CollectionView Auto Scroll - ios

So I have some code that I am using to auto scroll a collectionView and it is giving me lots of problems. It works based off of a timer that calls a certain function every 3.5 seconds to scroll to a certain item in the collectionView. The code is included belwo
import UIKit
class HomeFeedCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout, UIScrollViewDelegate {
var homeFeedController: HomeFeedController?
let emptyView = UIView()
//Timer user for call autoscroller of top collection view
private var timer:Timer?
var scrollTimer = Timer()
private let cellId = "cellId"
var featuredEvents: [Event]?{
didSet {
homeFeedCollectionView.reloadData()
}
}
var titles: String? {
didSet {
guard let titles = titles else {
return
}
// let attributedText = NSMutableAttributedString(string: titles, attributes: [NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 100)])
sectionNameLabel.text = titles
// sectionNameLabel.attributedText = attributedText
}
}
override init(frame: CGRect) {
super.init(frame: frame)
self.setTimer()
setupViews()
}
func setTimer(){
//auto scroll method to call every 2.5 seconds interval
self.timer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(self.startTimer(theTimer:)), userInfo: nil, repeats: true)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let sectionNameLabel : UILabel = {
let sectionNameLabel = UILabel()
sectionNameLabel.font = UIFont(name:"HelveticaNeue-CondensedBlack", size: 36.0)
return sectionNameLabel
}()
lazy var emptyLabel: UILabel = {
let emptyLabel = UILabel()
emptyLabel.text = "Sorry We Currently Have No Events, \n In This Category Near You"
emptyLabel.font = UIFont(name: "Avenir", size: 14)
emptyLabel.numberOfLines = 0
emptyLabel.textAlignment = .center
return emptyLabel
}()
lazy var iconImageView: UIImageView = {
let imageView = UIImageView()
imageView.contentMode = .scaleAspectFit
return imageView
}()
let homeFeedCollectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .clear
return cv
}()
#objc func setupViews(){
backgroundColor = .clear
addSubview(homeFeedCollectionView)
addSubview(sectionNameLabel)
sectionNameLabel.anchor(top: topAnchor, left: leftAnchor, bottom: nil, right: nil, paddingTop: 2, paddingLeft: 4, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
homeFeedCollectionView.anchor(top: sectionNameLabel.bottomAnchor, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor, paddingTop: 4, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
homeFeedCollectionView.delegate = self
homeFeedCollectionView.dataSource = self
homeFeedCollectionView.showsHorizontalScrollIndicator = false
homeFeedCollectionView.register(HomeFeedEventCell.self, forCellWithReuseIdentifier: cellId)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
guard let currentEventCount = featuredEvents?.count else{
return 0
}
if currentEventCount == 0 {
print("no events")
setupEmptyDataSet()
}else{
emptyView.removeFromSuperview()
}
return currentEventCount
}
#objc func setupEmptyDataSet(){
self.addSubview(emptyView)
emptyView.backgroundColor = .clear
emptyView.snp.makeConstraints { (make) in
make.edges.equalTo(self)
}
emptyView.addSubview(iconImageView)
iconImageView.image = UIImage(named: "icons8-face-100")
iconImageView.snp.makeConstraints { (make) in
make.center.equalTo(emptyView)
}
emptyView.addSubview(emptyLabel)
emptyLabel.snp.makeConstraints { (make) in
make.bottom.equalTo(iconImageView.snp.bottom).offset(30)
make.left.right.equalTo(emptyView)
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 20, left: 5, bottom: 20, right: 5)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width - 40, height: frame.height - 40)
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let eventDetails = EventDetailViewController()
eventDetails.currentEvent = featuredEvents?[indexPath.item]
homeFeedController?.navigationController?.pushViewController(eventDetails, animated: true)
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! HomeFeedEventCell
cell.event = featuredEvents?[indexPath.item]
var rowIndex = indexPath.row
let numberOfRecords = (featuredEvents?.count)! - 1
if rowIndex < numberOfRecords {
rowIndex = rowIndex + 1
}else{
rowIndex = 0
}
scrollTimer = Timer.scheduledTimer(timeInterval: 3.5, target: self, selector: #selector(self.startTimer(theTimer:)), userInfo: rowIndex, repeats: true)
return cell
}
#objc func startTimer(theTimer: Timer){
UIView.animate(withDuration: 1.0, delay: 0, options: .curveEaseOut, animations: {
if let currentIndexPath = self.homeFeedCollectionView.indexPathsForVisibleItems.last{
//Check visible cell is last cell of top collection view then set first index as visible
if currentIndexPath.item == self.homeFeedCollectionView.numberOfItems(inSection: 0)-1{
let nextIndexPath = NSIndexPath(item: 0, section: 0)
//top collection view scroller in first item
self.homeFeedCollectionView.scrollToItem(at: nextIndexPath as IndexPath, at: .right, animated: false)
}else{
//create next index path from current index path of the top collection view
let nextIndexPath = NSIndexPath(item: currentIndexPath.item + 1, section: 0)
//top collection view scroller to next item
self.homeFeedCollectionView.scrollToItem(at: nextIndexPath as IndexPath, at: .left, animated: true)
}
}
}) { (finished) in
if finished {
print("done")
}
}
}
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
self.homeFeedCollectionView.scrollToNearestVisibleCollectionViewCell()
}
func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
if !decelerate {
self.homeFeedCollectionView.scrollToNearestVisibleCollectionViewCell()
}
}
}
Im not really sure what I am doing wrong, to be honest. But my problems with this approach are
When you I first enter the collectionView it goes straight to the third item
It sometimes scrolls to a certain item may be the first or the third and then it just gets stuck there and stops moving. It tried to move but it just keeps getting stuck.

