I have a UICollectionView with horizontally scrolling sections.
In the cell I have a UIButton.
I need to cancel the touches when the user swipes horizontally but it does not work.
touchesShouldCancel(in:) is only called when swiping vertically over the UIButton, not horizontally.
Is there a way to make it work?
Sample code below
import UIKit
class ConferenceVideoSessionsViewController: UIViewController {
let videosController = ConferenceVideoController()
var collectionView: UICollectionView! = nil
var dataSource: UICollectionViewDiffableDataSource
<ConferenceVideoController.VideoCollection, ConferenceVideoController.Video>! = nil
var currentSnapshot: NSDiffableDataSourceSnapshot
<ConferenceVideoController.VideoCollection, ConferenceVideoController.Video>! = nil
static let titleElementKind = "title-element-kind"
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.title = "Conference Videos"
configureHierarchy()
configureDataSource()
}
}
extension ConferenceVideoSessionsViewController {
func createLayout() -> UICollectionViewLayout {
let sectionProvider = { (sectionIndex: Int,
layoutEnvironment: NSCollectionLayoutEnvironment) -> NSCollectionLayoutSection? in
let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
heightDimension: .fractionalHeight(1.0))
let item = NSCollectionLayoutItem(layoutSize: itemSize)
// if we have the space, adapt and go 2-up + peeking 3rd item
let groupFractionalWidth = CGFloat(layoutEnvironment.container.effectiveContentSize.width > 500 ?
0.425 : 0.85)
let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(groupFractionalWidth),
heightDimension: .absolute(200))
let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitems: [item])
let section = NSCollectionLayoutSection(group: group)
section.orthogonalScrollingBehavior = .continuous
section.interGroupSpacing = 20
section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 20, bottom: 0, trailing: 20)
return section
}
let config = UICollectionViewCompositionalLayoutConfiguration()
config.interSectionSpacing = 20
let layout = UICollectionViewCompositionalLayout(
sectionProvider: sectionProvider, configuration: config)
return layout
}
}
extension ConferenceVideoSessionsViewController {
func configureHierarchy() {
collectionView = MyUICollectionView(frame: .zero, collectionViewLayout: createLayout())
collectionView.translatesAutoresizingMaskIntoConstraints = false
collectionView.backgroundColor = .systemBackground
view.addSubview(collectionView)
NSLayoutConstraint.activate([
collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
collectionView.topAnchor.constraint(equalTo: view.topAnchor),
collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
])
collectionView.canCancelContentTouches = true
}
func configureDataSource() {
let cellRegistration = UICollectionView.CellRegistration
<ConferenceVideoCell, ConferenceVideoController.Video> { (cell, indexPath, video) in
// Populate the cell with our item description.
cell.buttonView.setTitle("Push, hold and swipe", for: .normal)
cell.titleLabel.text = video.title
}
dataSource = UICollectionViewDiffableDataSource
<ConferenceVideoController.VideoCollection, ConferenceVideoController.Video>(collectionView: collectionView) {
(collectionView: UICollectionView, indexPath: IndexPath, video: ConferenceVideoController.Video) -> UICollectionViewCell? in
// Return the cell.
return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: video)
}
currentSnapshot = NSDiffableDataSourceSnapshot
<ConferenceVideoController.VideoCollection, ConferenceVideoController.Video>()
videosController.collections.forEach {
let collection = $0
currentSnapshot.appendSections([collection])
currentSnapshot.appendItems(collection.videos)
}
dataSource.apply(currentSnapshot, animatingDifferences: false)
}
}
class MyUICollectionView: UICollectionView {
override func touchesShouldCancel(in view: UIView) -> Bool {
print("AH: touchesShouldCancel view \(view.description)")
if view is MyUIButton {
return true
}
return false
}
}
final class MyUIButton: UIButton {
}
class ConferenceVideoCell: UICollectionViewCell {
static let reuseIdentifier = "video-cell-reuse-identifier"
let buttonView = MyUIButton()
let titleLabel = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
configure()
}
required init?(coder: NSCoder) {
fatalError()
}
}
extension ConferenceVideoCell {
func configure() {
buttonView.translatesAutoresizingMaskIntoConstraints = false
titleLabel.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(buttonView)
contentView.addSubview(titleLabel)
titleLabel.font = UIFont.preferredFont(forTextStyle: .caption1)
titleLabel.adjustsFontForContentSizeCategory = true
buttonView.layer.borderColor = UIColor.black.cgColor
buttonView.layer.borderWidth = 1
buttonView.layer.cornerRadius = 4
buttonView.backgroundColor = UIColor.systemPink
let spacing = CGFloat(10)
NSLayoutConstraint.activate([
buttonView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
buttonView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
buttonView.topAnchor.constraint(equalTo: contentView.topAnchor),
titleLabel.topAnchor.constraint(equalTo: buttonView.bottomAnchor, constant: spacing),
titleLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
titleLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
titleLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor)
])
}
}
