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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:id="@+id/reader_menu"
    android:visibility="gone"
    tools:visibility="visible">

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/reader_menu_bottom"
        android:background="@color/reader_menu_background"
        android:orientation="vertical"
        android:layout_alignParentBottom="true">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <TextView
                android:id="@+id/current_page"
                android:layout_width="32dp"
                android:layout_height="wrap_content"
                android:layout_marginLeft="8dp"
                android:layout_gravity="center_vertical"
                android:textColor="@color/light_grey"
                android:gravity="center_horizontal"
                android:layout_marginTop="12dp"
                android:layout_marginBottom="12dp" />

            <SeekBar
                android:id="@+id/page_seeker"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:layout_gravity="center_vertical" />

            <TextView
                android:id="@+id/total_pages"
                android:layout_width="32dp"
                android:layout_height="wrap_content"
                android:layout_marginRight="8dp"
                android:layout_gravity="center_vertical"
                android:textColor="@color/light_grey"
                android:gravity="center_horizontal" />

        </LinearLayout>

        <View android:background="#777777"
            android:layout_width="match_parent"
            android:layout_height="1dp" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">

            <ImageButton
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/lock_orientation"
                android:src="@drawable/ic_screen_rotation"
                android:background="?android:selectableItemBackground" />
            <ImageButton
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:background="?android:selectableItemBackground" />
            <ImageButton
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/reader_selector"
                android:src="@drawable/ic_view_carousel"
                android:background="?android:selectableItemBackground" />
            <ImageButton
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/reader_extra_settings"
                android:src="@drawable/ic_more_vert"
                android:background="?android:selectableItemBackground" />

        </LinearLayout>

    </LinearLayout>

</RelativeLayout>