Android Layout: Why does my button always NOT RAISE the ListView?

this is my current LayOut code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:padding="16dp"
    android:background="@drawable/background"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageButton
        android:layout_above="@+id/list_of_messages"
        android:background="@android:color/transparent"
        android:id="@+id/buttonLogOut"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/button_log_out"
        android:paddingLeft="60dp" />
  <ImageButton
        android:background="@android:color/transparent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:src="@drawable/button_Send"
        android:id="@+id/fab"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true" />
    <EditText
        android:layout_toLeftOf="@+id/fab"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Your message"
        android:id="@+id/input" />
    <ListView
        android:background="@android:color/white"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:layout_above="@+id/fab"
        android:divider="@android:color/transparent"
        android:dividerHeight="16dp"
        android:id="@+id/list_of_messages"
        android:layout_marginBottom="16dp" />
</RelativeLayout>

      

        
        
        
      

    

And this is what it looks like: Screenshot

The LogOut button is always under the white part. (I just put a white background to see how much the ListView is covered).

So - it always covers EVERYTHING at the top. However, the "above" part with the submit button and edittext at the bottom of the layout works.

I would need to hover the button on top of the white middle section. Why isn't it working? I usually switch to linear layout, but in this particular example, I cannot do that. In lin layout, I would just add 10/80/10 scales. But it doesn't work here. What am I doing wrong?:/