スクロールで画面外に出た RecyclerView のアイテムを取得してみた件

方法

RecyclerView.Adapter の onViewDetachedFromWindow で検知できます。

サンプル

SampleAdapter.kt

import android.content.Context
import android.databinding.DataBindingUtil
import android.support.v7.widget.RecyclerView
import android.util.Log
import android.view.LayoutInflater
import android.view.ViewGroup
import tokyo.tt.databinding.RecyclerItemSampleBinding

class SampleAdapter(
        context: Context,
        private val texts: List<String>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    companion object {
        val TAG: String = SampleAdapter::class.java.simpleName
    }

    private val layoutInflater = LayoutInflater.from(context)

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        when (holder) {
            is SampleViewHolder -> holder.bind(texts[position])
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        return SampleViewHolder(DataBindingUtil.inflate(layoutInflater, R.layout.recycler_item_sample, parent, false))
    }

    override fun getItemCount() = texts.size

    override fun onViewDetachedFromWindow(holder: RecyclerView.ViewHolder) {
        super.onViewDetachedFromWindow(holder)

        // 画面外に出たアイテムの位置も参照できます
        Log.d(TAG, "adapterPosition = ${holder.adapterPosition}")
    }

    inner class SampleViewHolder(private val binding: RecyclerItemSampleBinding) : RecyclerView.ViewHolder(binding.root) {
        fun bind(text: String) {
            binding.textView.text = text
        }
    }
}