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

    <com.github.chrisbanes.photoview.PhotoView
        android:id="@+id/photoView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerVertical="true"
        android:adjustViewBounds="true"
        android:background="@drawable/checkerboard"
        app:srcCompat="@android:drawable/screen_background_dark" />

</RelativeLayout>