Can Android RecyclerView contain Non Container Views instead of View Container

Question

So basically RecyclerView inflates item View wrapped in (Layout Holder). E.g. For a RecyclerView the items that are inflated in the adapter are like :

list_item.xml contains below code:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="wrap_content"
    android:layout_width="match_parent">
    <Button
        android:id="@+id/option"
        android:layout_height="50dp"
        android:layout_width="match_parent"
        android:text="TESTING"/>
</LinearLayout>

Can it not be like below code?

<merge xmlns:android="http://schemas.android.com/apk/res/android">
    <Button
        android:id="@+id/option"
        android:layout_height="50dp"
        android:layout_width="match_parent"
        android:text="TESTING"/>
</merge>

Because RecyclerView is Container View that can hold simple non-container views and container views (like LinearLayout etc.) Container Views - View which can hold simple views (TextView, button etc.) as well as container Views (like LinearLayout etc.). Simple Views - can not hold any other view within it.

And during inflation in the adapter, we attach it root:-

final View itemView = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.dialog_locker_open_item, parent, true);

The above give exception.

It should have merged but was getting expectation during inflation.

Answer 1

Each ViewHolder needs to contain one root view (constructor argument of ViewHolder) so RecyclerView can detach and recycle it when needed.

It's not designed to keep track of "multiple non-container views" per item (which would happen if you were inflating with <merge> tag).

Also inflate with attachToParent=true is conceptually wrong and will always fail as RecyclerView.Adapter is not the component responsible for laying out the views in RecyclerView (this is the duty of RecyclerView.LayoutManager).