3D Touch: registerForPreviewing in UICollectionViewCell

Here the scenario is, UICollectionView is in UITableViewCell and UITableView is on UIViewController, now I have to use UILongPressGestureRecognizerif 3D Touch is not available I need to register it in UICollectionView Cell, UILongPressGestureRecognizer is working perfectly, but I'm not able to register registerForPreviewing in the cell for 3D Touch. What is the way to register this in cell.

Any help will be appreciated.

Thanks

3D Touch can register only on UIViewController or instance of UIViewController class

Now, you have to register your tableView with 3D Touch. The only problem is getting selected UICollectionViewCell which is in UITableViewCell.

You can get that in UIViewControllerPreviewingDelegate delegate methods

func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {

    //Get indexPath for selected tableViewCell using location
    guard let tableViewIndexPath = tableView.indexPathForRow(at: location) else {
        return nil
    }

    //Get selected tableViewCell
    //NestedCell is UITableViewCell
    guard let tableViewCell = tableView.cellForRow(at: tableViewIndexPath) as? NestedCell else {
        return nil
    }

    //CollectionView which is in every tableViewCell
    let collectionView = tableViewCell.collectionView

    //Get the location of collectionView
    let collectionViewLocation = tableView.convert(location, to: collectionView)

    //Get indexPath of selected collectionViewCell
    guard let collectionViewIndexPath = collectionView.indexPathForItem(at: collectionViewLocation) else {
        return nil
    }

    //Finally, you get selected collectionViewCell
    guard let collectionViewCell = tableViewCell.collectionView.cellForItem(at: collectionViewIndexPath) else {
        return nil
    }

    let preview = PreviewVC()
    preview.view.backgroundColor = collectionViewCell.backgroundColor
    preview.preferredContentSize = CGSize(width: 0.0, height: 600)

    //Modify CGRect/frame for selected collectionview cell
    var sourceRect = collectionViewCell.frame
    sourceRect.origin.x = sourceRect.origin.x - collectionView.contentOffset.x

    let y = tableViewCell.frame.origin.y + collectionViewCell.frame.origin.y
    sourceRect.origin.y = y
    previewingContext.sourceRect = sourceRect
    return preview

}

output: