UIActivityIndicatorView disappears in CollectionView Footer

Question

I have a collectionView with only 1 section in my app which download data from API. I have a pagination and I am trying to add a loading footer in my collectionView. The header appears normally. I have in this footer cell an UIActivityIndicatorView and a UILabel. When the first at a limit is triggered, the 2 elements are present in the cell but when the second limit is triggered, the UIActivityIndicatorView is absent.

Have you an idea for that.

The code of the cell (BaseCell is just a class to avoid tapping the init and required init each time):

class loadingCell: BaseCell {

    override func setupViews() {
        super.setupViews()

        backgroundColor = .yellow

        let activity = UIActivityIndicatorView()
        activity.backgroundColor = .red
        activity.startAnimating()
        activity.frame = CGRect(x: 10, y: 20, width: 20, height: 20)
        let label = UILabel()
        label.text = "hello"
        label.frame = CGRect(x: 100, y: 20, width: 40, height: 20)
        label.backgroundColor = .green


        addSubview(activity)
        addSubview(label)

    }

}

The collection delegate methods :

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
     return CGSize(width: SCREENW, height: 50)
}

func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {

    if kind == UICollectionElementKindSectionFooter {
        let loadingFooterView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionFooter, withReuseIdentifier: loadingCell, for: indexPath)
        return loadingFooterView
    }

    return UICollectionReusableView()
}

The cell is well registered.

What happens when first limit is triggered:

And with the second:

UIActivityIndicatorView has property called `hidesWhenStopped`. Because of dequeuing headers, it uses previous state if you did not configure it properly. You can override `prepareForReuse` method, where you will start animation. — Maksym Musiienko, Nov 11 '17 at 17:43
Thanks @MaksymMusiienko, I have answer my post base on your comment. Can you confirm that it was what you meant ? — Florian Ldt, Nov 12 '17 at 08:58

score 0 · Accepted Answer · answered Nov 12 '17 at 08:56

Based on @MaksymMusiienko comment, I have tried this which do the job to reset the animation of the spinner.

class loadingCell: BaseCell {

    let activitySpinner: UIActivityIndicatorView = {
       let spinner = UIActivityIndicatorView()
        spinner.backgroundColor = .red
        spinner.startAnimating()
        spinner.frame = CGRect(x: 10, y: 20, width: 20, height: 20)
        return spinner

    }()

    override func setupViews() {
        super.setupViews()

        backgroundColor = .yellow

        let label = UILabel()
        label.text = "hello"
        label.frame = CGRect(x: 100, y: 20, width: 40, height: 20)
        label.backgroundColor = .green


        addSubview(activitySpinner)
        addSubview(label)

    }

    override func prepareForReuse() {
        super.prepareForReuse()
        activitySpinner.startAnimating()
    }
}

Yes. If you are showing this cell only in case, when you are loading elements:) Did it work for you? — Maksym Musiienko, Nov 13 '17 at 08:50

UIActivityIndicatorView disappears in CollectionView Footer

1 Answers1