You have a viewController for the view that shows up what you want and contains collectionView. This class should implement UICollectionViewDataSource and UICollectionViewDelegate:
class viewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource
in this class you should implement the numberOfItemsInSection and cellForItemAt methods.
and you need another class for cells in the collectionView:
class customCell: UICollectionViewCell
in this class you could define IBOutlets or what ever you want related to each cell NOT collectionView
and in last you should fire the timer in viewDidLoad (or viewDidAppear) instead of cellForItemAt delegate,
that func calls for each row then you start timers as number of cells that your collectionView has.
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
scrollTimer = Timer.scheduledTimer(timeInterval: 3.5, target: self, selector: #selector(self.startTimer(theTimer:)), userInfo: rowIndex, repeats: true)
}

You can use this pod https://cocoapods.org/pods/AutoScrollCollectionView
https://github.com/mohankrishnameruva/AutoScrollCollectionView
Subclass your collection view from 'AutoScrollCollectionView' in storyboard and
whenever you want to start scroll call this method
on collectionView startAutoScrolling(withTimeInterval: TimeInterval(exactly: 2.0)!)

Related

Implementing search function in UICollectionView in a UICollectionViewCell

I want to implement a search function in UICollectionView in a UICollectionViewCell.
What i'm trying to achieve is a swipe-able pages with search bar.
Previously i achieved multiple pages with a search bar but not able to swipe and to match with my Android application i need to make it swipe-able.
This is the tutorial i followed on how to make it swipe-able
https://www.letsbuildthatapp.com/course_video?id=75
To make this sound less confusing, the main UICollectionView let's call it MainFrame and the MainFrame stores the two UICollectionViewCell which contains their own UICollectionView let's call it ChildFrame.
So i'm able to parse search text from MainFrame to the ChildFrame and filter the data array in the ChildFrame. Checking it on the console log, everything is working as intended. The filtered result is correct. But my ChildFrame is not updating to the latest data array. Here's the code below.
Here's the code for ChildFrame
class ChildFrameCell1: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
var dataArray = [CustomObject]()
var filteredData = [CustomObject]()
var isFiltering: Bool = false
var mainFrame: MainFrame?
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 4, left: 0, bottom: 0, right: 0)
layout.minimumInteritemSpacing = 0.0
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .white
cv.dataSource = self
cv.delegate = self
return cv
}()
override init(frame: CGRect) {
super.init(frame: frame)
populateCollectionView()
collectionView.register(CustomCell.self, forCellWithReuseIdentifier: cellId)
addSubview(collectionView)
collectionView.anchor(top: self.topAnchor, left: self.leftAnchor, bottom: self.bottomAnchor, right: self.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func searchTypeAndText(type: String, text: String, filtering: Bool) {
isFiltering = filtering
filteredData = dataArray.filter({( object : CustomObject) -> Bool in
if type == "type" {
return object.type.lowercased().contains(text.lowercased())
} else {
return object.type.lowercased().contains(text.lowercased())
}
})
DispatchQueue.main.async {
self.collectionView.reloadData()
self.collectionView.layoutSubviews()
}
}
func populateCollectionView() {
// load data into dataArray
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if isFiltering {
// during searching this will be triggered and return the correct count for the filteredData
return filteredData.count
} else {
return dataArray.count
}
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! CustomCell
var object: CustomObject
// isFiltering is always false even when searching
if isFiltering {
// never called
object = filteredData[indexPath.row]
} else {
// always called even when searching
object = dataArray[indexPath.row]
}
// do cell things here
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.frame.size.width - 8, height: 120)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 4
}
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
cell.contentView.layer.masksToBounds = true
let radius = cell.contentView.layer.cornerRadius
cell.layer.shadowPath = UIBezierPath(roundedRect: cell.bounds, cornerRadius: radius).cgPath
}
}
Here's the code for MainFrame
