KCD/ShipSlotObserver.swift

   1 //
   2 //  ShipSlotObserver.swift
   3 //  KCD
   4 //
   5 //  Created by Hori,Masaki on 2017/12/31.
   6 //  Copyright © 2017年 Hori,Masaki. All rights reserved.
   7 //
   8
   9 import Cocoa
  10
  11 protocol ShipSlotObserverDelegate: class {
  12
  13     func didChangeSlot0()
  14     func didChangeSlot1()
  15     func didChangeSlot2()
  16     func didChangeSlot3()
  17     func didChangeSlot4()
  18 }
  19
  20 class ShipSlotObserver: NSObject {
  21
  22     private enum SlotPosition {
  23         case first
  24         case second
  25         case third
  26         case fourth
  27         case fifth
  28     }
  29
  30     private let ship: Ship
  31
  32     weak var delegate: ShipSlotObserverDelegate?
  33
  34     private var observations: [NSKeyValueObservation] = []
  35
  36     init(ship: Ship) {
  37
  38         self.ship = ship
  39
  40         super.init()
  41
  42         observeSlot()
  43         observeOnSlot()
  44     }
  45
  46     private func observeSlot() {
  47
  48         let keyPaths = [\Ship.slot_0, \Ship.slot_1, \Ship.slot_2, \Ship.slot_3, \Ship.slot_4]
  49         observe(keyPaths: keyPaths)
  50     }
  51
  52     private func observeOnSlot() {
  53
  54         let keyPaths = [\Ship.onslot_0, \Ship.onslot_1, \Ship.onslot_2, \Ship.onslot_3, \Ship.onslot_4]
  55         observe(keyPaths: keyPaths)
  56     }
  57
  58     private func observe(keyPaths: [KeyPath<Ship, Int>]) {
  59
  60         let positions: [SlotPosition] = [.first, .second, .third, .fourth, .fifth]
  61
  62         observations += zip(keyPaths, positions)
  63             .map { [weak self] keyPath, position in
  64                 ship.observe(keyPath) { _, _ in
  65                     self?.notifyChange(on: position)
  66                 }
  67         }
  68     }
  69
  70     private func notifyChange(on position: SlotPosition) {
  71
  72         switch position {
  73
  74         case .first: delegate?.didChangeSlot0()
  75         case .second: delegate?.didChangeSlot1()
  76         case .third: delegate?.didChangeSlot2()
  77         case .fourth: delegate?.didChangeSlot3()
  78         case .fifth: delegate?.didChangeSlot4()
  79         }
  80     }
  81 }