main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:shimmer="http://schemas.android.com/apk/res-auto"
    tools:context="com.example.MainActivity">

    <com.facebook.shimmer.ShimmerFrameLayout
        android:id="@+id/shimmer_view_container"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="15dp"
        android:orientation="vertical">

        <include layout="@layout/shimmer_grid_shadow" />


    </com.facebook.shimmer.ShimmerFrameLayout>

    <GridView
        android:id="@+id/gridVPubs"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:columnWidth="90dp"
        android:paddingBottom="3dp"
        android:paddingTop="3dp"
        android:paddingLeft="3dp"
        android:paddingRight="3dp"
        android:scrollbars="none"
        android:numColumns="auto_fit"
        android:verticalSpacing="10dp"
        android:horizontalSpacing="10dp"
        android:stretchMode="columnWidth"
        android:gravity="center"
        />

    <!--Or you can use FrameLayout instead of Grid/List to show a full Fragment
    
    <FrameLayout
        android:id="@+id/mainContent"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/> -->
    
</android.support.constraint.ConstraintLayout>