Another approach to EditTexts inside RecyclerView

EditableAdapter.kt

import android.text.Editable
import android.text.SpannableStringBuilder
import android.view.ViewGroup
import android.view.ViewGroup.LayoutParams.MATCH_PARENT
import android.view.ViewGroup.LayoutParams.WRAP_CONTENT
import android.widget.EditText
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.RecyclerView

/**
 * Another approach to EditTexts inside RecyclerView.
 * @author Mike Gorünóv
 */
class EditableAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    private val editables = ArrayList<Editable?>()
    private var strings = emptyList<String>()

    @Suppress("SetterBackingFieldAssignment")
    var items: List<String> =
        object : AbstractList<String>() {
            override val size: Int get() = strings.size
            override fun get(index: Int): String = editables.getOrNull(index)?.toString() ?: strings[index]
        }
        set(value) {
            DiffUtil.calculateDiff(object : DiffUtil.Callback() {
                override fun getOldListSize(): Int = strings.size
                override fun getNewListSize(): Int = value.size
                override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean =
                    (editables.getOrNull(oldItemPosition) ?: strings[oldItemPosition])
                        .contentEquals(value[newItemPosition])
                override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean =
                    areItemsTheSame(oldItemPosition, newItemPosition)
            }).dispatchUpdatesTo(this)
            editables.clear()
            strings = value
            notifyItemRangeChanged(0, strings.size, Unit) // drop and recreate editables for bound views
        }

    override fun getItemCount(): Int =
        strings.size

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder =
        object : RecyclerView.ViewHolder(EditText(parent.context).apply {
            layoutParams = RecyclerView.LayoutParams(MATCH_PARENT, WRAP_CONTENT)
            setEditableFactory(IdentityEditableFactory)
        }) {}

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        (holder.itemView as EditText).text = editables.getOrNull(position)
            ?: SpannableStringBuilder(strings[position]).also {
                while (editables.lastIndex < position) editables.add(null)
                editables[position] = it
            }
    }
    
    private object IdentityEditableFactory : Editable.Factory() {
        override fun newEditable(source: CharSequence): Editable = source as Editable
    }
}