java_mot_testing/app/src/main/res/layout/ex9_data_binding.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/button_add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="+"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button_sub"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="-"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button_add" />

    <Button
        android:id="@+id/button_mult"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="*"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button_sub" />

    <Button
        android:id="@+id/button_div"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="/"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.501"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button_mult" />

    <TextView
        android:id="@+id/txt_equals"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="48dp"
        android:text="="
        android:textSize="34sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.183"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button_div" />

    <TextView
        android:id="@+id/txt_denom_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="3dp"
        android:layout_marginBottom="412dp"
        android:inputType="numberSigned"
        android:numeric="integer"
        android:text="TextView"
        android:textAlignment="center"
        android:textSize="34sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.247"
        app:layout_constraintStart_toEndOf="@+id/txt_equals"
        app:layout_constraintTop_toBottomOf="@+id/txt_enum_result" />

    <TextView
        android:id="@+id/txt_enum_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:numeric="integer"
        android:text="TextView"
        android:textAlignment="center"
        android:textSize="34sp"
        app:layout_constraintBottom_toTopOf="@+id/txt_denom_result"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.247"
        app:layout_constraintStart_toEndOf="@+id/txt_equals"
        app:layout_constraintTop_toBottomOf="@+id/button_div" />

    <EditText
        android:id="@+id/enumRight"
        android:layout_width="140dp"
        android:layout_height="50dp"
        android:layout_marginTop="32dp"
        android:ems="10"
        android:hint="Zähler"
        android:inputType="numberSigned"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/button_add"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/enumRight2"
        android:layout_width="140dp"
        android:layout_height="50dp"
        android:layout_marginTop="32dp"
        android:ems="10"
        android:hint="Zähler"
        android:inputType="numberSigned"
        app:layout_constraintEnd_toStartOf="@+id/button_add"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/denomLeft"
        android:layout_width="140dp"
        android:layout_height="50dp"
        android:layout_marginTop="32dp"
        android:ems="10"
        android:hint="Nenner"
        android:inputType="number"
        app:layout_constraintEnd_toStartOf="@+id/button_mult"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/enumRight2" />

    <EditText
        android:id="@+id/denomRight"
        android:layout_width="140dp"
        android:layout_height="50dp"
        android:layout_marginTop="32dp"
        android:ems="10"
        android:hint="Nenner"
        android:inputType="number"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/button_mult"
        app:layout_constraintTop_toBottomOf="@+id/enumRight" />

</androidx.constraintlayout.widget.ConstraintLayout>