class MainFrame: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let searchController = UISearchController(searchResultsController: nil)
let cellId = "cellId"
let childFrameCell1Id = "cell1Id"
let childFrameCell2Id = "cell2Id"
var childFrameCell1: ChildFrameCell1!
var childFrameCell2: ChildFrameCell2!
lazy var topBar: CustomTopBar = {
let tb = CustomTopBar()
tb.mainFrame = self
return tb
}() // Top bar sliding indicator
override func viewDidLoad() {
super.viewDidLoad()
configureView()
configureSearchBar()
configureCollectionView()
setupTopBar()
}
func configureCollectionView() {
if let flowLayout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.scrollDirection = .horizontal
flowLayout.minimumLineSpacing = 0
flowLayout.minimumInteritemSpacing = 0
}
collectionView.backgroundColor = .white
collectionView.register(ChildFrameCell1.self, forCellWithReuseIdentifier: childFrameCell1Id)
collectionView.register(ChildFrameCell2.self, forCellWithReuseIdentifier: childFrameCell2Id)
collectionView.translatesAutoresizingMaskIntoConstraints = false
collectionView.isPagingEnabled = true
collectionView.showsHorizontalScrollIndicator = false
collectionView.collectionViewLayout.invalidateLayout()
collectionView.contentInset = UIEdgeInsets(top: 45, left: 0, bottom: 0, right: 0)
collectionView.scrollIndicatorInsets = UIEdgeInsets(top: 45, left: 0, bottom: 0, right: 0)
collectionView.contentInsetAdjustmentBehavior = UIScrollView.ContentInsetAdjustmentBehavior.never
childFrameCell1 = ChildFrameCell1()
childFrameCell2 = ChildFrameCell2()
}
func setupTopBar() {
// add top bar
}
func configureView() {
// set up view
}
func configureSearchBar() {
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "Search"
searchController.searchBar.tintColor = .white
searchController.searchBar.barTintColor = .white
if let tf = searchController.searchBar.value(forKey: "searchField") as? UITextField {
tf.textColor = UIColor.white
if let backgroundView = tf.subviews.first {
backgroundView.backgroundColor = .white
backgroundView.layer.cornerRadius = 10
backgroundView.clipsToBounds = true
}
}
navigationItem.searchController = searchController
definesPresentationContext = true
searchController.searchBar.scopeButtonTitles = ["Type1", "Type2"]
searchController.searchBar.delegate = self
}
func searchBarIsEmpty() -> Bool {
return searchController.searchBar.text?.isEmpty ?? true
}
func isFiltering() -> Bool {
let searchBarScopeIsFiltering = searchController.searchBar.selectedScopeButtonIndex != 0
return searchController.isActive && (!searchBarIsEmpty() || searchBarScopeIsFiltering)
}
func filterContentForSearchText(_ searchText: String, scope: String = "Location") {
let visibleRect = CGRect(origin: collectionView.contentOffset, size: collectionView.bounds.size)
let visiblePoint = CGPoint(x: visibleRect.midX, y: visibleRect.midY)
let visibleIndexPath = collectionView.indexPathForItem(at: visiblePoint)
if visibleIndexPath?.row == 0 {
// find the current view and parse search text into childFrame
childFrameCell1.searchTypeAndText(type: scope, text: searchText, filtering: isFiltering())
} else {
childFrameCell2.searchTypeAndText(type: scope, text: searchText, filtering: isFiltering())
}
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 2 // 2 pages
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let id: String
currentView = indexPath.item
if currentView == 0 {
id = childFrameCell1Id
} else {
id = childFrameCell2Id
}
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: id, for: indexPath) as! ChildFrameCell1
cell.mainFrame = self
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height - 50)
}
}
extension MainFrame: UISearchResultsUpdating {
func updateSearchResults(for searchController: UISearchController) {
let searchBar = searchController.searchBar
let scope = searchBar.scopeButtonTitles![searchBar.selectedScopeButtonIndex]
filterContentForSearchText(searchController.searchBar.text!, scope: scope)
}
}
}
extension MainFrame: UISearchBarDelegate {
func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
filterContentForSearchText(searchBar.text!, scope: searchBar.scopeButtonTitles![selectedScope])
}
}
ChildFrameCell2 is a subclass of ChildFrameCell1
When i enter text in the search bar in the MainFrame, it doesn't reload the collectionView to the new filteredData even if filteredData contains data.
I've been trying many ways to do this but still unable to reload the collectionView.
I even tried using DispatchGroup but the result is still the same. Filtering is not an issue, everything works accordingly except for reloading the collectionView.
Thank you for reading this lengthy post.
If you need the code from the MainFrame do let me know.

