code: def _front_delta(self):
          
          if self.flags & self.NO_MOVE:
              return Separator(0, 0)
  
          if self.clicked and self.hovered:  # the mouse is over the button
              delta = 2
  
          elif self.hovered and not self.flags & self.NO_HOVER:
              delta = 0
  
          else:
              delta = 0
  
          return Separator(delta, delta)
docs: Return the offset of the colored part.