UIKit - adding layer effect to button removes image - ios

Question

I have a "fake" check box that I made using UIButton and:
var mCheckState: Bool = false {
didSet {
if mCheckState == true {
self.setImage(checkedImage, for: UIControl.State.normal)
} else {
self.setImage(uncheckedImage, for: UIControl.State.normal)
}
}
}
But when I create this layer style to add shadow/highlight edge:
contentHorizontalAlignment = .left;
contentEdgeInsets = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 0);
setTitleColor(.black, for: UIControl.State.normal)
setTitleColor(UIColor(red: 0.85, green: 0.70, blue: 0.65, alpha: 1.0), for: UIControl.State.highlighted)
layer.backgroundColor = globalColorCG_white_background
layer.shadowColor = CGColor(gray: 1.0, alpha: 1.0)
layer.shadowOpacity = 0.8
layer.shadowRadius = globalButtonRadiusShadow * 0.75
layer.cornerRadius = globalButtonRadiusShadow
layer.shadowOffset = CGSize(width: -6.0,height: -8.0)
layer2 = CALayer(layer: layer)
layer2!.backgroundColor = globalColorCG_white_background
layer2!.shadowColor = CGColor(gray: 0.0, alpha: 1.0)
layer2!.shadowOpacity = 0.1
layer2!.shadowRadius = globalButtonRadiusShadow * 0.5
layer2!.cornerRadius = globalButtonRadiusShadow
layer2!.shadowOffset = CGSize(width: 6.0, height: 8.0)
layer2!.frame = layer.bounds
layer.insertSublayer(layer2!, at: 0)
showsTouchWhenHighlighted = true
...the image no longer renders. What should I add/fix to get the image to render again? :- )
Extra code for info:
let checkedImage = UIImage(systemName: "checkmark.square")! as UIImage
let uncheckedImage = UIImage(systemName: "square")! as UIImage
var mIsCheckBox = false
var mCheckState: Bool = false {
didSet {
if mCheckState == true {
self.setImage(checkedImage, for: UIControl.State.normal)
//self.bringSubviewToFront(checkedImage)
} else {
self.setImage(uncheckedImage, for: UIControl.State.normal)
//self.bringSubviewToFront(uncheckedImage)
}
}
}

Answer 1

You can bring to front your image
class ButtonSubclass: UIButton {
override func awakeFromNib() {
super.awakeFromNib()
/**
Set other button property and layers.
*/
if let imgView = imageView {
self.bringSubviewToFront(imgView)
}
}
}

Answer 2

You need to add your layer2 below the button's ImageView layer.
So change this line:
layer.insertSublayer(layer2!, at: 0)
To this:
layer.insertSublayer(layer2!, below: imageView!.layer)
You may want to check the button's imageView isn't nil and in cases where it is just add as you have already:
if let imageViewLayer = imageView?.layer {
layer.insertSublayer(layer2!, below: imageViewLayer)
} else {
layer.insertSublayer(layer2!, at: 0)
}