Arrlindii

protocol Reusable {
  func prepareForReuse()
}

Arrlindii

class UITableViewCell: UIView, Reusable {
  func prepareForReuse() { }
}

Arrlindii

class ObjectPool<T: Reusable> {
  private let maxElementCount: Int
  private let factory: () -> T
  
  public init(maxElementCount: Int, factory: @escaping () -> T) {
    self.factory = factory
    self.maxElementCount = maxElementCount
  }
}

Arrlindii

class ObjectPool<T: Reusable> {
    private let maxElementCount: Int
    private let factory: () -> T
    var elements = [T]()
    
    public init(maxElementCount: Int, factory: @escaping () -> T) {
        self.factory = factory
        self.maxElementCount = maxElementCount
    }
    

Arrlindii

func dequeueReusableCell(withIdentifier identifier: String) -> UITableViewCell {
    return pool.draw()
}

Arrlindii

func handleDidEndDisplayingCell(_ cell: UITableViewCell, forRowAt indexPath: IndexPath) {
    delegate.tableView(_ tableView: self, didEndDisplaying cell: cell, forRowAt indexPath: indexPath)
    pool.release(cell)
}

Arrlindii

class AppDefaults {
    static let shared = AppDefaults()
    private init() {
        //Private initialization to be sure that only one instance is created.
    }
}

Arrlindii

enum NotificationName {
    case emailChangeNotification
}


protocol StateChangeObserver : class {
    func didChange(_ notification: NotificationName, value: String)
}

Arrlindii

class Observer: UIViewController, StateChangeObserver {
    let loginData = LoginData()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        loginData.observer = self
    }
    
    func didChange(_ notification: NotificationName, value: String) {
        if notification == .emailChangeNotification {

Arrlindii

class KeychainService {
    func save(_ password: String, for account: String) {
        let password = password.data(using: String.Encoding.utf8)!
        let query: [String: Any] = [kSecClass as String: kSecClassGenericPassword,
                                    kSecAttrAccount as String: account,
                                    kSecValueData as String: password]
        let status = SecItemAdd(query as CFDictionary, nil)
        guard status == errSecSuccess else { return print("save error")
    }
}