let initialFrame = CGRect(x: xpos, y: -310, width: 300, height: 300)

let firstView = UIView()
firstView.backgroundColor = .red
firstView.frame = initialFrame

let secondView = UIView()
secondView.backgroundColor = .white
secondView.frame = initialFrame
secondView.isHidden = false


self.view.addSubview(firstView)
self.view.addSubview(secondView)


// Here I try to move the views on screen while fliping them
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseOut, animations: {
    secondView.center = self.view.center
    firstView.center = self.view.center
    self.flip(firstView: firstView, secondView: secondView)
}, completion: nil)



// This function flips the views vertically while it animates the transition from the first to the second view
fileprivate func flip(firstView: UIView, secondView: UIView) {
    let transitionOptions: UIViewAnimationOptions = [.transitionFlipFromBottom, .showHideTransitionViews]
    UIView.transition(with: firstView, duration: 0.5, options: transitionOptions, animations: {
        firstView.isHidden = true
    })

    UIView.transition(with: secondView, duration: 0.5, options: transitionOptions, animations: {
        secondView.isHidden = false
    })
}

UIView.animate(withDuration: 1, delay: 0, options: .curveEaseOut, animations: {
    secondView.center = self.view.center
    firstView.center = self.view.center
}, completion: {(_) in
    self.flip(firstView: dummyView, secondView: newGroupView)
})