How to fix images disappearing from UICollectionViewCell on scroll

enter code hereI'm creating an application that requires a UICollectionView inside a UICollectionViewCell. I've successfully added the UICollectionView and all of its delegate methods within the cell and, on initial load, everything loads correctly. However, as soon as the user attempts to scroll further down in the main UICollectionView, the cells which held the inner UICollectionView, essentially, loose their view. An interesting detail to note is that the issue only rears its head when the user scrolls at a non-snail rate. If the scroll slow enough, the cells will load correctly. Otherwise, the cells will become malformed.
Unfortunately, I've been dealing with this problem for quite a while, as in close to/more than a month at this point. I've tried just about every solution proposed on StackOverflow, Medium articles, YouTube tutorials, etc. but have yet to find the working solution.
This behavior is not exhibited without the conditional rendering if I always add the UICollectionView as a subview.
An important detail to note is that my cells are vertically self-sizing, and every cell is not guaranteed to contain an inner UICollectionView. I suspect part of my issue is born from my handling of this conditional rendering (i.e. if the cell's datasource has images, add the UICollectionView as a subview. Otherwise, don't add it at all).
Additionally, I'm using imported assets in my Xcode project as images. I'm not making any async calls that otherwise may attribute to the images not being fetched and the datasource having 0 images when it should have > 0. My logs in my parseDatasource(withDatasource datasource: (String, [UIImage]) function are showing that datasource.1 contains an array of images in the cells that should have images, as expected. I'm beyond stumped at this point and a bit more than slightly frustrated.
My main UIViewController controlling the cells:
class ExperimentalViewController: UIViewController {
private let cellReuseId = "cellReuseId"
fileprivate var data = [(String, [UIImage])]()
fileprivate let strings = [<a large array of strings>]
private let collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let collection = UICollectionView(frame: .zero, collectionViewLayout: layout)
collection.backgroundColor = .clear
collection.alwaysBounceVertical = true
collection.contentInsetAdjustmentBehavior = .always
return collection
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
setupDummyData()
setupCollectionView()
}
private func setupDummyData() {
for (i, str) in strings.enumerated() {
var images = [UIImage]()
if i % 2 == 0 {
images = [UIImage(named: "boxed-water-is-better-1464052-unsplash")!, UIImage(named: "boxed-water-is-better-1464052-unsplash")!, UIImage(named: "boxed-water-is-better-1464052-unsplash")!]
}
data.append((str, images))
}
}
private func setupCollectionView() {
if #available(iOS 13.0, *) {
let size = NSCollectionLayoutSize(
widthDimension: NSCollectionLayoutDimension.fractionalWidth(1),
heightDimension: NSCollectionLayoutDimension.estimated(440)
)
let item = NSCollectionLayoutItem(layoutSize: size)
let group = NSCollectionLayoutGroup.horizontal(layoutSize: size, subitems: [item])
let section = NSCollectionLayoutSection(group: group)
section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 8, bottom: 0, trailing: 8)
section.interGroupSpacing = 5
let layout = UICollectionViewCompositionalLayout(section: section)
collectionView.collectionViewLayout = layout
} else {
let layout = ExperimentalFlowLayout()
collectionView.collectionViewLayout = layout
}
collectionView.delegate = self
collectionView.dataSource = self
collectionView.register(ExperimentalCell.self, forCellWithReuseIdentifier: cellReuseId)
view.addSubview(collectionView)
collectionView.anchor(top: view.topAnchor, leading: view.leadingAnchor, bottom: view.bottomAnchor, trailing: view.trailingAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
}
}
extension ExperimentalViewController: UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return data.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellReuseId, for: indexPath) as! ExperimentalCell
cell.index = indexPath
cell.backgroundColor = .yellow
cell.setupViews(withDatasource: data[indexPath.item])
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 20
}
}
My UICollectionViewCell subclass
class ExperimentalCell: UICollectionViewCell {
// https://stackoverflow.com/questions/37782659/swift-ios-uicollectionview-images-mixed-up-after-fast-scroll/37784212
// http://www.thomashanning.com/the-most-common-mistake-in-using-uitableview/
private let imageCellReuseId = "imageCellReuseId"
var index: IndexPath?
var images = [UIImage]()
private let titleLabel: UILabel = {
let label = UILabel()
label.numberOfLines = 0
return label
}()
private let label: UILabel = {
let label = UILabel()
label.numberOfLines = 0
return label
}()
let collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
let collection = UICollectionView(frame: .zero, collectionViewLayout: layout)
collection.backgroundColor = .clear
return collection
}()
override init(frame: CGRect) {
super.init(frame: frame)
print("RYANLOG \(index?.row) INIT")
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func prepareForReuse() {
super.prepareForReuse()
images = []
imageView.image = nil
collectionView.delegate = nil
collectionView.dataSource = nil
titleLabel.text = nil
label.text = nil
setupViews(withDatasource: nil)
}
func setupViews(withDatasource datasource: (String, [UIImage])?) {
if datasource != nil {
parseDatasource(datasource!)
}
contentView.addSubview(titleLabel)
titleLabel.anchor(top: contentView.topAnchor, leading: contentView.leadingAnchor, bottom: nil, trailing: contentView.trailingAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
contentView.addSubview(label)
if images.count > 0 {
titleLabel.text = "Images"
label.text = String(images.count)
label.anchor(top: titleLabel.bottomAnchor, leading: contentView.leadingAnchor, bottom: nil, trailing: contentView.trailingAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
setupCollectionView()
contentView.addSubview(collectionView)
collectionView.anchor(top: label.bottomAnchor, leading: contentView.leadingAnchor, bottom: contentView.bottomAnchor, trailing: contentView.trailingAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 200)
} else {
titleLabel.text = "No Images"
label.anchor(top: titleLabel.bottomAnchor, leading: contentView.leadingAnchor, bottom: contentView.bottomAnchor, trailing: contentView.trailingAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
}
}
private func parseDatasource(_ datasource: (String, [UIImage])) {
label.text = datasource.0
images = datasource.1
print("RYANLOG \(index?.row) Images:", images.count)
}
// MARK: - Used for self-sizing on <= iOS 12
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
layoutIfNeeded()
let layoutAttributes = super.preferredLayoutAttributesFitting(layoutAttributes)
layoutAttributes.bounds.size = systemLayoutSizeFitting(UIView.layoutFittingCompressedSize, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
return layoutAttributes
}
}
extension ExperimentalCell: UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
fileprivate func setupCollectionView() {
collectionView.delegate = self
collectionView.dataSource = self
collectionView.register(ScrollableImageView.self, forCellWithReuseIdentifier: imageCellReuseId)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return images.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: imageCellReuseId, for: indexPath) as! ScrollableImageView
cell.imageView.image = images[indexPath.item]
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 200, height: 200)
}
}
Please excuse the use of print("RYANLOG ...)s. I've been using them for debugging and figured they might be helpful in displaying the areas I believe might be part of the issue.
ScrollableImageView is a subclass of UIView. If you think seeing the code contained within this class would be helpful, please let me know!
Any help is greatly appreciated!
A gif demonstrating the flawed behavior:
https://imgur.com/a/btAXPca
Update: I finally solved this using two different reuse identifiers: "cellRuseId" and "imageCellReuseId". I'm still not sure whether this is the correct solution, but, now my collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) looks like so:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let reuseId = data[indexPath.item].1.count > 0 ? imageCellReuseId : cellReuseId
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseId, for: indexPath) as! ExperimentalCell
cell.index = indexPath
cell.backgroundColor = .yellow
cell.setupViews(withDatasource: data[indexPath.item])
return cell
}
My collection view scrolls correctly and is properly reusing the cells. I won't accept this answer as it's not the most elegant (especially if you have multiple variations of the same cell) so if someone has a better answer, please give a response!

