Reputation: 29
I am using UICollectionView
didSelectItemAt
to update a UI label that I set up in my HomeController. So basically when I press the cell I want my text to be updated. However the text doesn't update, I have debugged though and the value changes. I have tried everything, both setNeedsDisplay()
and running through main thread
(which it already does)
I have quite a lot of code in these classes (I don't use storyboard) but this is the label setup (sits in HomeController):
import UIKit
import CoreData
class mainHomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
static let sharedInstance = HomeController()
override func viewDidLoad() {
super.viewDidLoad()
setupBasketBar()
}
let totNumber: UILabel = {
let label = UILabel()
label.text = "0"
label.numberOfLines = 2
return label
}()
func setupBasketBar() {
self.view.addSubview(totNumber)
totNumber.translatesAutoresizingMaskIntoConstraints = false
totNumber.leadingAnchor.constraint(equalTo: view.leadingAnchor,constant: 330).isActive = true
totNumber.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
totNumber.bottomAnchor.constraint(equalTo: view.bottomAnchor,constant: 0).isActive = true
totNumber.heightAnchor.constraint(equalTo: view.heightAnchor,multiplier: 5).isActive = true
}
}
and this sits in the feed cell:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
HomeController.sharedInstance.totNumber.text = ("234")
HomeController.sharedInstance.totNumber.setNeedsDisplay()
}
I have edited out the relevant parts.
This is the whole code for the HomeController:
import UIKit
import CoreData
class HomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
static let sharedInstance = HomeController()
let cellId = "cellId"
let trendingCellId = "trendingCellId"
let subscriptionCellId = "subscriptionCellId"
let titles = ["Home", "Trending", "Subscriptions", "Account"]
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.isTranslucent = false
let titleLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 30, height: view.frame.height))
titleLabel.text = "Home"
titleLabel.textColor = UIColor.black
titleLabel.font = UIFont.systemFont(ofSize: 20)
navigationItem.titleView = titleLabel
setupCollectionView()
setupMenuBar()
setupBasketBar()
}
func setupCollectionView() {
if let flowLayout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.scrollDirection = .horizontal
flowLayout.minimumLineSpacing = 0
}
collectionView?.backgroundColor = UIColor.white
collectionView?.register(FeedCell.self, forCellWithReuseIdentifier: cellId)
collectionView?.register(TrendingCell.self, forCellWithReuseIdentifier: trendingCellId)
collectionView?.register(SubscriptionCell.self, forCellWithReuseIdentifier: subscriptionCellId)
collectionView?.contentInset = UIEdgeInsetsMake(50, 0, 0, 0)
collectionView?.scrollIndicatorInsets = UIEdgeInsetsMake(50, 0, 0, 0)
collectionView?.isPagingEnabled = true
}
lazy var settingsLauncher: SettingsLauncher = {
let launcher = SettingsLauncher()
launcher.homeController = self
return launcher
}()
func handleMore() {
//show menu
settingsLauncher.showSettings()
}
func showControllerForSetting(_ setting: Setting) {
let dummySettingsViewController = UIViewController()
dummySettingsViewController.view.backgroundColor = UIColor.white
dummySettingsViewController.navigationItem.title = setting.name.rawValue
navigationController?.navigationBar.tintColor = UIColor.white
navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
navigationController?.pushViewController(dummySettingsViewController, animated: true)
}
func handleSearch() {
scrollToMenuIndex(2)
}
func scrollToMenuIndex(_ menuIndex: Int) {
let indexPath = IndexPath(item: menuIndex, section: 0)
collectionView?.scrollToItem(at: indexPath, at: UICollectionViewScrollPosition(), animated: true)
setTitleForIndex(menuIndex)
}
fileprivate func setTitleForIndex(_ index: Int) {
if let titleLabel = navigationItem.titleView as? UILabel {
titleLabel.text = " \(titles[index])"
}
}
lazy var menuBar: MenuBar = {
let mb = MenuBar()
mb.homeController = self
return mb
}()
func buttonAction(sender: UIButton!) {
let btnsendtag: UIButton = sender
if btnsendtag.tag == 1 {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc: UINavigationController = storyboard.instantiateViewController(withIdentifier: "NewViewController") as! UINavigationController
self.present(vc, animated: true, completion: nil)
}
}
let totLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 21))
let btn: UIButton = UIButton(frame: CGRect(x: 0, y: 600, width: 500, height: 80))
func setupBasketBar() {
//Checkout button
btn.backgroundColor = UIColor.rgb(36, green: 51, blue: 70)
btn.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
btn.tag = 1
self.view.addSubview(btn)
btn.setTitleColor(UIColor.yellow, for: .normal)
//Button that updates the current amount
totLabel.text = "Total amount"
totLabel.textColor = UIColor.white
self.view.addSubview(totLabel)
//constraints
totLabel.translatesAutoresizingMaskIntoConstraints = false
totLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
totLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
totLabel.bottomAnchor.constraint(equalTo: view.bottomAnchor,constant: 0).isActive = true
totLabel.heightAnchor.constraint(equalTo: view.heightAnchor,multiplier: 0.1).isActive = true
//oldconstraints
/* self.view.addSubview(totNumber)
totNumber.translatesAutoresizingMaskIntoConstraints = false
totNumber.leadingAnchor.constraint(equalTo: view.leadingAnchor,constant: 330).isActive = true
totNumber.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
totNumber.bottomAnchor.constraint(equalTo: view.bottomAnchor,constant: 0).isActive = true
totNumber.heightAnchor.constraint(equalTo: view.heightAnchor,multiplier: 0.1).isActive = true*/
}
fileprivate func setupMenuBar() {
navigationController?.hidesBarsOnSwipe = false
let redView = UIView()
redView.backgroundColor = UIColor.rgb(36, green: 51, blue: 70)
view.addSubview(redView)
view.addConstraintsWithFormat("H:|[v0]|", views: redView)
view.addConstraintsWithFormat("V:[v0(50)]", views: redView)
view.addSubview(menuBar)
view.addConstraintsWithFormat("H:|[v0]|", views: menuBar)
view.addConstraintsWithFormat("V:[v0(50)]", views: menuBar)
menuBar.topAnchor.constraint(equalTo: topLayoutGuide.bottomAnchor).isActive = true
}
override func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
let index = targetContentOffset.pointee.x / view.frame.width
let indexPath = IndexPath(item: Int(index), section: 0)
menuBar.collectionView.selectItem(at: indexPath, animated: true, scrollPosition: UICollectionViewScrollPosition.centeredHorizontally)
setTitleForIndex(Int(index))
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let identifier: String
if indexPath.item == 1 {
identifier = trendingCellId
} else if indexPath.item == 2 {
identifier = subscriptionCellId
} else {
identifier = cellId
}
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height - 50)
}
}
Upvotes: 0
Views: 621
Reputation: 2307
Okay! looking at the updated code snippet the sharedInstance
singleton is definitely not needed - I'd remove that completely.
The didSelectItemAt
method then just needs to be this:
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
totNumber.text = "234"
}
Upvotes: 1
Reputation: 17732
I'm guessing your sharedInstance
variable is a new instance of the view controller, this is separate from the one that is allocated and displayed from storyboards or segues. You should set sharedInstance
equal to self
inside viewDidLoad
Upvotes: 0