Swift 设置子类 UIButton ButtonType

Question

I have a simple subclass of UIButton

class IconButton: UIButton {

    init(type: FontAwesomeStyle, icon: FontAwesome, color: UIColor = .black, size: CGFloat = 20) {
        super.init(frame: CGRect.zero)

        let iconAsText = String.fontAwesomeIcon(name: icon)
        let iconText = NSMutableAttributedString(string: iconAsText, attributes: [
            NSAttributedString.Key.font: UIFont.fontAwesome(ofSize: size, style: type)
        ])

        setAttributedTitle(iconText, for: .normal)
        setTitleColor(color, for: .normal)

    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

The problem I am having is that I would like the button to have the behavior that system buttons have. Specifically when you press and hold the button, it changes color.

let button = UIButton(type: .system)

Since buttonType is a get only property of UIButton and UIButton.init(type: UIButton.ButtonType) is a convenience initailizer, I am not sure how to implement this a subclass.

Answer 1

Still not sure if its possible to replicate the .system button type in a subclass, but the solution for getting the behavior I wanted was the following:

class IconButton: UIButton {

    override var isHighlighted: Bool {
        willSet(newVal) {
           if newVal != isHighlighted {
               // newVal is true when the button is being held down

           }
        }
    }

    // Rest of class...
}