Can someone explain why my CollectionView cells only appear in this scenario?

I am animating a UIView from another class however I'm getting different results from each and was hoping someone could explain why. When I trigger EditSongLauncher from handleEdit1, the 4 collectionview cells are not showing. However when I trigger EditSongLauncher from handleEdit2, I get all 4 cells showing.
I don't understand why handleEdit1 doesn't work as it is essentially doing the same thing when it calls setupViews()... I would prefer to use handleEdit1 as it allows for cleaner code so was hoping someone could explain why or tell me why the 4 cells arn't appearing for this function.
#objc func handleEdit1() {
let editLauncher = EditSongLauncher()
editLauncher.setupViews()
}
#objc func handleEdit2() {
if let window = UIApplication.shared.keyWindow {
let editLauncher = EditSongLauncher.init(frame: CGRect(x: 0, y: 0, width: collectionView.frame.width, height: collectionView.frame.height))
window.addSubview(editLauncher)
}
}
class EditSongLauncher: UIView, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
let dimmedView: UIView = {
let view = UIView()
view.backgroundColor = UIColor(white: 0, alpha: 0.5)
view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleSave(sender:))))
view.isUserInteractionEnabled = true
return view
}()
let collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .white
return cv
}()
func setupViews() {
if let window = UIApplication.shared.keyWindow {
let height: CGFloat = 400
let y = window.frame.height - height
collectionView.frame = CGRect(x: 0, y: window.frame.height, width: window.frame.width, height: height)
dimmedView.frame = window.frame
dimmedView.alpha = 0
window.addSubview(dimmedView)
window.addSubview(collectionView)
UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseOut, animations: {
self.dimmedView.alpha = 1
self.collectionView.frame = CGRect(x: 0, y: y, width: self.collectionView.frame.width, height: self.collectionView.frame.height)
}, completion: nil)
}
}
#objc func handleSave(sender: UITapGestureRecognizer) {
print("Handling save")
UIView.animate(withDuration: 0.5) {
self.dimmedView.alpha = 0
}
}
override init(frame: CGRect) {
super.init(frame: frame)
collectionView.dataSource = self
collectionView.delegate = self
collectionView.register(EditSongCell.self, forCellWithReuseIdentifier: cellId)
setupViews()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 4
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
cell.backgroundColor = .blue
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width, height: 50)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}

