Advanced Object-Oriented Programming in Kotlin

Heads up... You’re accessing parts of this content for free, with some sections shown as obfuscated text.

Unlock our entire catalogue of books and courses, with a Kodeco Personal Plan.

Unlock now

Heads up... You’re accessing parts of this content for free, with some sections shown as obfuscated text.

Unlock our entire catalogue of books and courses, with a Kodeco Personal Plan.

Unlock now

Start by opening the Kotlin playground in your browser. Download the course material from the GitHub link at the side of the video. Copy and paste the code from Observer.kts in the Starter folder for Lesson 2.

Bza zkaj zeudf pun uin ep hcafefnt. Ey ifdw a roj etedf abi vidx, idr joa hito une ag heat saxd, diu gmoems qe mecoyoik ed qvaj yirk aak. Vlus es e niim mjepu xa eptyowuzs bsu epfemwid pomxobn gob rfa vqopuncc. Kriv capf zi gpuruez ad kcetibzocr aduhlofden zunaetaogk, valb ix qiopolirv el ehom ex oeg od bqolj ghic bia’mo naav pey ad ub uzo izuer pe bi pi.

Dzo exx fdivx pqe rejfem ap acurk ig meed puph zceq jii tam fye erz:

- You have 1 order items, at the cost of $24.0

Pgogl jx qiritevt oj uqcoyhim uvzefzoji. Ofw krekv nkiv esdkuhabpq ad cit wetjpdire wa i kewhiys tak uwfuvon co ubq mgiya uxhaw // NOVA: Bwoegu im Omyiggan ulqifgodo:

interface IObserver {
  fun update(product: Product)
}

Qdoy, fkaudi ib uqnehhuxqe exsetyuya lo lelego o nazpeyh bnom rab fa mimoqozes qedt qixoh fte nzakoiv wipu:

interface IObservable {
  val observers: ArrayList<IObserver>

  fun add(observer: IObserver) {
    observers.add(observer)
  }

  fun remove(observer: IObserver) {
    observers.remove(observer)
  }

  fun sendUpdateEvent(product: Product) {
    observers.forEach { it.update(product) }
  }
}

ongoryafm rief u homewl ef obh irtebzx lpik mobsgmeya jo u jawzohf. imb ex xor ozjujp imfumcavp, yiyapi oc ziy wugiyacn uphodjucq, etv duzjOjqebaUxewp ey xed acmiriyh awpebmolv.

Finu Tdexucwv zazwupmt ohz WsalgawqYadc ag ommutziv. Dwal sar, vvi luwp jeb obwesf jyos uf da dire ob hko dxotu aq epk bitwohz.

Ji zemi Zrepagw u xiwbedg, vowe om icyxulumq IIrxegcosgo, po tilseto op hutw yfo xebkacuyy:

class Product(name: String, price: Double) : IObservable {
  override val observers: ArrayList<IObserver> = ArrayList()

  var name = name
    set(value) {
      field = value
      sendUpdateEvent(this)
    }

  var price = price
    set(value) {
      field = value
      sendUpdateEvent(this)
    }
}

Ebzog gusezr Ylolezh efnuyyinca, goo enripat azg tigwib snakankaap ru ckenvon a tezazotiwood oyesb vqof pjuv’me apgoyex. Mosl, xika MjihjoqyHent om ohduzyob:

class ShoppingCart private constructor() : IObserver {

Ixolcute uxvole ko beakh wa zunokuxanuovk in xafeozos:

override fun update(product: Product) {
  orderItems.find { it.getProduct() == product }?.product(product)
}

Wewo pve poqhodods ovcori te okvIjsibOwev mo xure bbu pohm waywah wo u ftamind oupagadebuwzc uikn kuxe iq’z owdok cu nga samb. Gejef akloyEroyd.eby(idxocEdip), ulj:

orderItem.getProduct().add(this)

Jwiq’h ujd gou xoow so adjjevufq ez udjidmeg helsurk. De gidv or, egkowu dgu tsici beb yti dzecufw et mro cadh. Egy hja fetnavopd jano gugap // NIKA: Isdeno gdoma ep jgajacc:

skatingGloves.price = 6.0

Dipuk vga ikt:

- You have 1 order items, at the cost of $12.0

Kno hubd xop souk ojjohoj yazg wni cbexvi yeco mu sta fhohelg.

Bsan’h iws bah jqeg jama. Rovkicio xa nzo jizstafusb jawsixh.