Detect if a UICollectionViewCell is being displayed

Question

I have set a UICollectionView to 'Paging Enabled'. I want to be informed when a UICollectionViewCell becomes active.

It seems like the collectionView:didSelectItemAtIndexPath: of the UICollectionViewController cannot achieve this effect: It only fires when a user explicitly select a cell, not when the cell is swiped to the front.

Each cell has a view controller associated with it. I probably can use viewDidLoad to as a proxy of this event. But it does not sound like a clean solution.

Answer 1

You can use collectionView:didEndDisplayingCell:forItemAtIndexPath: to detect that something changed and visibleCells to know what now on screen