activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <import type="android.view.View"/>
        <variable
            name="cmdHandlers"
            type="com.mwb.digitalstorage.command_handlers.generic_item.ItemOverViewCmdHandler"/>
        <variable
            name="vm"
            type="com.mwb.digitalstorage.viewmodel.MainViewModel"/>
        <variable
            name="vmTb"
            type="com.mwb.digitalstorage.viewmodel.ToolbarViewModel"/>
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:bind="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        tools:context=".MainActivity"
        style="@style/constraint_layout">

        <include
            android="@+id/toolbar"
            layout="@layout/activity_toolbar"
            bind:vmTb="@{vmTb}" />

        <TextView
            android:id="@+id/storages"
            style="@style/layout_titles"
            android:text="Storage units"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            android:layout_marginTop="80dp" />
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rv_storage_units"
            style="@style/recycler_view_storages"
            app:layout_constraintTop_toBottomOf="@id/storages"
            android:layout_height="140dp"
            android:layout_marginTop="15dp"
            tools:listitem="@layout/storage_item" />
        <TextView
            android:id="@+id/txt_no_units"
            style="@style/layout_titles"
            app:layout_constraintTop_toTopOf="@+id/rv_storage_units"
            app:layout_constraintLeft_toLeftOf="@+id/rv_storage_units"
            app:layout_constraintBottom_toBottomOf="@+id/rv_storage_units"
            app:layout_constraintRight_toRightOf="@+id/rv_storage_units"
            android:text="No storage units set"
            android:visibility="@{vm.storageUnits != null ? View.VISIBLE : View.GONE}" />
        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/FABStorage"
            style="@style/floating_button"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/rv_storage_units"
            android:layout_marginRight="20dp"
            android:layout_marginTop="10dp"
            android:onClick="@{(view) -> cmdHandlers.openAddItemMenu()}"/>
        <View
            android:id="@+id/hr"
            style="@style/hr_white"
            app:layout_constraintTop_toBottomOf="@+id/FABStorage" />
        <TextView
            android:id="@+id/orders"
            style="@style/layout_titles"
            android:text="Orders"
            app:layout_constraintTop_toBottomOf="@+id/hr"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            android:layout_marginTop="10dp" />
        <Button
            android:id="@+id/buttonA"
            style="@style/btn_dash"
            android:text="Incoming"
            app:layout_constraintRight_toRightOf="@+id/orders"
            app:layout_constraintTop_toBottomOf="@+id/orders"
            app:layout_constraintLeft_toLeftOf="parent"
            android:layout_marginTop="20dp" />
        <Button
            android:id="@+id/buttonB"
            style="@style/btn_dash"
            android:text="Outgoing"
            app:layout_constraintTop_toTopOf="@+id/buttonA"
            app:layout_constraintLeft_toLeftOf="@+id/orders"
            app:layout_constraintRight_toRightOf="parent" />
        <View
            android:id="@+id/hr2"
            style="@style/hr_white"
            android:layout_marginTop="30dp"
            app:layout_constraintTop_toBottomOf="@+id/buttonA" />
        <TextView
            android:id="@+id/tools"
            style="@style/layout_titles"
            android:text="Tools"
            app:layout_constraintTop_toBottomOf="@+id/hr2"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            android:layout_marginTop="20dp" />
        <Button
            android:id="@+id/buttonC"
            style="@style/btn_dash"
            android:text="Available"
            app:layout_constraintRight_toRightOf="@+id/tools"
            app:layout_constraintTop_toBottomOf="@+id/tools"
            app:layout_constraintLeft_toLeftOf="parent"
            android:layout_marginTop="20dp" />
        <Button
            android:id="@+id/buttonD"
            style="@style/btn_dash"
            android:text="Lent"
            app:layout_constraintTop_toTopOf="@+id/buttonC"
            app:layout_constraintLeft_toLeftOf="@+id/tools"
            app:layout_constraintRight_toRightOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>