My problem is that I have a custom UIView, which is representing a popup. Inside this view I want to have a slider, which has a label that gets updated every time I drag the slider around. The slider logic works, at least when I'm using it in a ViewController directly, but not with with my custom view. Specifically, the method specified in addTarget doesn't get called at all. I also tried setting the backgroundColor of the slider to something, and it actually showed up, meaning it has a frame. So, what am I missing here? I had a similar problem a lot of times with UIButton, etc. in custom UIView subclasses.
class PriceVoteController: UIView {
var parentView: UIView = UIView()
let slider: UISlider = {
let slider = UISlider()
slider.isContinuous = true
slider.minimumValue = 1
slider.maximumValue = 3
slider.setMinimumTrackImage(#imageLiteral(resourceName: "minimumSliderTrackImage").resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 9, bottom: 0, right: 9)), for: .normal)
slider.setMaximumTrackImage(#imageLiteral(resourceName: "maximumSliderTrackImage").resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 9, bottom: 0, right: 9)), for: .normal)
let sliderThumb = #imageLiteral(resourceName: "sliderThumImage")
slider.setThumbImage(sliderThumb, for: .normal)
slider.addTarget(self, action: #selector(adjustPriceLabel), for: .valueChanged)
slider.setValue(2.0, animated: true)
return slider
}()
let priceLabel: UILabel = {
let label = UILabel()
label.textAlignment = .center
return label
}()
let blackView: UIView = {
let view = UIView()
view.backgroundColor = .black
view.alpha = 0.2
return view
}()
let popUpView: UIView = {
let view = UIView()
view.layer.backgroundColor = UIColor.white.cgColor
view.layer.cornerRadius = 10
return view
}()
@objc fileprivate func adjustPriceLabel() {
print("adjust label")
priceLabel.text = String(format: "%.1f", slider.value)
priceLabelLeftConstraint.constant = getXPositionForSliderValue()
}
fileprivate func getXPositionForSliderValue() -> CGFloat {
guard let currentThumbImage = slider.currentThumbImage else { return 0 }
let sliderRange = slider.frame.size.width - currentThumbImage.size.width;
let sliderOrigin = slider.frame.origin.x + (currentThumbImage.size.width / 2.0);
let sliderValueToPixels = ((CGFloat(slider.value - slider.minimumValue)/CGFloat(slider.maximumValue - slider.minimumValue)) * sliderRange) + sliderOrigin;
return sliderValueToPixels;
}
var priceLabelLeftConstraint: NSLayoutConstraint = NSLayoutConstraint()
override init(frame: CGRect) {
super.init(frame: frame)
self.isUserInteractionEnabled = true
}
fileprivate func setupSlider() {
self.popUpView.addSubview(slider)
slider.anchor(top: self.popUpView.topAnchor, left: self.popUpView.leftAnchor, bottom: nil, right: self.popUpView.rightAnchor, paddingTop: 10, paddingLeft: 50, paddingBottom: 0, paddingRight: 50, width: 0, height: 0)
self.popUpView.addSubview(priceLabel)
priceLabel.text = String(slider.value)
priceLabel.anchor(top: slider.bottomAnchor, left: nil, bottom: nil, right: nil, paddingTop: 10, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
priceLabelLeftConstraint = priceLabel.centerXAnchor.constraint(equalTo: self.popUpView.leftAnchor, constant: getXPositionForSliderValue())
priceLabelLeftConstraint.isActive = true
}
func showOn(view: UIView) {
parentView = view
parentView.addSubview(self.popUpView)
self.popUpView.anchor(top: nil, left: nil, bottom: nil, right: nil, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: view.frame.width - 100, height: 200)
self.popUpView.centerXAnchor.constraint(equalTo: parentView.centerXAnchor).isActive = true
self.popUpView.centerYAnchor.constraint(equalTo: parentView.centerYAnchor).isActive = true
setupSlider()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
I really hope that someone can help me with this, as I've tried to figure this out for the past hours... and no solution :/ As I said, the method gets called when everything is inside a ViewController and its view, but not with the custom UIView.
And by the way, the parentView property is the main view of the viewController, where the custom UIView gets initialized. I initialize it with the empty constructor and then call show() with the ViewController's view.
Thanks for your help! - Robert