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
  24         case first
  25
  26         case second
  27
  28         case third
  29
  30         case fourth
  31
  32         case fifth
  33     }
  34
  35     private let ship: Ship
  36
  37     weak var delegate: ShipSlotObserverDelegate?
  38
  39     private var observations: [NSKeyValueObservation] = []
  40
  41     init(ship: Ship) {
  42
  43         self.ship = ship
  44
  45         super.init()
  46
  47         observeSlot()
  48         observeOnSlot()
  49     }
  50
  51     private func observeSlot() {
  52
  53         let keyPaths = [\Ship.slot_0, \Ship.slot_1, \Ship.slot_2, \Ship.slot_3, \Ship.slot_4]
  54         observe(keyPaths: keyPaths)
  55     }
  56
  57     private func observeOnSlot() {
  58
  59         let keyPaths = [\Ship.onslot_0, \Ship.onslot_1, \Ship.onslot_2, \Ship.onslot_3, \Ship.onslot_4]
  60         observe(keyPaths: keyPaths)
  61     }
  62
  63     private func observe(keyPaths: [KeyPath<Ship, Int>]) {
  64
  65         let positions: [SlotPosition] = [.first, .second, .third, .fourth, .fifth]
  66
  67         observations += zip(keyPaths, positions)
  68             .map { [weak self] keyPath, position in
  69
  70                 ship.observe(keyPath) { _, _ in
  71
  72                     self?.notifyChange(on: position)
  73                 }
  74         }
  75     }
  76
  77     private func notifyChange(on position: SlotPosition) {
  78
  79         switch position {
  80
  81         case .first: delegate?.didChangeSlot0()
  82
  83         case .second: delegate?.didChangeSlot1()
  84
  85         case .third: delegate?.didChangeSlot2()
  86
  87         case .fourth: delegate?.didChangeSlot3()
  88
  89         case .fifth: delegate?.didChangeSlot4()
  90
  91         }
  92     }
  93 }