在init的闭包内部创建的地址实例

Question

I have a Class ControlPanel that needs to make some adjustments to its UI Elements during initialization. I want to pass those adjustments as a closure in it's init() . But how do I correctly reference self ? When doing this...

let cornerRadius = ControlPanel(title: "Corner Radius",
                                        layout: .oneSlider,
                                        sliderRange: (0.0, 30.0),
                                        setup: { self.someProperty = 5 }
        )

...Swift of course assumes self refers to the class in which I am calling this initializer. Which is totally unrelated. Is there any syntax like theSelfWhenThisClosureIsBeingExecuted ?

My ControlPanel init is defined like this:

init(title: String, layout: PanelControlLayoutType, sliderRange: (min: Float, max: Float), editClosure1of1: ((Float) -> ())?, setup: () -> ()) {
    super.init(frame: CGRect())
    commonInit(title: title)
    guard layout == .oneSlider else { fatalError("Wrong paneltype") }
    let singleSlider = UISlider()
    slider1?[0] = singleSlider
    singleSlider.minimumValue = sliderRange.min
    singleSlider.maximumValue = sliderRange.max
    self.addSubview(singleSlider)
    self.editClosure1of1 = editClosure1of1
    singleSlider.translatesAutoresizingMaskIntoConstraints = false
    singleSlider.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 50.0).isActive = true
    singleSlider.rightAnchor.constraint(equalTo: self.rightAnchor, constant: -50.0).isActive = true
    singleSlider.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -32.0).isActive = true
    singleSlider.tag = 0
    singleSlider.addTarget(self, action: #selector(self.sliderChanged(_:withEvent:)), for: .valueChanged)
}

Answer 1

You could declare setup as a closure which takes the just created instance as parameter. Example:

class ControlPanel: UIView {

    let title: String
    var someProperty: Int = 0

    init(title: String, setup: ((ControlPanel) -> Void)? = nil) {
        self.title = title
        super.init(frame: CGRect())

        if let setup = setup {
            setup(self)
        }
    }

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

This can then be called as

let panel = ControlPanel(title: "title") {
    $0.someProperty = 5
}

However, the closure can only be called when the instance is fully initialized, which means that someProperty needs to be a variable, and must be assigned an initial value. So there is not much advantage over doing the custom setup after creating the instance:

let panel = ControlPanel(title: "title")
panel.someProperty = 5