tachiyomi/app/src/main/res/layout/browse_source_controller.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:id="@+id/source_layout"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:id="@+id/catalogue_view"
        tools:context="eu.kanade.tachiyomi.ui.source.browse.BrowseSourceController">

        <ProgressBar
            android:id="@+id/progress"
            style="?android:attr/progressBarStyleLarge"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="center_vertical|center_horizontal"
            android:visibility="gone"/>

    </LinearLayout>
    
    <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
        android:id="@+id/fab"
        style="@style/Theme.Widget.FAB"
        android:text="@string/filter"
        app:icon="@drawable/ic_filter_list_white_24dp"/>

</androidx.coordinatorlayout.widget.CoordinatorLayout>