legado/app/src/main/res/layout/activity_rule_sub.xml

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

    <io.legado.app.ui.widget.TitleBar
        android:id="@+id/title_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:title="@string/rule_subscription" />

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            tools:listitem="@layout/item_rule_sub" />

        <TextView
            android:id="@+id/tv_empty_msg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:layout_gravity="center"
            android:gravity="center"
            android:visibility="gone"
            android:text="@string/rule_sub_empty_msg"
            app:layout_constraintTop_toBottomOf="@+id/title_bar"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            tools:text="TextView" />

    </FrameLayout>

</LinearLayout>