Sample code showing how to add icons to UITextFields

UITextFiledIcon.swift

   class SignInViewController: UIViewController {
    
    @IBOutlet weak var emailTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!
   
   override func viewDidLoad() {
        super.viewDidLoad()
        
        //set the label font style
        instagramLabel.font = UIFont(name: "Pacifico", size: 50)
        
        let iconWidth = 20;
        let iconHeight = 20;
        
        //Define the imageView
        let imageView = UIImageView();
        let imageEmail = UIImage(named: "ic_email.png");
        imageView.image = imageEmail;
        
        // set frame on image before adding it to the uitextfield
        imageView.frame = CGRect(x: 5, y: 5, width: iconWidth, height: iconHeight)
        emailTextField.leftViewMode = UITextFieldViewMode.Always
        emailTextField.addSubview(imageView)

        let imageViewPassword = UIImageView();
        let imagePassword = UIImage(named: "ic_password.png");
        
        // set frame on image before adding it to the uitextfield
        imageViewPassword.image = imagePassword;
        imageViewPassword.frame = CGRect(x: 5, y: 5, width: iconWidth, height: iconHeight)
        passwordTextField.leftViewMode = UITextFieldViewMode.Always
        passwordTextField.addSubview(imageViewPassword)
        
        //set Padding
        let paddingView = UIView(frame: CGRectMake(0, 0, 25, self.emailTextField.frame.height))
        emailTextField.leftView = paddingView
        
        let emailPaddingView = UIView(frame: CGRectMake(0, 0, 25, self.passwordTextField.frame.height))
        passwordTextField.leftView = emailPaddingView
        
      }
}