Is it possible to implement touch event handling on a CALayer?

No, it is not possible to directly handle touch events at the CALayer level, as CALayer is only responsible for rendering and animation, not for handling user input.

Touch event handling occurs at the UIView level or its subclasses, which contain a CALayer. To respond to touches, you need to override event handling methods in UIView or use UITapGestureRecognizer and other gesture recognizers.

Example of touch handling in UIView:

class TouchView: UIView {
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesBegan(touches, with: event)
        print("Touch started")
    }
}

Thus, CALayer is not intended for event handling, but serves for visual presentation.