How to change collectionview cells color based on device theme (following my color scheme) - ios

Question

Overview:
I'm building a keyboard Extension using collectionviews. I want the cells to change color based on the device theme (light/dark). At the moment, when I set the color scheme for my collectionview cells they don't work. I'm marking the problematic parts of my code with a "///" comment.
Resources:
I found this RayWenderlich project and I liked how they handled the color changing stuff so I copied it.
My code:
I have 3 classes:
KeyboardViewController
Custom View containing keyboard buttons
Custom collectionview cells
CollectionView cell
class KeyboardKeys: UICollectionViewCell {
var defaultColor = UIColor.white
var highlighColor = UIColor.lightGray.withAlphaComponent(0.6)
let label: UILabel = {
let iv = UILabel()
iv.translatesAutoresizingMaskIntoConstraints = false
iv.contentMode = .scaleAspectFit
iv.font = UIFont.systemFont(ofSize: 20)
iv.clipsToBounds = true
iv.numberOfLines = 1
iv.textAlignment = .center
return iv
}()
override init(frame: CGRect) {
super.init(frame: .zero)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() {
contentView.addSubview(label)
label.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
label.leftAnchor.constraint(equalTo: contentView.leftAnchor).isActive = true
label.rightAnchor.constraint(equalTo: contentView.rightAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
}
override func layoutSubviews() {
super.layoutSubviews()
backgroundColor = isHighlighted ? highlighColor : defaultColor
}
}
Custom View
class lettersKeyboard: UIView, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout{
var keyView: UICollectionView!
let letters = ["q", "w", "e", "r", "t", "y", "u", "i", "o", "p"]
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
private func commonInit(){
//If you find some errors it's because this is way different in my code. This is just a regulare collection view anyway
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical
keyView = UICollectionView(frame: CGRect(x: 0.0, y: 0.0 , width: frame.width, height: 280), collectionViewLayout: layout)
keyView.setCollectionViewLayout(layout, animated: true)
keyView.isScrollEnabled = false
keyView.register(KeyboardKeys.self, forCellWithReuseIdentifier: "collectionCellId")
keyView.delegate = self
keyView.dataSource = self
addSubview(keyView)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = keyView.dequeueReusableCell(withReuseIdentifier: "collectionCellId", for: indexPath) as! KeyboardKeys
cell.label.text = letters[indexPath.row]
return cell
}
///I guess something is wrong here
func setColorScheme(_ colorScheme: ColorScheme) {
let colorScheme = CColors(colorScheme: colorScheme)
for view in subviews {
if let cell = view as? KeyboardKeys {
cell.tintColor = colorScheme.buttonTextColor
cell.defaultColor = colorScheme.keysDefaultColor
cell.highlighColor = colorScheme.keysHighlightColor
}
}
}
}
Color scheme struct
enum ColorScheme {
case dark
case light
}
struct CColors {
let keysDefaultColor: UIColor
let keysHighlightColor: UIColor
let buttonTextColor: UIColor
init(colorScheme: ColorScheme) {
switch colorScheme {
case .light:
keysDefaultColor = .systemRed
//UIColor.white
keysHighlightColor = UIColor.lightGray.withAlphaComponent(0.6)
buttonTextColor = .black
case .dark:
keysDefaultColor = .systemBlue
// UIColor.gray.withAlphaComponent(0.5)
keysHighlightColor = UIColor.lightGray.withAlphaComponent(0.5)
buttonTextColor = .white
}
}
}
KeyboardViewController
class KeyboardViewController: UIInputViewController {
var letters : lettersKeyboard = {
let m = lettersKeyboard(frame: .zero)
m.translatesAutoresizingMaskIntoConstraints = false
m.backgroundColor = .clear
return m
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(letters)
letters.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
letters.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
letters.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
letters.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
//The rest is the default inputvc stuff
///Or here
override func textDidChange(_ textInput: UITextInput?) {
// The app has just changed the document's contents, the document context has been updated.
let colorScheme: ColorScheme
let proxy = self.textDocumentProxy
if proxy.keyboardAppearance == UIKeyboardAppearance.dark {
colorScheme = .dark
} else {
colorScheme = .light
}
letters.setColorScheme(colorScheme)
}
}
Question:
I don't know what I'm doing wrong since my code works with everything except for collectionview cells. I guess another way of doing this stuff exists. So how do I change my collectionView cells' color based on the device's theme following my color scheme?

Answer 1

You should really be reloading the collection view, rather than trying to find the subviews that are the keys, and updating those.
Pass in the colorScheme model to each cell and have the colors be set as a result of a reload.

Answer 2

A very kind guy helped me out and found this solution. The problem here is that I forgot the view's hierarchy.
CollectionView cell
override func layoutSubviews() {
super.layoutSubviews()
setupBackGround()
}
func setupBackGround(){
backgroundColor = isHighlighted ? highlighColor : defaultColor
}
KeyboardViewController
func setColorScheme(_ colorScheme: ColorScheme) {
let colorScheme = CColors(colorScheme: colorScheme)
for view in subviews {
func setToRootView(view: UIView) {
if let cell = view as? KeyboardKeys {
cell.tintColor = colorScheme.buttonTextColor
cell.defaultColor = colorScheme.keysDefaultColor
cell.highlighColor = colorScheme.keysHighlightColor
cell.setBackground()
return
}
guard view.subviews.count > 0 else {
return
}
view.subviews.forEach(setToRootView(view:))
}
setToRootView(view: self)
}