Circle scale animation works a bit weird - swift

Question

I am animating my GMSMarker so that it pulse once in couple seconds.
func addWave()
{
// circleView.layer.cornerRadius = size / 2
//Scale
let scaleAnimation = CABasicAnimation(keyPath: "transform.scale")
scaleAnimation.fromValue = 1
scaleAnimation.toValue = zoom
//Opacity
let alphaAnimation = CABasicAnimation(keyPath: "opacity")
alphaAnimation.toValue = 0.0
//Corner radius
// let cornerRadiusAnimation = CABasicAnimation(keyPath: "cornerRadius")
// cornerRadiusAnimation.fromValue = size / 2
// cornerRadiusAnimation.toValue = (size * zoom)/2
//Animation Group
let animations: [CAAnimation] = [scaleAnimation, alphaAnimation]
let animationGroup = CAAnimationGroup()
animationGroup.duration = duration
animationGroup.animations = animations
animationGroup.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
animationGroup.repeatCount = 1
animationGroup.fillMode = kCAFillModeForwards
animationGroup.isRemovedOnCompletion = false
circleView.layer.add(animationGroup, forKey: "group")
}
The result looks like this:
And if I uncomment Corner radius section it looks like this:
So I need an advice.

Answer 1

Based on my observations, I think it must be a issue of wrong path of your CAShapeLayer hence the masking of the circle.
I just wrote a radar animation, I hope it might help you.
let scaleAnimation = CABasicAnimation(keyPath: "transform.scale")
scaleAnimation.fromValue = 0
scaleAnimation.toValue = 1
let alphaAnimation = CABasicAnimation(keyPath: "opacity")
alphaAnimation.fromValue = 1
alphaAnimation.toValue = 0
let animations = CAAnimationGroup()
animations.duration = 0.8
animations.repeatCount = Float.infinity
animations.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
animations.animations = [scaleAnimation, alphaAnimation]
circleView.layer.add(animations, forKey: "animations")
What I did was, I used two CAShapeLayer (one being the orange marker and other is the rader layer at the back of marker). The animations were applied on the radar layer.
radarLayer = CAShapeLayer()
radarLayer.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: self.frame.size.height);
radarLayer.path = UIBezierPath(rect: radarLayer.frame).cgPath
radarLayer.fillColor = UIColor.orange.cgColor
radarLayer.position = CGPoint(x: self.frame.size.width/2, y: self.frame.size.height/2)
radarLayer.cornerRadius = radarLayer.frame.size.width/2
radarLayer.masksToBounds = true
radarLayer.opacity = 0
self.layer.addSublayer(radarLayer)
circleLayer = CAShapeLayer()
circleLayer.frame = CGRect(x: 0, y: 0, width: 16, height: 16);
circleLayer.path = UIBezierPath(rect: circleLayer.frame).cgPath
circleLayer.fillColor = UIColor.orange.cgColor
circleLayer.position = CGPoint(x: self.frame.size.width/2, y: self.frame.size.height/2)
circleLayer.cornerRadius = circleLayer.frame.size.width/2
circleLayer.masksToBounds = true
self.layer.addSublayer(circleLayer)
PS. I'm new to Swift, so enlighten me if I'm wrong somewhere :)
Example : http://i.imgur.com/v2jFWgw.jpg

Answer 2

The following in an excerpt from Google documentation on Markers:
The view behaves as if clipsToBounds is set to YES, regardless of its actual value. You can apply transforms that work outside the bounds, but the object you draw must be within the bounds of the object. All transforms/shifts are monitored and applied. In short: subviews must be contained within the view.
The consequence of that, at least for my case, was exactly the behaviour mentioned in the question: a squared circle animation. The image I wanted to add inside the marker, at the end of the animation, was bigger than the container, so once added to the marker, it was clipped to the bounds of it.
The following is what I did:
public var pulseImageView: UIImageView = {
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 300, height: 300))
imageView.image = PaletteElements.pulseLocation.value
imageView.contentMode = .center
let pulseAnimation = CABasicAnimation(keyPath: "transform.scale.xy")
pulseAnimation.repeatCount = Float.infinity
pulseAnimation.fromValue = 0
pulseAnimation.toValue = 2.0
pulseAnimation.isRemovedOnCompletion = false
let fadeOutAnimation = CABasicAnimation(keyPath: "opacity")
fadeOutAnimation.duration = 2.5
fadeOutAnimation.fromValue = 1.0
fadeOutAnimation.toValue = 0
fadeOutAnimation.repeatCount = Float.infinity
let animationGroup = CAAnimationGroup()
animationGroup.duration = 2.5
animationGroup.animations = [pulseAnimation, fadeOutAnimation]
animationGroup.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeOut)
animationGroup.repeatCount = .greatestFiniteMagnitude
animationGroup.fillMode = CAMediaTimingFillMode.forwards
animationGroup.isRemovedOnCompletion = false
imageView.layer.add(animationGroup, forKey: "pulse")
return imageView
}()
I defined a var inside my helper class so I can retrieve the image whenever I need it. My original image, the pulse image, was 116x116, so I created the imageView as 300x300 with a contentMode = .center, so the small image was in the center and not stretched. I chose 300x300 because my animation scaled up the pulse image until a 2x its initial value (116x2), so I made room for the entire animation to be performed.
Finally I added it to as a Marker to the map:
let pulseMarker = GMSMarker(position: userLocation.coordinate)
pulseMarker.iconView = pulseImageView
pulseMarker.groundAnchor = CGPoint(x: 0.5, y: 0.5)
pulseMarker.map = googleMapView
Hope it can help.