Issue With Passing Data Programmatically Swift

I am having trouble passing data from one UICollectionViewController to another UICollectionViewController programmatically.
Currently my setup is as follows:
The UICollectionViewController that is passing the data (RestaurantController)
1a. A UICollectionViewCell (RestaurantCell)
this UICollectionViewCell has a nested UICollectionViewController within it with another custom UICollectionViewCell (RestaurantCollectionViewCell)
The UICollectionViewController that is receiving the data (MenuController)
2a. A UICollectionViewCell (MenuCell)
Inside of my RestaurantCell I am loading data from JSON and appending it a new array as called restaurants: var restaurants = [RestaurantModel](). But when I try to load the restaurant name or any of the restaurant objects in my MenuController using var restaurant: RestaurantModel?, I get nil values. I have a feeling either my setup is incorrect or I'm making a stupid mistake somewhere. Perhaps both. I have pasted my code below for each class.
Where the values are returning nil inside of MenuController:
print("Restaurant Name:", restaurant?.name)
print("Restaurant Id:", restaurant?.id)
Is the custom delegation causing the issue?
You help and advice is greatly appreciated!
Inside of my RestaurantController:
import UIKit
import FBSDKLoginKit
class RestaurantController: UICollectionViewController, UICollectionViewDelegateFlowLayout, SWRevealViewControllerDelegate, UISearchBarDelegate, RestaurantDelegate {
var restaurantCell: RestaurantCell?
private let restaurantCellId = "restaurantCellId"
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.backgroundColor = UIColor.qpizzaWhite()
collectionView?.register(RestaurantCell.self, forCellWithReuseIdentifier: restaurantCellId)
if self.revealViewController() != nil {
navigationItem.leftBarButtonItem = UIBarButtonItem(image: #imageLiteral(resourceName: "icon_menu_24dp").withRenderingMode(.alwaysOriginal), style: .plain, target: self.revealViewController(), action: #selector(SWRevealViewController.revealToggle(_:)))
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
}
// FIXME: issue with this...navigationcontroller is presenting, not pushing ontop of stack view
func didTapRestaurantCell(cell: RestaurantCell) {
print("Did Tap Restaurant Cell - Restaurant Controller")
let layout = UICollectionViewFlowLayout()
let controller = MenuController(collectionViewLayout: layout)
navigationController?.pushViewController(controller, animated: true)
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: restaurantCellId, for: indexPath) as! RestaurantCell
cell.delegate = self
return cell
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 1
}
}
Inside of my RestaurantCell:
protocol RestaurantDelegate {
func didTapRestaurantCell(cell: RestaurantCell)
}
class RestaurantCell: BaseCell, UISearchBarDelegate, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
var delegate: RestaurantDelegate?
var restaurants = [RestaurantModel]()
var filteredRestaurants = [RestaurantModel]()
private let restaurantCollectionViewCell = "restaurantCollectionViewCell"
private let activityIndicator = UIActivityIndicatorView()
lazy var searchBar: UISearchBar = {
let sb = UISearchBar()
sb.placeholder = "Search Restaurant"
sb.barTintColor = .white
UITextField.appearance(whenContainedInInstancesOf: [UISearchBar.self]).backgroundColor = UIColor.qpizzaWhite()
sb.delegate = self
return sb
}()
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .white
return cv
}()
override func setupViews() {
super.setupViews()
collectionView.register(RestaurantCollectionViewCell.self, forCellWithReuseIdentifier: restaurantCollectionViewCell)
collectionView.delegate = self
collectionView.dataSource = self
backgroundColor = UIColor.qpizzaRed()
addSubview(searchBar)
addSubview(collectionView)
_ = searchBar.anchor(topAnchor, left: leftAnchor, bottom: nil, right: rightAnchor, topConstant: 4, leftConstant: 4, bottomConstant: 0, rightConstant: 4, widthConstant: 0, heightConstant: 50)
_ = collectionView.anchor(searchBar.bottomAnchor, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
loadRestaurants()
}
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
print(searchText)
filteredRestaurants = self.restaurants.filter({ (restaruant: RestaurantModel) -> Bool in
return restaruant.name?.lowercased().range(of: searchText.lowercased()) != nil
})
self.collectionView.reloadData()
}
// MARK - Helper Methods
func loadRestaurants() {
showActivityIndicator()
APIManager.shared.getRestaurants { (json) in
if json != .null {
// print("Restaurant JSON:", json)
self.restaurants = []
if let restaurantList = json["restaurants"].array {
for item in restaurantList {
let restaurant = RestaurantModel(json: item)
self.restaurants.append(restaurant)
}
self.collectionView.reloadData()
self.hideActivityIndicator()
}
} else {
print("Error loading JSON into Restaurant ViewController")
}
}
}
func loadImage(imageView: UIImageView, urlString: String) {
let imageUrl: URL = URL(string: urlString)!
URLSession.shared.dataTask(with: imageUrl) { (data, response, error) in
if let error = error {
print("Error loading image for Restaurant Controller:", error.localizedDescription)
}
guard let data = data, error == nil else { return }
DispatchQueue.main.async(execute: {
imageView.image = UIImage(data: data)
})
}.resume()
}
func showActivityIndicator() {
activityIndicator.frame = CGRect(x: 0.0, y: 0.0, width: 40.0, height: 40.0)
activityIndicator.center = center
activityIndicator.hidesWhenStopped = true
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.whiteLarge
activityIndicator.color = UIColor.qpizzaGold()
addSubview(activityIndicator)
activityIndicator.startAnimating()
}
func hideActivityIndicator() {
activityIndicator.stopAnimating()
}
//MARK: CollectionView Delegate & DataSource Methods
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: restaurantCollectionViewCell, for: indexPath) as! RestaurantCollectionViewCell
let restaurant: RestaurantModel
if searchBar.text != "" {
restaurant = filteredRestaurants[indexPath.item]
} else {
restaurant = restaurants[indexPath.item]
}
cell.restaurantNameLabel.text = restaurant.name
cell.restaurantAddressLabel.text = restaurant.address
if let logoName = restaurant.logo {
let url = "\(logoName)"
loadImage(imageView: cell.restaurantLogoImageView, urlString: url)
}
return cell
