samples-flatfoot/codelabs/lifecycle/app/src/main/res/layout/chrono_activity_databinding.xml

<?xml version="1.0" encoding="utf-8"?><!--
  ~ Copyright 2017, The Android Open Source Project
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~      http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  -->

<layout>

    <data>

        <import type="android.databinding.ObservableField" />

        <variable
            name="elapsedTime"
            type="ObservableField&lt;Long&gt;">

        </variable>
    </data>

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/activity_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        tools:context="com.example.android.persistence.codelab.step_databinding.ChronoDataBindingActivity">

        <TextView
            android:id="@+id/hello_textview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:text="Hello World!" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/hello_textview"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:text="@{String.format(@string/seconds, elapsedTime)}" />

    </RelativeLayout>

</layout>