MKMapView doesn't adhere to animation delay - ios

Question

I'm fiddling with my MKMapView in Playground, and I'm having trouble animating it's frame.size.height. Here's my Playground code:
let vc = UIViewController()
vc.view.backgroundColor = UIColor.whiteColor()
XCPlaygroundPage.currentPage.liveView = vc
let map = MKMapView(frame: vc.view.frame)
map.backgroundColor = UIColor.redColor()
map.autoresizesSubviews = false
vc.view.addSubview(map)
UIView.animateWithDuration(2.0, delay: 1.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 1.0, options: .CurveEaseInOut, animations: {
map.frame.size.height = 200
}, completion: nil)
You can tell when the actual animation is occurring by observing the map's red background color. The visible map's height decreases before the MKMapView's height. Setting autoresizesSubviews = false doesn't seem to do anything. So why does it seem as if there are two distinct animations?
UPDATE In my Playground, I removed all my MKMapView subviews, and the _MKMapContentView, one of the map's two subviews (the other being the "Legal" MKAttributionLabel), was removed, rendering the MKMapView with just it's red background. So the _MKMapContentView is being resized as a subview, but calling map.autoresizesSubviews = false isn't doing the trick. What gives?

Answer 1

This is a bit of a hack, if you will. I tried animating the map's height using animateWithDuration:delay:usingSpringWithDamping and a nonzero delay. My problem was that the _MKMapContentView wouldn't adhere to the delay, which is what explained the distinct animations.
So, with a little help from #Matt's famous delay solution, I scrapped my function delay and put the entire method in a delay block, so that any (sub)views would animate concurrently.
delay(3.5) {
UIView.animateWithDuration(1.0, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 1.0, options: .CurveEaseInOut, animations: {
map.frame.size.height -= 200
}, completion: nil)
}
func delay(delay:Double, closure:()->()) {
dispatch_after(
dispatch_time(
DISPATCH_TIME_NOW,
Int64(delay * Double(NSEC_PER_SEC))
),
dispatch_get_main_queue(), closure)
}
Bit of a workaround, but it works. Still eager to learn why map's subviews didn't adhere to the function delay, if anyone has an idea.

Answer 2

I think you maybe to user this to avoid:
map.backgroundColor = UIColor.whiteColor()
vc.view.addSubview(map)
UIView.animateWithDuration(2.0, delay: 1.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 1.0, options: .CurveEaseInOut, animations: {
map.frame.size.height = 200
}, completion:
map.backgroundColor = UIColor.redColor()
)