Floating Action Button not showing up on top

Question

I'm currently trying to make a floating action button, however for some reason it keeps rendering the button under my recylerView. I have tried messing with the layout order, elevation, and I even tried using the .bringToFront() method in the java code.

Activity_main

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:id="@+id/drawer"
    android:layout_width="match_parent" android:fitsSystemWindows="true"
    android:layout_height="match_parent">

    <RelativeLayout android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <include android:id="@+id/toolbar_actionbar"
            layout="@layout/toolbar_default"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <include
            android:id="@+id/fab_layout"
            layout="@layout/fab_layout"
            android:layout_width="@dimen/fab_button_diameter"
            android:layout_height="@dimen/fab_button_diameter"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true" />

        <FrameLayout android:id="@+id/container"
           android:layout_width="match_parent"
           android:clickable="true" android:layout_height="match_parent"
           android:layout_below="@+id/toolbar_actionbar">

        <android.support.v7.widget.RecyclerView
           android:id="@+id/cardList"
           android:layout_width="match_parent"
           android:layout_height="match_parent" />

    </FrameLayout>

</RelativeLayout>

<!-- android:layout_marginTop="?android:attr/actionBarSize"-->
<com.android.expresso.expresso.ScrimInsetsFrameLayout android:id="@+id/scrimInsetsFrameLayout"
    android:layout_width="@dimen/navigation_drawer_width"
    android:layout_height="wrap_content"
    android:fitsSystemWindows="true"
    android:layout_gravity="start"
    app:insetForeground="#4000"
    android:elevation="10dp">
    <fragment android:id="@+id/fragment_drawer"
        android:name="com.android.expresso.expresso.NavigationDrawerFragment"
        android:layout_width="@dimen/navigation_drawer_width"
        android:layout_height="match_parent" android:fitsSystemWindows="true"
        app:layout="@layout/fragment_navigation_drawer" />
</com.android.expresso.expresso.ScrimInsetsFrameLayout>

Fab_layout

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

    <ImageButton
        android:id="@+id/fab_image_button"
        android:layout_width="@dimen/fab_button_diameter"
        android:layout_height="@dimen/fab_button_diameter"
        android:background="@drawable/fab_shape"
        android:src="@drawable/btn_order_hub"/>

</FrameLayout>

Answer 1

fab_layout should be last view in xml. drawing is in order of xml - you are drawing FAB and after that other Views (container), they are covering FAB

<RelativeLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <include android:id="@+id/toolbar_actionbar"
        layout="@layout/toolbar_default"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <FrameLayout android:id="@+id/container"
       android:layout_width="match_parent"
       android:clickable="true" android:layout_height="match_parent"
       android:layout_below="@+id/toolbar_actionbar">

        <android.support.v7.widget.RecyclerView
           android:id="@+id/cardList"
           android:layout_width="match_parent"
           android:layout_height="match_parent" />

        <include
            android:id="@+id/fab_layout"
            layout="@layout/fab_layout"
            android:layout_width="@dimen/fab_button_diameter"
            android:layout_height="@dimen/fab_button_diameter"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true" />

    </FrameLayout>
</RelativeLayout>