How to fit a thumb to custom size switch? - ios

Question

I'm working on the custom UISwitch. I have changed size using this:
self.transform = CGAffineTransform(scaleX: 1.25, y: 1.16).
And now I have one problem, the thumb is still default size.
How can I fit it with uiswitch?
class CustomSwitch:UISwitch {
override init(frame: CGRect) {
super.init(frame: frame)
self.viewDidLoad()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
self.viewDidLoad()
}
func viewDidLoad() {
self.transform = CGAffineTransform(scaleX: 1.25, y: 1.16)
self.setupAppearance()
self.setColors()
self.addTarget(self, action: #selector(toggleState), for: .valueChanged)
}
func setupAppearance() {
self.layer.borderColor = UIColor.HavelockBlue.cgColor
self.layer.borderWidth = 1.0
self.layer.cornerRadius = self.bounds.height / 2
}
func setColors() {
self.backgroundColor = .white
self.subviews.first?.subviews.first?.backgroundColor = .clear
self.onTintColor = .white
self.thumbTintColor = .HavelockBlue
}
#objc func toggleState() {
if self.isOn {
print("Dark mode is on")
} else {
print("Dark mode is off")
}
}
}

Answer 1

Your problem is, you settings constrained width and height for your custom UISwitch, and after then you are trying to transform this object, but what actually happen.
Inside this override init(frame: CGRect) and required init?(coder: NSCoder) methods if you using auto layout you don't have actually final size of your UIView, the size is taken from IB. But you are setting self.layer.cornerRadius = self.bounds.height / 2. If you will print values of frame.size and bounds.size you will see.
Simple solution is to remove constrained sizes from IB and just transform to your desire scale.
Example:
required init?(coder: NSCoder) {
super.init(coder: coder)
changeSwitchSize()
}
override init(frame: CGRect) {
super.init(frame: frame)
changeSwitchSize()
}
private func changeSwitchSize() {
print("Before transform switch frame size: \(frame.size), bounds size: \(bounds.size)")
self.transform = CGAffineTransform(scaleX: 1.25, y: 1.16)
print("After transform switch frame size: \(frame.size), bounds size: \(bounds.size)")
}
/// Before transform switch frame: (51.0, 31.0), (51.0, 31.0)
/// After transform switch frame: (63.75, 35.95999999999998), (51.0, 31.0)
But be aware than CGAffineTransform change view's frame relative to its superview
More about it: https://stackoverflow.com/a/11288488/6057764