Change height and width of view according to scrollview scroll horizontally using auto layout - swift

Question

Container View hierarchy:-
Container View
Scrollview
view left
view center
view right
FloatingBottomView
I need to change height and width constrain of FloatingBottomView according to scrollview scroll horizontally.
Initial Outlet:-
#IBOutlet weak var constantFloatingBottomViewWidth: NSLayoutConstraint! // 300
#IBOutlet weak var constantFloatingBottomViewHeight: NSLayoutConstraint! // 70
override func viewWillAppear(_ animated: Bool) {
self.scrollView.contentOffset.x = self.view.bounds.width
// view center in scrollview
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.x < self.view.bounds.width {
// when scrollview move view center to view left, constantFloatingBottomViewWidth and height goes to down at some point
}
else if scrollView.contentOffset.x > self.view.bounds.width {
// when scrollview move view left to view center, constantFloatingBottomViewWidth & height goes up to same point range while it down and back to original constantFloatingBottomViewWidth and height
}
}
i have tried using this way to get some scale in scrollViewDidScroll method.
scroll quick left to right or vice-versa did not get exactly out-put
let scale = abs(scrollView.contentOffset.x / self.view.bounds.width)
print("scale:=\(scale)")

Answer 1

I think you need to give button animation like this
For this you have nothing to do just add animation to button like follow
call setupButtonanimation in viewDidLoad
func setupButtonAnimation()
{
let animation = CABasicAnimation.init(keyPath: "transform.scale")
animation.fromValue = 1.0
animation.toValue = 0.45
animation.duration = 1.0
//Set the speed of the layer to 0 so it doesn't animate until we tell it to
self.btn1.layer.speed = 0.0;
self.btn1.layer.add(animation, forKey: "transform");
}
func scrollViewDidScroll(_ scrollView: UIScrollView)
{
let screenSize = self.view.bounds.size
if let btn = self.btn1
{
var factor:CGFloat = 1.0
factor = scrollView.contentOffset.x / screenSize.width
if factor > 1
{
factor = 2 - factor
}
print(factor)
//This will change the size
let timeOffset = CFTimeInterval(1-factor)
btn.layer.timeOffset = timeOffset
}
}