layout.axml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:p1="http://schemas.android.com/apk/res/android"
    p1:background="@android:color/white"
    p1:layout_width="fill_parent"
    p1:layout_height="fill_parent">
    <!-- ... some stuff here, but there's plenty of space -->
    <LinearLayout
        p1:orientation="vertical"
        p1:id="@+id/ListWrapper"
        p1:minWidth="25px"
        p1:minHeight="25px"
        p1:layout_width="fill_parent"
        p1:layout_height="wrap_content"
        p1:layout_marginTop="300dp"
        p1:background="@color/green">
        <Button
            p1:text="Show List"
            p1:id="@+id/btnToggleParkingList"
            p1:background="@android:color/white"
            p1:textColor="@color/normal_text"
            p1:layout_width="fill_parent"
            p1:layout_height="wrap_content" />
        <ListView
            p1:minWidth="25px"
            p1:minHeight="25px"
            p1:layout_width="wrap_content"
            p1:layout_height="wrap_content"
            p1:id="@+id/ParkingList" />
    </LinearLayout>
</RelativeLayout>