DiffUtil ichidagi qaysi mexanizm ro'yxatdagi elementning faqat o'zgargan qismlarini yangilashga yordam beradi?

DiffUtil ichida, faqat o‘zgargan element qismlarini yangilash uchun getChangePayload() metodidan foydalaniladi. Bu mexanizm, ob’ektning qaysi maydonlari o‘zgarganligini aniqlashga imkon beradi va bu ma’lumotlarni adapterga yuborib, faqat mos keladigan View qismlarini yangilash, butun elementni emas.

Foydalanish misoli:

class MyDiffCallback : DiffUtil.Callback() {
    override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
        return oldList[oldItemPosition].id == newList[newItemPosition].id
    }

    override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
        return oldList[oldItemPosition] == newList[newItemPosition]
    }

    override fun getChangePayload(oldItemPosition: Int, newItemPosition: Int): Any? {
        val oldItem = oldList[oldItemPosition]
        val newItem = newList[newItemPosition]
        val diffBundle = Bundle()

        if (oldItem.title != newItem.title) {
            diffBundle.putString("KEY_TITLE", newItem.title)
        }
        if (oldItem.description != newItem.description) {
            diffBundle.putString("KEY_DESCRIPTION", newItem.description)
        }

        return if (diffBundle.size() == 0) null else diffBundle
    }
}

Adapterda, onBindViewHolder metodida, bu payloadni ishlatib, faqat o‘zgargan maydonlarni yangilash mumkin, bu esa interfeysning ishlashini va silliqligini yaxshilaydi.