LibreTube/app/src/main/res/layout/dialog_addtoplaylist.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">


    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/app_name"
        android:gravity="center"
        android:layout_margin="10dp"
        android:textSize="20sp" />

    <Spinner
        android:id="@+id/playlists_spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="8dp"
        android:layout_margin="8dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">

        <Button
            android:id="@+id/addToPlaylist"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/addToPlaylist"
            android:textColor="@color/white"
            android:padding="8dp"
            android:layout_margin="8dp" />

    </LinearLayout>

</LinearLayout>