A component that takes multiple masks and automatically updates the textfield based on input's length

SequenceCustomMaskTextfield.swift

//
//  SequenceCustomMaskTextField.swift
//
//  Created by Domene on 02/02/17.
//

import Foundation
import UIKit

@objc protocol SequenceCustomMaskTextFieldDelegate : UITextFieldDelegate{
  @objc optional func sequenceCustomMasktextFieldDidEndEditing(textField: UITextField)
}

/*
 * CustomMaskTextField can be used with a list of masks.
 * e.g:
 *  customMaskTextField.setMasks(['**.**', '***-***', '$$-$$$'])
 *  It will reorder masks by length.
 *
 *  Use $ for digits ($$-$$$$)
 *  Use * for characters [a-zA-Z] (**-****)
 */
class SequenceCustomMaskTextField: MoveMaisTextField, UITextFieldDelegate{
  private var customMask : CustomMask?
  private var currentMaskIndex : Int = 0
  private var maskSequence : [String] = ["$$$-$$","$$.$$"]
  var cleanText : String? {
    get {
      return self.customMask?.cleanText
    }
    set {
      currentMaskIndex = maskSequence.count-1
      customMask?.formattingPattern = maskSequence[currentMaskIndex]
      var newText = customMask!.formatString(string: newValue ?? "")
      if newText.length < maskSequence[currentMaskIndex].length {
        if currentMaskIndex > 0 {
          currentMaskIndex -= 1
          customMask?.formattingPattern = maskSequence[currentMaskIndex]
          newText = customMask!.formatString(string: newValue ?? "")
        }
      }
      self.text = newText
    }
  }
  
  var customDelegate: CustomMaskTextFieldDelegate? = nil
  
  override func awakeFromNib() {
    super.awakeFromNib()
    super.delegate = self
    customMask = CustomMask(formattingPattern: self.maskSequence.first!)
  }
  
  func setMaskSequence(maskSequence: [String]){
    self.maskSequence = sortArrayByLength(array: maskSequence);
    currentMaskIndex = 0
    customMask?.formattingPattern = self.maskSequence[currentMaskIndex];
  }
  
  private func sortArrayByLength(array: [String]) -> Array<String>{
    let sorted =  array.sorted {
      $0.length < $1.length
    }
    return sorted;
  }
  
  // MARK : UITextFieldDelegate
  func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    return shouldChangeCharactersInRange(range: range, replacementString: string)
  }
  
  func shouldChangeCharactersInRange(range: NSRange, replacementString string: String) -> Bool {
    //Check if backspace was pressed
    //Detect backspace
    let char = string.cString(using: String.Encoding.utf8)!
    let isBackSpace = strcmp(char, "\\b")
    
    if (isBackSpace == -92) { //Backspace was pressed
      if(currentMaskIndex > 0){
        if((self.text!.length-1) <= maskSequence[currentMaskIndex-1].length){
          currentMaskIndex -= 1
        }
      }else{
          currentMaskIndex = 0
      }
      
      
      let string = customMask!.formatStringWithRange(range: range, string: string)
      self.customMask!.formattingPattern = self.maskSequence[currentMaskIndex]
      
      
      self.text = customMask!.formatString(string: self.customMask!.finalText!)
      return false
    }
    
    if maskSequence.count > 0 {
      //if text length greater than currentMask length AND currentMask is not the last
      if((self.text!.length+1) > maskSequence[currentMaskIndex].length){
        if(currentMaskIndex < maskSequence.count-1){
          currentMaskIndex += 1
          self.customMask?.formattingPattern = self.maskSequence[currentMaskIndex]
          self.text = customMask!.formatString(string: self.text!+string)
        }
      }else{
        self.text = customMask!.formatStringWithRange(range: range, string: string)
      }
    }else{
      return true
    }
    
    return false
  }
  
  func textFieldDidEndEditing(_ textField: UITextField) {
    self.customDelegate?.customMasktextFieldDidEndEditing?(textField: textField)
  }
}