Avoid FAB appear above CoordinatorLayout

I'm trying to put an image on the top of CoordinatorLayout, so it will be half top of the view. it's work fine (attached pic), but when the coordinatorLayout is open to top - the image is get into the coordinatorLayout.
any idea how can i avoid this and keep the image on the top.
i want the image will get into the background zone.

<?xml version="1.0" encoding="utf-8"?>


<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

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

<LinearLayout
android:id="@+id/backgroundLayout"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@color/TRY3"
android:orientation="vertical"></LinearLayout>

<android.support.design.widget.CoordinatorLayout
android:id="@+id/coordinateMainLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="50dp">

<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/TRY3"
android:fitsSystemWindows="true"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsingToolBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
app:expandedTitleTextAppearance="@android:color/transparent"
app:layout_scrollFlags="scroll|exitUntilCollapsed">

</android.support.design.widget.CollapsingToolbarLayout>


</android.support.design.widget.AppBarLayout>

<android.support.v4.widget.NestedScrollView
android:id="@+id/innerScrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clipToPadding="false"
app:layout_behavior="@string/appbar_scrolling_view_behavior">

<RelativeLayout
android:id="@+id/mainLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/B1"
android:orientation="vertical">

<FrameLayout
android:id="@+id/whiteLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/B1">

</FrameLayout>

</RelativeLayout>
</android.support.v4.widget.NestedScrollView>

<android.support.design.widget.FloatingActionButton
android:id="@+id/floatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="70dp"
android:layout_marginLeft="50dp"
android:scaleType="center"
android:src="@drawable/white_plus"
app:backgroundTint="@color/T103"
app:fabSize="normal"
app:layout_anchor="@id/innerScrollView" />
</android.support.design.widget.CoordinatorLayout>

</RelativeLayout>

</android.support.constraint.ConstraintLayout>


a

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.