Android: putting an icon in the top right corner of a collapsingToolbarLayout?

Question

I want to show a collapsing/expanding toolbar layout that has an icon in the top right corner - both in the expanded and collapsed states. The icon shouldn't move at all.

If I use the layout_gravity and write "top" then the icon isn't visible when the layout is collapsed, and if I write "bottom" then the icon doesn't show at the top when the layout is expanded. How can I solve this?

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/rootLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="220dp"
    android:fitsSystemWindows="true"
    >

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsingToolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:collapsedTitleGravity="center"
        app:expandedTitleGravity="bottom|start"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        >

           <ImageView
            android:id="@+id/backgroundImage"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:contentDescription="@null"
            android:scaleType="centerCrop"
            android:fitsSystemWindows="true"
            app:layout_collapseMode="parallax"
            />

        <FrameLayout
            android:id="@+id/shadow"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/black_40percent_opacity"
            />

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:layout_collapseMode="pin"
            />

        <ImageView
            android:id="@+id/iconToShow"
            android:layout_width="56dp"
            android:layout_height="56dp"
            android:src="@drawable/some_drawable"
            android:padding="16dp"
            android:layout_gravity="top|end"
            />

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

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

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

Answer 1

The solution turned out to be adding this line to the ImageView - no other changes were necessary:

app:layout_collapseMode="pin"

So now the entire imageview looks like this:

<ImageView
            android:id="@+id/someImage"
            android:layout_width="56dp"
            android:layout_height="wrap_content"
            android:src="@drawable/someDrawable"
            android:padding="16dp"
            android:layout_gravity="top|end"
            app:layout_collapseMode="pin"
            />