res/layout/directory_header.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2018 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/directory_header"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <com.android.documentsui.HorizontalBreadcrumb
        android:id="@+id/horizontal_breadcrumb"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?android:attr/colorBackground"/>

    <!-- used for search chip. -->
    <include layout="@layout/search_chip_row"/>

    <LinearLayout
        android:id="@+id/tabs_container"
        android:theme="@style/TabTheme"
        android:clipToPadding="true"
        android:clipChildren="true"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingLeft="@dimen/profile_tab_padding"
        android:paddingRight="@dimen/profile_tab_padding"
        android:orientation="vertical">

        <com.google.android.material.tabs.TabLayout
            android:id="@+id/tabs"
            android:background="@android:color/transparent"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMaxWidth="0dp"
            app:tabGravity="fill"
            app:tabMode="fixed"
            app:tabIndicatorColor="?android:attr/colorAccent"
            app:tabIndicatorHeight="@dimen/tab_selector_indicator_height"
            app:tabSelectedTextColor="@color/tab_selected_text_color"
            app:tabTextAppearance="@style/TabTextAppearance"
            app:tabTextColor="@color/tab_unselected_text_color"/>
        <View
            android:id="@+id/tab_separator"
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="?android:attr/listDivider"/>
    </LinearLayout>

    <!-- used for apps row. -->
    <include layout="@layout/apps_row"/>

    <LinearLayout
        android:id="@+id/header_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/root_info_header_horizontal_padding"
        android:layout_marginEnd="@dimen/root_info_header_horizontal_padding"
        android:minHeight="@dimen/root_info_header_height">

        <TextView
            android:id="@+id/header_title"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:textAppearance="@style/SectionHeader"
            android:maxLines="1"
            android:ellipsize="end"
            android:gravity="start|center_vertical"/>

        <androidx.appcompat.widget.ActionMenuView
            android:id="@+id/sub_menu"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="end|center_vertical"/>

    </LinearLayout>

    <!-- column headers are empty on small screens, in portrait or in grid mode. -->
    <include layout="@layout/column_headers"/>

</LinearLayout>