cat_textfield_exposed_dropdown_menu_content.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright 2019 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
  ~
  ~     https://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:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">


  <com.google.android.material.textfield.TextInputLayout
      style="?attr/textInputFilledExposedDropdownMenuStyle"
      android:layout_width="@dimen/material_textinput_default_width"
      android:layout_height="wrap_content"
      android:layout_margin="4dp"
      android:layout_gravity="center_horizontal"
      android:hint="@string/cat_textfield_label"
      app:errorEnabled="true"
      app:helperText="@string/cat_textfield_filled_exposed_dropdown_helper_text"
      app:helperTextEnabled="true">
    <AutoCompleteTextView
        android:id="@+id/filled_exposed_dropdown"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="none"
        app:simpleItems="@array/cat_textfield_exposed_dropdown_content"/>
  </com.google.android.material.textfield.TextInputLayout>


  <com.google.android.material.textfield.TextInputLayout
    style="?attr/textInputFilledExposedDropdownMenuStyle"
      android:layout_width="@dimen/material_textinput_default_width"
      android:layout_height="wrap_content"
      android:layout_margin="4dp"
      android:layout_gravity="center_horizontal"
      android:hint="@string/cat_textfield_label"
      app:errorEnabled="true"
      app:helperText="@string/cat_textfield_filled_editable_exposed_dropdown_helper_text"
      app:helperTextEnabled="true">
    <AutoCompleteTextView
        android:id="@+id/filled_exposed_dropdown_editable"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:simpleItems="@array/cat_textfield_exposed_dropdown_content"/>
  </com.google.android.material.textfield.TextInputLayout>

  <com.google.android.material.textfield.TextInputLayout
      style="?attr/textInputOutlinedExposedDropdownMenuStyle"
      android:layout_width="@dimen/material_textinput_default_width"
      android:layout_height="wrap_content"
      android:layout_margin="4dp"
      android:layout_gravity="center_horizontal"
      android:hint="@string/cat_textfield_label"
      app:errorEnabled="true"
      app:helperText="@string/cat_textfield_outlined_exposed_dropdown_helper_text"
      app:helperTextEnabled="true">
    <AutoCompleteTextView
        android:id="@+id/outlined_exposed_dropdown"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="none"
        app:simpleItems="@array/cat_textfield_exposed_dropdown_content"/>
  </com.google.android.material.textfield.TextInputLayout>


  <com.google.android.material.textfield.TextInputLayout
      style="?attr/textInputOutlinedExposedDropdownMenuStyle"
      android:layout_width="@dimen/material_textinput_default_width"
      android:layout_height="wrap_content"
      android:layout_margin="4dp"
      android:layout_gravity="center_horizontal"
      android:hint="@string/cat_textfield_label"
      app:errorEnabled="true"
      app:helperText="@string/cat_textfield_outlined_editable_exposed_dropdown_helper_text"
      app:helperTextEnabled="true">
    <AutoCompleteTextView
        android:id="@+id/outlined_exposed_dropdown_editable"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:simpleItems="@array/cat_textfield_exposed_dropdown_content"/>
  </com.google.android.material.textfield.TextInputLayout>

</LinearLayout>