/*

    Copyright (C) 2017 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    A `UICollectionViewCell` subclass used to display `DataItem`s within `UICollectionView`s.

*/

import UIKit

class DataItemCollectionViewCell: UICollectionViewCell {

    // MARK: Properties

    static let reuseIdentifier = "DataItemCell"

    @IBOutlet weak var label: UILabel!

    @IBOutlet weak var imageView: UIImageView!

    var representedDataItem: DataItem?

    // MARK: Initialization

    override func awakeFromNib() {

        super.awakeFromNib()

        // These properties are also exposed in Interface Builder.

        imageView.adjustsImageWhenAncestorFocused = true

        imageView.clipsToBounds = false

        label.alpha = 0.0

    }

    // MARK: UICollectionReusableView

    override func prepareForReuse() {

        super.prepareForReuse()

        // Reset the label's alpha value so it's initially hidden.

        label.alpha = 0.0

    }

    // MARK: UIFocusEnvironment

    override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {

        /*

            Update the label's alpha value using the `UIFocusAnimationCoordinator`.

            This will ensure all animations run alongside each other when the focus

            changes.

        */

        coordinator.addCoordinatedAnimations({

            if self.isFocused {

                self.label.alpha = 1.0

            }

            else {

                self.label.alpha = 0.0

            }

        }, completion: nil)

    }

}