How to trigger an function of an UICollectionViewCell inside an UICollectionViewController? - swift

Question

I would like to trigger the animation3() function (which is a function inside PageCell() which is a UICollectionViewCell) inside the BreathingSwpipingController which is a UICollectionViewController.
class BreathingSwipingController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
var pageCell: PageCell?
override func viewDidLoad() {
super.viewDidLoad()
collectionView.backgroundColor = .white
collectionView.register(PageCell.self, forCellWithReuseIdentifier: "cellId")
collectionView.isPagingEnabled = true
setupStartStopButton()
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
pageCell = (collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath) as? PageCell)!
return pageCell!
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.frame.width, height: collectionView.frame.height)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
#objc func startStopTapped() {
pageCell!.animation3()
}
}

Answer 1

Make PageCell a delegate of BreathingSwipingController by making a protocol
protocol BreathingSwipingDelegate: class {
func doSth()
}
now inside UICollectionViewController define a weak var delegate: BreathingSwipingDelegate?
then head to PageCell file and conform to that protocol
class PageCell: BreathingSwipingDelegate .... {
func doSth() {
animation3()
}
var mController = BreathingSwipingController()
override init(style: .....) {
mController.delegate = self
.
.
.
.
}
}
now in BreathingSwipingController make the following
#objc func startStopTapped() {
delegate?.doSth()
}