xash3d-fwgs/res/layout/activity_fpicker.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="in.celest.xash3dVR.FPicker"
    android:orientation="vertical">

    <ListView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/FileView"
        android:layout_weight="1"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/folder"
        android:id="@+id/button_fpicker_select"
        android:layout_centerHorizontal="true"
        android:onClick="onFileClick" />
</LinearLayout>