Android content height below collapsing toolbar

I have an app with a navigation drawer and several fragments. The app has a collapsing toolbar, and the fragments have various content. Some of them are static from XML, others are generated in a recyclerview. Some have a FAB, others don't.

My problem is whatever layout I have below the toolbar, the container height is calculated from the collapsed state. When I expand the toolbar, I expect the below container to shrink in height, but instead it's just pushed down, and it becomes a problem, when I want to place a FAB into the bottom right corner. This way the FAB is being pushed out of the screen when I expand the toolbar.

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout 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:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

        <com.google.android.material.appbar.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.google.android.material.appbar.CollapsingToolbarLayout
                android:id="@+id/container"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">

                <View
                    android:id="@+id/collapse"
                    android:layout_width="wrap_content"
                    android:layout_height="256dp"
                    app:layout_collapseMode="parallax" />

                <com.google.android.material.appbar.MaterialToolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:layout_collapseMode="pin" />

            </com.google.android.material.appbar.CollapsingToolbarLayout>

        </com.google.android.material.appbar.AppBarLayout>

        <fragment
            android:id="@+id/nav_host_fragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:defaultNavHost="true"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            app:navGraph="@navigation/mobile_navigation" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/drawer_header"
        app:menu="@menu/drawer" />
</androidx.drawerlayout.widget.DrawerLayout>

So my question is what I should do to force the <fragment> element to fill the remaining place below the appbar and grow or shrink in height instead of partially sliding out of the screen.

Android content height below collapsing toolbar

0 Answers