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if searchBar.text != "" {
return self.filteredRestaurants.count
}
return self.restaurants.count
}
//FIXME: Restaurant Name Navigation Title is still not be passed from RestaurantCell to MenuController
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Did Select Item - Restaurant Cell")
let layout = UICollectionViewFlowLayout()
let controller = MenuController(collectionViewLayout: layout)
controller.restaurant = self.restaurants[indexPath.item]
print("Controller", controller.restaurant) // Optional(QpizzaDelivery.RestaurantModel)
print("Restaurant:", self.restaurants) // [QpizzaDelivery.RestaurantModel, QpizzaDelivery.RestaurantModel, QpizzaDelivery.RestaurantModel]
print("IndexPath:", self.restaurants[indexPath.item]) // QpizzaDelivery.RestaurantModel
delegate?.didTapRestaurantCell(cell: self)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width, height: 200)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0.5
}
}
Inside of my MenuController:
import UIKit
class MenuController: UICollectionViewController, UICollectionViewDelegateFlowLayout, SWRevealViewControllerDelegate {
private let menuCellId = "menuCellId"
var restaurant: RestaurantModel?
var menuItems = [MenuItemsModel]()
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.backgroundColor = UIColor.qpizzaWhite()
collectionView?.register(MenuCell.self, forCellWithReuseIdentifier: menuCellId)
collectionView?.alwaysBounceVertical = true
if self.revealViewController() != nil {
navigationItem.leftBarButtonItem = UIBarButtonItem(image: #imageLiteral(resourceName: "menu2-black-32").withRenderingMode(.alwaysOriginal), style: .plain, target: self.revealViewController(), action: #selector(SWRevealViewController.revealToggle(_:)))
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
print("Restaurant Name:", restaurant?.name) // returns nil
if let restaurantName = restaurant?.name {
self.navigationItem.title = restaurantName
}
loadMenuItems()
}
func loadMenuItems() {
print("Restaurant Id:", restaurant?.id) // returns nil
if let restaurantId = restaurant?.id {
print("RestaurantId:", restaurantId)
}
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: menuCellId, for: indexPath) as! MenuCell
return cell
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let layout = UICollectionViewFlowLayout()
let controller = MenuDetailsController(collectionViewLayout: layout)
navigationController?.pushViewController(controller, animated: true)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: 120)
}
}
Inside of my MenuCell:
import UIKit
class MenuCell: BaseCell {
let restaurantLabel: UILabel = {
let label = UILabel()
label.text = "Restaurant King"
label.font = UIFont.boldSystemFont(ofSize: 16)
label.textColor = .black
label.numberOfLines = 0
return label
}()
let mealImageView: UIImageView = {
let iv = UIImageView()
iv.image = #imageLiteral(resourceName: "button_chicken").withRenderingMode(.alwaysOriginal)
iv.contentMode = .scaleAspectFill
iv.clipsToBounds = true
return iv
}()
let mealDetailsLabel: UILabel = {
let label = UILabel()
label.text = "Grass fed grass, American cheese, and friez"
label.font = UIFont.boldSystemFont(ofSize: 12)
label.textColor = UIColor.qpizzaBlack()
label.numberOfLines = 0
return label
}()
let mealPriceLabel: UILabel = {
let label = UILabel()
label.text = "$12.00"
label.font = UIFont.boldSystemFont(ofSize: 12)
label.textColor = UIColor.qpizzaBlack()
return label
}()
let sepereatorView: UIView = {
let view = UIView()
view.backgroundColor = UIColor.lightGray
return view
}()
override func setupViews() {
super.setupViews()
backgroundColor = UIColor.qpizzaWhite()
addSubview(restaurantLabel)
addSubview(mealImageView)
addSubview(mealDetailsLabel)
addSubview(mealPriceLabel)
addSubview(sepereatorView)
_ = mealImageView.anchor(topAnchor, left: nil, bottom: nil, right: rightAnchor, topConstant: 14, leftConstant: 0, bottomConstant: 0, rightConstant: 12, widthConstant: 60, heightConstant: 60)
_ = restaurantLabel.anchor(topAnchor, left: leftAnchor, bottom: nil, right: mealImageView.leftAnchor, topConstant: 14, leftConstant: 12, bottomConstant: 0, rightConstant: 10, widthConstant: 0, heightConstant: 20)
_ = mealDetailsLabel.anchor(restaurantLabel.bottomAnchor, left: leftAnchor, bottom: nil, right: mealImageView.leftAnchor, topConstant: 12, leftConstant: 12, bottomConstant: 0, rightConstant: 10, widthConstant: 0, heightConstant: 30)
_ = mealPriceLabel.anchor(mealDetailsLabel.bottomAnchor, left: leftAnchor, bottom: nil, right: rightAnchor, topConstant: 10, leftConstant: 12, bottomConstant: 10, rightConstant: 10, widthConstant: 0, heightConstant: 20)
_ = sepereatorView.anchor(nil, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor, topConstant: 0, leftConstant: 20, bottomConstant: 4, rightConstant: 20, widthConstant: 0, heightConstant: 1)
}
}
Just a quick look, declaring a variable of the correct type is the start. But you actually have to do an assignment (=) to move data or the class reference from once class to the next.
func didTapRestaurantCell(cell: RestaurantCell) {
print("Did Tap Restaurant Cell - Restaurant Controller")
let layout = UICollectionViewFlowLayout()
let controller = MenuController(collectionViewLayout: layout)
navigationController?.pushViewController(controller, animated: true)
// you need to set the restaurant attribute of your new
// controller
let indexPath = indexPath(for: cell)
controller.restaurant = self.restaurants[indexPath.item]
}
Thank you to everyone who commented and assisted me in figuring this out. I was able to solve my issue by changing my protocol and passing the controller as a parameter.
In RestaurantCell:
protocol RestaurantDelegate {
func didTapRestaurantCell(cell: RestaurantCell, withMenuController: MenuController)
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Did Select Item - Restaurant Cell")
let layout = UICollectionViewFlowLayout()
let controller = MenuController(collectionViewLayout: layout)
controller.restaurant = self.restaurants[indexPath.item]
delegate?.didTapRestaurantCell(cell: self, withMenuController: controller)
}
In RestaurantController:
func didTapRestaurantCell(cell: RestaurantCell, withMenuController controller: MenuController) {
print("Did Tap Restaurant Cell - Restaurant Controller")
navigationController?.pushViewController(controller, animated: true)
}

