IBDesignable properties not updating during runtime - ios

Question

I have created a custom segmented control using this video (https://www.youtube.com/watch?v=xGdRCUrSu94&t=2502s) . I want to be able to change the string values displayed inside the custom segmented control (commaSeperatedButtonTitles) during runtime from 1,2,3,4 to 5,6,7,8 but for some reason the view is not updating the values. The values seem to be able to be changed in viewDidLoad but not inside action events which is what I need.
import UIKit
#IBDesignable
class CustomSegmentedControl: UIControl {
var buttons = [UIButton]()
var selector: UIView!
var selectedSegmentIndex = 0
#IBInspectable
var borderWidth: CGFloat = 0 {
didSet{
layer.borderWidth = borderWidth
}
}
#IBInspectable
var borderColor: UIColor = UIColor.gray {
didSet{
layer.borderColor = borderColor.cgColor
}
}
#IBInspectable
var commaSeperatedButtonTitles: String = "" {
didSet{
}
}
#IBInspectable
var textColor: UIColor = .lightGray {
didSet{
}
}
#IBInspectable
var selectorColor: UIColor = .blue {
didSet{
}
}
#IBInspectable
var selectorTextColor: UIColor = .white {
didSet{
}
}
func updateView(){
buttons.removeAll()
subviews.forEach { (view) in
view.removeFromSuperview()
}
var buttonTitles = commaSeperatedButtonTitles.components(separatedBy: ",")
for buttonTitle in buttonTitles {
let button = UIButton(type: .system)
button.setTitle(buttonTitle, for: .normal)
button.setTitleColor(textColor, for: .normal)
button.addTarget(self, action: #selector(buttonTapped(button:)), for: .touchUpInside)
buttons.append(button)
}
buttons[0].setTitleColor(selectorTextColor, for: .normal)
let selectorWidth = (frame.width / CGFloat(buttonTitles.count))
selector = UIView(frame: CGRect(x: 0, y: 0, width: selectorWidth, height: frame.height))
selector.layer.cornerRadius = (frame.height / 2)
selector.backgroundColor = selectorColor
addSubview(selector)
let sv = UIStackView(arrangedSubviews: buttons)
sv.axis = .horizontal
sv.alignment = .fill
sv.distribution = .fillEqually
addSubview(sv)
sv.translatesAutoresizingMaskIntoConstraints = false
sv.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
sv.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
sv.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
sv.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
self.setNeedsDisplay()
}
override func draw(_ rect: CGRect) {
// Drawing code
layer.cornerRadius = (frame.height / 2)
//updateView()
}
override func layoutSubviews() {
updateView()
}
func buttonTapped(button: UIButton){
for (buttonIndex, btn) in buttons.enumerated() {
btn.setTitleColor(textColor, for: .normal)
if btn == button{
selectedSegmentIndex = buttonIndex
let selectorStartPosition = (frame.width / CGFloat(buttons.count) * CGFloat(buttonIndex))
UIView.animate(withDuration: 0.3, animations: {
self.selector.frame.origin.x = selectorStartPosition
})
btn.setTitleColor(selectorTextColor, for: .normal)
}
}
sendActions(for: .valueChanged)
}
}
Code in View Controller inside action event:
customSegment.commaSeperatedButtonTitles = "5,6,7,8"

Answer 1

It appears to me that updateView() method is not being called after you set the commaSeperatedButtonTitles property. Try calling it after the property is set:
#IBInspectable
var commaSeperatedButtonTitles: String = "" {
didSet {
self.updateView()
}
}
Another point worth mentioning: it's probably unnecessary to call updateView() every time on layoutSubviews() as it recreates all the buttons for your custom segmented control.