<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"
  android:visibility="visible">

  <androidx.camera.view.PreviewView
    android:id="@+id/preview_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="visible"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

  <Button
    android:id="@+id/capture_button"
    android:layout_width="@dimen/camera_button_size_normal"
    android:layout_height="@dimen/camera_button_size_normal"
    android:layout_marginBottom="16dp"
    android:background="@drawable/camera_button"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent" />

  <Button
    android:id="@+id/flip_button"
    android:layout_width="49dp"
    android:layout_height="49dp"
    android:layout_marginBottom="28dp"
    android:layout_marginRight="28dp"
    android:background="@drawable/ic_baseline_flip_camera_ios_24"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>