work/integration-tests/testapp/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 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.
  -->

<android.support.constraint.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"
    tools:context="androidx.work.integration.testapp.MainActivity">

    <Button
        android:id="@+id/enqueue_infinite_work_charging"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="Infinite Work + Charging Constraint"
        app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/clear_all"/>

    <Button
        android:id="@+id/sherlock_holmes"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="12dp"
        android:text="Sherlock Holmes"
        app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/enqueue_infinite_work_network"/>

    <Button
        android:id="@+id/image_processing"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="12dp"
        android:text="Image Processing"
        app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/sherlock_holmes"/>

    <Button
        android:id="@+id/image_uri"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="12dp"
        android:text="Observe Image URI"
        app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/image_processing"/>

    <EditText
        android:id="@+id/delay_in_ms"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="12dp"
        android:ems="10"
        android:hint="Delay in ms"
        android:inputType="number"
        android:singleLine="true"
        android:text="0"
        app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/image_uri"/>

    <Button
        android:id="@+id/schedule_delay"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="12dp"
        android:text="Schedule"
        app:layout_constraintStart_toEndOf="@+id/delay_in_ms"
        app:layout_constraintTop_toBottomOf="@+id/image_uri"/>

    <Button
        android:id="@+id/enqueue_infinite_work_network"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="12dp"
        android:text="Infinite Work + Network Constraint"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/enqueue_infinite_work_charging"/>

</android.support.constraint.ConstraintLayout>