FossifyGallery/app/src/main/res/layout/activity_media.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/coordinator_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.widget.SwipeRefreshLayout
        android:id="@+id/media_holder"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <GridView
            android:id="@+id/media_grid"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:choiceMode="multipleChoiceModal"
            android:columnWidth="@dimen/medium_tmb_size"
            android:horizontalSpacing="1dp"
            android:numColumns="auto_fit"
            android:stretchMode="columnWidth"
            android:verticalSpacing="1dp"/>

    </android.support.v4.widget.SwipeRefreshLayout>
</android.support.design.widget.CoordinatorLayout>