Replace line that causes segueing errors

[lurein]

Replaced the range-format visibleIndices line with a stride-format as it was causing crashes when returning from segues as minVisibleIndex could become greater than maxVisibleIndex

[filletofish]

Thank you for contribution! 👍

[filletofish]

@lurein Have you discovered why minVisibleIndex could become greater than maxVisibleIndex?
Can you explain how to reproduce it?

[lurein]

@filletofish For me it occurred when I implemented a system where tapping on cards would segue to a new viewcontroller. When dismissing the Show viewcontrollers, the immediate order of the cards was disturbed as the dismissed card (which in that moment is the maxVisibleIndex) is then placed before the card that was in that moment the minVisibleIndex. Creating a similar segue system should reproduce it. It's important to note that the order of cards was pulled from a database and so it would be a different order everytime

[filletofish]

@lurein I have implemented this segue, to show viewcontroller after selecting item:

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    selectedColor = collectionView.cellForItem(at: indexPath)?.backgroundColor
    performSegue(withIdentifier: "someSegue", sender: self)
  }

I have not received any errors. Maybe it is on your side, something like not calling reloadData in correct moment?

I have no idea how can dismissing of ViewController disturb wrong calculation of min / max indices. The only thing that can go wrong in calculation of min / max indices is having wrong contentOffset.x:

let minVisibleIndex = max(Int(collectionView.contentOffset.x) / Int(collectionView.bounds.width), 0)
let maxVisibleIndex = min(minVisibleIndex + maximumVisibleItems, totalItemsCount)

How does it happen in your case?