cant position FrameLayout inside ConstraintLayout

Question

Building main app layout that should have:

1) ConstraintLayout as root - because its new and trending changer of RelativeLayout

2) AppBarLayout with toolbar inside

3) BottomNavigationView at the bottom ofc

4) FAB at bottom right above BNV

5) And FrameLayout - container for my fragments that must be between AppBarLayout and BottomNavigationView.

I cant position my FrameLayout. It appears only match_parent with full device size or 0dp.

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
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/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="@dimen/appbar_padding_top"
        android:theme="@style/AppTheme.AppBarOverlay"
        app:layout_constraintTop_toTopOf="@+id/frame_container">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_weight="1"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/AppTheme.PopupOverlay"
            app:title="@string/app_name">

        </android.support.v7.widget.Toolbar>

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

    <FrameLayout
        android:id="@+id/frame_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        app:layout_constraintTop_toTopOf="parent">

    </FrameLayout>


    <android.support.design.widget.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintBottom_toTopOf="@+id/navigation"
        app:layout_constraintEnd_toEndOf="parent"
        app:srcCompat="@drawable/ic_home_black_24dp" />

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="@color/primary"
        app:elevation="8dp"
        app:itemIconTint="@color/icons"
        app:itemTextColor="@color/icons"
        app:layout_constraintBottom_toBottomOf="@+id/frame_container"
        app:layout_insetEdge="bottom"
        app:menu="@menu/navigation" />

</android.support.constraint.ConstraintLayout>

Answer 1

Set constraintTop and constraintBottom like this:

<FrameLayout
    android:id="@+id/frame_container"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    app:layout_constraintTop_toBottomOf="@+id/appbar"
    app:layout_constraintBottom_toTopOf="@+id/navigation">

And also edit the constraints of the other Views