How to animate when swiping through collection view

I have a collectionView inside of a ViewController. When I swipe, it swipes to another Collection View Cell which is the height and width of the view.frame
I want to have an animation that starts whenever I start swiping, to then finish whenever the collection view locks into the centre of a cell just like the gif below. I don't have a label or textview in my code but could you point me in the right direction on how I would do this? Here's my relevent code:
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
layout.minimumLineSpacing = 0
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .white
cv.dataSource = self
cv.delegate = self
cv.isPagingEnabled = true
cv.showsHorizontalScrollIndicator = false
return cv
}()
let cellId = "cellId"
let loginCellId = "loginCellId"
let pages: [Page] = {
let firstPage = Page(imageName: "introduction_1")
let secondPage = Page(imageName: "introduction_2")
let thirdPage = Page(imageName: "introduction_3")
let fourthPage = Page(imageName: "introduction_4")
return [firstPage, secondPage, thirdPage, fourthPage]
}()
lazy var pageControl: UIPageControl = {
let pc = UIPageControl()
pc.pageIndicatorTintColor = .lightGray
pc.currentPageIndicatorTintColor = .darkGray
pc.numberOfPages = self.pages.count + 1
return pc
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(collectionView)
view.addSubview(pageControl)
_ = pageControl.anchor(nil, left: view.leftAnchor, bottom: view.bottomAnchor, right: view.rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 40)
collectionView.anchorToTop(view.topAnchor, left: view.leftAnchor, bottom: view.bottomAnchor, right: view.rightAnchor)
registerCells()
}
func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
let pageNumber = Int(targetContentOffset.pointee.x / view.frame.width)
pageControl.currentPage = pageNumber
}
fileprivate func registerCells() {
collectionView.register(PageCell.self, forCellWithReuseIdentifier: cellId)
collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: loginCellId)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return pages.count + 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.item == pages.count {
let loginCell = collectionView.dequeueReusableCell(withReuseIdentifier: loginCellId, for: indexPath)
return loginCell
}
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! PageCell
let page = pages[indexPath.item]
cell.page = page
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height)
}
}
class PageCell: UICollectionViewCell {
var page: Page? {
didSet {
guard let page = page else {
return
}
imageView.image = UIImage(named: page.imageName)
}
}
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
let imageView: UIImageView = {
let iv = UIImageView()
iv.contentMode = .scaleAspectFill
iv.backgroundColor = .yellow
iv.clipsToBounds = true
return iv
}()
func setupViews() {
addSubview(imageView)
imageView.anchorToTop(topAnchor, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
From my standpoint, in your case it is better to use UIPageViewController instead of UICollectionView. It has a whole bunch of features for you to implement the UI you've shown above. There is a good tutorial on this topic - https://www.veasoftware.com/posts/uipageviewcontroller-in-swift-xcode-62-ios-82-tutorial?rq=page

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