Taking a snapshot of a UICollectionViewCell

Question

I am making a tvOS app and I want it to look similarly to the Movies app. Therefore I have a UICollectionView. Now my cells are not just simple UIImageViews, but are rather somewhat more complicated.

I still want to have the nice focus visual effect (making the cell image bigger and having the light effect on it when the user swipes the remote). So what I am trying to do is render my cell, then take a snapshot of it and then show this snapshot instead of the cell itself. This is how I do it:

extension UIView {
    var snapshot : UIImage {
        UIGraphicsBeginImageContextWithOptions(bounds.size, true, 0.0)
        drawViewHierarchyInRect(self.bounds, afterScreenUpdates: true)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

...

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = NSBundle.mainBundle().loadNibNamed("ContentCell", owner: self, options: nil)[0] as! ContentCell
    cell.update()
    let cellSnapshot = cell.snapshot

    let snapshotCell = collectionView.dequeueReusableCellWithReuseIdentifier("SnapshotCell", forIndexPath: indexPath) as! SnapshotCell
    snapshotCell.snapshotImageView.image = cellSnapshot
    return snapshotCell
}

However, all this does is show a black cell. Any ideas what might I be doing wrong?

Answer 1

You should look here

In Swift it will be smth like that:

extension UIView {
    var snapshot : UIImage? {
        var image: UIImage? = nil
        UIGraphicsBeginImageContext(bounds.size)
        if let context = UIGraphicsGetCurrentContext() {
            self.layer.renderInContext(context)
            image = UIGraphicsGetImageFromCurrentImageContext()
        }
        UIGraphicsEndImageContext()
        return image
    }
}