Keyboard Layout Model with Swift

gistfile1.swift

enum ShiftKeyType {
  case None
  case Once
  case Always
}

enum PunctuationSwitcherType {
  case More
  case Numeric
}

enum KeyboardSwitcherType {
  case NumericAndPunctuation
  case Alphabet
}

enum FunctionKey {
  case Shift(ShiftKeyType)
  case Delete
  case Return
  case KeyboardTypeSwitcher(KeyboardSwitcherType)
  case InputModeSwitcher
  case PunctuationSwitcher(PunctuationSwitcherType)
}

enum Key {
  case Character(String)
  case Function(FunctionKey)
}

enum KeyboardType {
  case Alphabet
  case NumericAndPunctutation
  case MorePunctutation
}

typealias KeyGroup = [Key]

struct Keyboard {
  
  let type: KeyboardType
  
  let shiftKey: ShiftKeyType
  
  let keyboardSwitcher: KeyboardSwitcherType
  
  let punctuationSwitcher: PunctuationSwitcherType
  
  var keys: [KeyGroup] {
    switch (type) {
    case .Alphabet:
      return [
        _mapStrToKeyGroup("QWERTYUIOP"),
        _mapStrToKeyGroup("ASDFGHJKL"),
        [Key.Function(FunctionKey.Shift(shiftKey))] + _mapStrToKeyGroup("ZXCVBNM") + [Key.Function(FunctionKey.Delete)],
        _lastKeyGroup
      ]
      
    case .NumericAndPunctutation:
      return [
        _mapStrToKeyGroup("1234567890"),
        _mapStrToKeyGroup("-/:;()$&@\""),
        _thirdGroupForNonAlphabetKeyboard,
        _lastKeyGroup
      ]
      
    case .MorePunctutation:
      return [
        _mapStrToKeyGroup("[]{}#%^*+="),
        _mapStrToKeyGroup("_\\|~<>€£¥"),
        _thirdGroupForNonAlphabetKeyboard,
        _lastKeyGroup
      ]
    }
  }
  
  private var _lastKeyGroup: KeyGroup {
    return [
       Key.Function(FunctionKey.KeyboardTypeSwitcher(keyboardSwitcher)),
      Key.Function(FunctionKey.InputModeSwitcher),
      Key.Character(" "),
      Key.Function(FunctionKey.Return)
    ]
  }
  
  private var _thirdGroupForNonAlphabetKeyboard: KeyGroup {
    return [Key.Function(FunctionKey.PunctuationSwitcher(punctuationSwitcher))] +
           _mapStrToKeyGroup(".,?!'") +
           [Key.Function(FunctionKey.Delete)]
  }
  
  private func _mapStrToKeyGroup(str: String) -> KeyGroup {
    return map(str) { Key.Character(String($0)) }
  }
  
}