activity_main.xml

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

    <data>
        <variable
            name="user"
            type="com.example.daamjad.databinding.bindingModels.UserModel"/>
        <variable
            name="handlers"
            type="com.example.daamjad.databinding.bindingModels.MyHandlers"/>
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="vertical"
        android:layout_height="wrap_content">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@{user.firstName}"
        android:onClick="@{handlers::onClick}"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    </LinearLayout>
</layout>