PHV_demo_gallery_advance_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <com.mindorks.placeholderview.PlaceHolderView
        android:id="@+id/galleryView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbars="vertical"/>
</LinearLayout>