res/layout/activity_photo_picker.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2020 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.
  -->

<!-- CoordinatorLayout is necessary for various components (e.g. Snackbars, and
     BottomSheet) to operate correctly. -->
<androidx.coordinatorlayout.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/photo_picker_base"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/bottom_sheet"
        android:background="@color/picker_background_color"
        android:clipToOutline="true"
        android:orientation="vertical"
        app:behavior_hideable="true"
        app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">

        <ImageView
            android:id="@+id/drag_bar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginBottom="@dimen/picker_drag_margin_bottom"
            android:layout_marginTop="@dimen/picker_drag_margin_top"
            android:scaleType="fitCenter"
            android:src="@drawable/ic_drag"
            android:contentDescription="@null"/>

        <com.android.providers.media.photopicker.ui.SafetyProtectionSectionView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="5dp"
            android:layout_gravity="center" />

        <TextView
            android:id="@+id/privacy_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginHorizontal="@dimen/picker_privacy_text_horizontal_gap"
            android:layout_marginBottom="@dimen/picker_privacy_text_margin_bottom"
            android:layout_marginTop="@dimen/picker_privacy_text_margin_top"
            android:gravity="center_horizontal"
            android:text="@string/picker_privacy_message"
            android:textColor="?android:attr/textColorPrimary"
            android:textSize="@dimen/picker_privacy_text_size"
            style="?android:attr/textAppearanceListItem"/>

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

            <androidx.fragment.app.FragmentContainerView
                android:id="@+id/fragment_container"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:importantForAccessibility="yes"/>

            <com.google.android.material.appbar.AppBarLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="top"
                android:background="@android:color/transparent"
                app:liftOnScroll="true">

                <androidx.appcompat.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:background="@color/picker_background_color"
                    android:importantForAccessibility="yes"
                    android:accessibilityTraversalAfter="@+id/privacy_text"
                    android:accessibilityTraversalBefore="@+id/fragment_container"
                    app:titleTextColor="?attr/pickerTextColor"
                    app:titleTextAppearance="@style/PickerToolbarTitleTextAppearance">

                    <com.google.android.material.tabs.TabLayout
                        android:id="@+id/tab_layout"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:background="@color/picker_background_color"
                        android:layout_gravity="center"
                        app:tabBackground="@drawable/picker_tab_background"
                        app:tabIndicatorAnimationMode="linear"
                        app:tabIndicatorColor="?attr/pickerSelectedTabBackgroundColor"
                        app:tabIndicatorGravity="center"
                        app:tabMinWidth="@dimen/picker_tab_min_width"
                        app:tabPaddingStart="@dimen/picker_tab_horizontal_gap"
                        app:tabPaddingEnd="@dimen/picker_tab_horizontal_gap"
                        app:tabRippleColor="@null"
                        app:tabSelectedTextColor="?attr/pickerSelectedTabTextColor"
                        app:tabTextAppearance="@style/PickerTabTextAppearance"
                        app:tabTextColor="?android:attr/textColorSecondary" />

                </androidx.appcompat.widget.Toolbar>

            </com.google.android.material.appbar.AppBarLayout>

            <LinearLayout
                android:id="@+id/picker_bottom_bar"
                android:layout_width="match_parent"
                android:layout_height="@dimen/picker_bottom_bar_size"
                android:layout_gravity="bottom"
                android:background="@color/picker_background_color"
                android:elevation="@dimen/picker_bottom_bar_elevation"
                android:visibility="gone"
                android:orientation="horizontal">

                <com.google.android.material.button.MaterialButton
                    android:id="@+id/button_view_selected"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_weight="2"
                    android:layout_marginHorizontal="@dimen/picker_bottom_bar_horizontal_gap"
                    android:gravity="start|center_vertical"
                    android:paddingVertical="@dimen/picker_bottom_bar_buttons_vertical_gap"
                    android:text="@string/picker_view_selected"
                    android:textAllCaps="false"
                    android:textColor="?attr/pickerSelectedColor"
                    android:maxLines="1"
                    android:ellipsize="end"
                    app:icon="@drawable/ic_collections"
                    app:iconPadding="@dimen/picker_viewselected_icon_padding"
                    app:iconSize="@dimen/picker_viewselected_icon_size"
                    app:iconTint="?attr/pickerSelectedColor"
                    app:iconGravity="textStart"
                    style="@style/MaterialBorderlessButtonStyle"/>

                    <Button
                        android:id="@+id/button_add"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:layout_weight="1"
                        android:layout_marginHorizontal="@dimen/picker_bottom_bar_horizontal_gap"
                        android:gravity="center|center_vertical"
                        android:paddingVertical="@dimen/picker_bottom_bar_buttons_vertical_gap"
                        android:text="@string/add"
                        android:textAllCaps="false"
                        android:textColor="?attr/pickerHighlightTextColor"
                        android:maxLines="1"
                        android:ellipsize="middle"
                        android:backgroundTint="?attr/pickerHighlightColor"
                        style="@style/MaterialButtonStyle"/>

                </LinearLayout>

        </FrameLayout>

    </LinearLayout>

    <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
        android:id="@+id/profile_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="@dimen/picker_profile_button_margin_bottom"
        android:layout_gravity="bottom|center"
        android:textAppearance="@style/PickerButtonTextAppearance"
        android:textColor="?attr/pickerProfileButtonTextColor"
        android:text="@string/picker_work_profile"
        android:visibility="gone"
        android:accessibilityTraversalAfter="@+id/toolbar"
        android:accessibilityTraversalBefore="@+id/fragment_container"
        app:backgroundTint="?attr/pickerProfileButtonColor"
        app:borderWidth="0dp"
        app:elevation="3dp"
        app:icon="@drawable/ic_work_outline"/>

    <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
        android:id="@+id/profile_menu_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="@dimen/picker_profile_button_margin_bottom"
        android:layout_gravity="bottom|center"
        android:textAppearance="@style/PickerButtonTextAppearance"
        android:textColor="?attr/pickerProfileButtonTextColor"
        android:visibility="gone"
        android:accessibilityTraversalAfter="@+id/toolbar"
        android:accessibilityTraversalBefore="@+id/fragment_container"
        app:backgroundTint="?attr/pickerProfileButtonColor"
        app:borderWidth="0dp"
        app:elevation="3dp"/>

</androidx.coordinatorlayout.widget.CoordinatorLayout>