ListAdapterを使ったRecyclerViewの使い方について

Question

実現したいこと

ListAdapterを使ったRecyclerViewで複数のViewHolderを使って、Viewの表示を行いたい。

詰まっている点

2種類（ヘッダー、フッター）のViewHolderがあるが、１つ目にlistに追加したデータ（ヘッダー用ビュー）分しか表示されない。ビルドは通っている。

環境

Android Studio 3.3.2
compileSdkVersion 28
targetSdkVersion 28
minSdkVersion 16
recyclerview-v7:28.0.0

コード

package sample.com.recyclerviewtest

import android.content.Context
import android.support.v7.recyclerview.extensions.ListAdapter
import android.support.v7.util.DiffUtil
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView


private val DIFF_CALLBACK = object : DiffUtil.ItemCallback<Any>() {
    override fun areItemsTheSame(oldItem: Any, newItem: Any): Boolean = oldItem == newItem
    override fun areContentsTheSame(oldItem: Any, newItem: Any): Boolean = oldItem == newItem
}
private val dataList: MutableList<Any> = mutableListOf()

class MyAdapter(
    context: Context, data: MutableList<String>
) : ListAdapter<Any, RecyclerView.ViewHolder>(DIFF_CALLBACK) {

    init {
        dataList.add(HeaderData(title = "headerだよ"))
        dataList.add(FooterData(text = "footerだよ"))
        submitList(dataList.toList())
    }

    private val layoutInflater = LayoutInflater.from(context)

    override fun getItemCount(): Int = dataList.size

    override fun getItemViewType(position: Int): Int {
        return when (getItem(position)) {
            is HeaderData -> R.layout.view_header
            is FooterData -> R.layout.view_footer
            else -> throw AssertionError()
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        return when (viewType) {
            R.layout.view_header -> {
                HeaderViewHolder(layoutInflater.inflate(R.layout.view_header, parent, false))
            }
            R.layout.view_footer -> {
                FooterViewHolder(layoutInflater.inflate(R.layout.view_footer, parent, false))
            }
            else -> {
                throw IllegalArgumentException()
            }
        }
    }

    override fun onBindViewHolder(viewHolder: RecyclerView.ViewHolder, position: Int) {
        val item = getItem(position)
        when {
            viewHolder is HeaderViewHolder && item is HeaderData -> {
                viewHolder.bind(item)
            }
            viewHolder is FooterViewHolder && item is FooterData -> {
                viewHolder.bind(item)
            }
        }
    }

    private class HeaderData(
        val title: String
    )

    private inner class HeaderViewHolder(view: View) :
        RecyclerView.ViewHolder(view) {
        val header: TextView = view.findViewById(R.id.header)

        fun bind(data: HeaderData) {
            header.text = data.title
        }
    }

    private class FooterData(
        val text: String
    )

    private inner class FooterViewHolder(view: View) :
        RecyclerView.ViewHolder(view) {
        val footer: TextView = view.findViewById(R.id.footer)

        fun bind(data: FooterData) {
            footer.text = data.text
        }
    }
}

view_header.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools">

    <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        <TextView
                android:id="@+id/header"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"/>
    </android.support.constraint.ConstraintLayout>
</layout>

view_footer.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools">

    <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        <TextView
                android:id="@+id/footer"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"/>
    </android.support.constraint.ConstraintLayout>
</layout>

Answer 1

自己解決しました。
view_header.xmlとview_footer.xmlの不要なConstraintLayoutを削除すると、正常に動きました。