How to add constraints to a collection view cell once the cell is selected? - ios

Question

I am trying to create a feature programmatically so that when a user selects a cell in the collection view the app keeps a count of the image selected and adds it as an overlay. I am also wanting to add the video duration to the bottom of the image if the selection is a video. I know my problem is in my constraints. You can see in the image example below that I am trying to add the count to the top left of the collection view cell, but also when the user deselects a cell the count adjusts so for example if the number 2 in the image below was deselected the number 3 would become 2. For the most part I think I have the code working but I cannot get the constraints to work. With the current configuration I am getting an error (see below) but I do not even know where to begin with this problem.
"Unable to activate constraint with anchors because they have
no common ancestor. Does the constraint or its anchors reference
items in different view hierarchies? That's illegal."
CollectionView:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if let cell = collectionView.cellForItem(at: indexPath) as? TestCVCell {
cell.commonInit()
}
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
if let cell = collectionView.cellForItem(at: indexPath) as? TestCVCell {
//Not sure what to put here
}
}
Overlay
class CustomAssetCellOverlay: UIView {
let countSize = CGSize(width: 40, height: 40)
lazy var circleView: UIView = {
let view = UIView()
view.backgroundColor = .black
view.layer.cornerRadius = self.countSize.width / 2
view.alpha = 0.4
return view
}()
let countLabel: UILabel = {
let label = UILabel()
let font = UIFont.preferredFont(forTextStyle: .headline)
label.font = UIFont.systemFont(ofSize: font.pointSize, weight: UIFont.Weight.bold)
label.textAlignment = .center
label.textColor = .white
label.adjustsFontSizeToFitWidth = true
return label
}()
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
private func commonInit() {
addSubview(circleView)
addSubview(countLabel)
//***** START - UPDATED BASED ON SUGGESTION IN COMMENTS******
countLabel.translatesAutoresizingMaskIntoConstraints = false
//***** END - UPDATED BASED ON SUGGESTION IN COMMENTS******
countLabel.centerXAnchor.constraint(equalTo: circleView.centerXAnchor).isActive = true
countLabel.centerYAnchor.constraint(equalTo: circleView.centerYAnchor).isActive = true
}
}
Collection View Cell
var img = UIImageView()
var overlayView = UIView()
var asset: PHAsset? {
didSet {}
}
var isVideo: Bool = false {
didSet {
durationLabel.isHidden = !isVideo
}
}
override var isSelected: Bool {
didSet { overlay.isHidden = !isSelected }
}
var imageView: UIImageView = {
let view = UIImageView()
view.clipsToBounds = true
view.contentMode = .scaleAspectFill
view.backgroundColor = UIColor.gray
return view
}()
var count: Int = 0 {
didSet { overlay.countLabel.text = "\(count)" }
}
var duration: TimeInterval = 0 {
didSet {
let hour = Int(duration / 3600)
let min = Int((duration / 60).truncatingRemainder(dividingBy: 60))
let sec = Int(duration.truncatingRemainder(dividingBy: 60))
var durationString = hour > 0 ? "\(hour)" : ""
durationString.append(min > 0 ? "\(min):" : ":")
durationString.append(String(format: "%02d", sec))
durationLabel.text = durationString
}
}
let overlay: CustomAssetCellOverlay = {
let view = CustomAssetCellOverlay()
view.isHidden = true
return view
}()
let durationLabel: UILabel = {
let label = UILabel()
label.preferredMaxLayoutWidth = 80
label.backgroundColor = .gray
label.textColor = .white
label.textAlignment = .right
label.font = UIFont.boldSystemFont(ofSize: 20)
return label
}()
func commonInit() {
addSubview(imageView)
imageView.addSubview(overlay)
imageView.addSubview(durationLabel)
imageView.translatesAutoresizingMaskIntoConstraints = false
//***** START - UPDATED BASED ON SUGGESTION IN COMMENTS******
overlay.translatesAutoresizingMaskIntoConstraints = false
overlayView.translatesAutoresizingMaskIntoConstraints = false
//***** END - UPDATED BASED ON SUGGESTION IN COMMENTS******
NSLayoutConstraint.activate([
overlay.topAnchor.constraint(equalTo: imageView.topAnchor),
overlay.bottomAnchor.constraint(equalTo: imageView.bottomAnchor),
overlay.leftAnchor.constraint(equalTo: imageView.leftAnchor),
overlay.rightAnchor.constraint(equalTo: imageView.rightAnchor),
overlayView.centerXAnchor.constraint(equalTo: overlay.centerXAnchor),
overlayView.centerYAnchor.constraint(equalTo: overlay.centerYAnchor),
overlayView.widthAnchor.constraint(equalToConstant: 80.0),
overlayView.heightAnchor.constraint(equalToConstant: 80.0),
]
)
}
//Some other stuff