   }
   
   func calculateTabBarPosition(position: Int) {
+    self.manualTransition = true
     if position <= 0 {
       self.swipeBackCancelled = true
       self.hideTabBarOnCancel()

    { (done) in
      if done {
        self.swipeBackCancelled = false
      }
    }
  }
  
  func showTabBar() {
    self.tabBarBottom.constant = CGFloat(self.bottomPosition)
    UIView.animateWithDuration(self.animationDuration) {
      self.view.layoutIfNeeded()
    }
  }
  

  
  func hideTabBar() {
    self.tabBarBottom.constant = -self.tabBarHeight.constant
    UIView.animateWithDuration(self.animationDuration, animations: {
      self.view.layoutIfNeeded()
    }) { (done) in
      if done {
        self.tabBarVisible = false
      }
    }
  }
  
