class ViewModel() {
	fun onClick(v: View) {
		when(v) {
			// …
		}
	}


<?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="viewmodel"
            type=“…ViewModel" />
    </data>

    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

            <Button
                android:id="@+id/button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=“button”
                android:onClick="@{(v) -> viewmodel.onClick(v)}"/>
  
    </androidx.appcompat.widget.LinearLayoutCompat>
</layout>