.
  How can I do that ?</p>