1. Create the activity_rich_notification.xml file. This is the basic layout.

   <?xml version="1.0" encoding="utf-8"?>
   <android.support.design.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:layout_width="match_parent"
                                                    android:layout_height="wrap_content"
                                                    android:fitsSystemWindows="true"
                                                    tools:context="com.samsung.android.myfirstrichnotification.RichNotificationActivity">
   
      <android.support.design.widget.AppBarLayout android:layout_width="match_parent"
                                                  android:layout_height="wrap_content"
                                                  android:theme="@style/AppTheme.AppBarOverlay">
   
         <android.support.v7.widget.Toolbar android:id="@+id/toolbar"
                                            android:layout_width="match_parent"
                                            android:layout_height="?attr/actionBarSize"
                                            android:background="?attr/colorPrimary"
                                            app:popupTheme="@style/AppTheme.PopupOverlay" />
   
      </android.support.design.widget.AppBarLayout>
   
      <android.support.v4.widget.NestedScrollView android:layout_width="match_parent"
                                                  android:layout_height="match_parent"
                                                  app:layout_behavior="@string/appbar_scrolling_view_behavior">
         <include layout="@layout/content_rich_notification" />
      </android.support.v4.widget.NestedScrollView>
   
   </android.support.design.widget.CoordinatorLayout>
   

2. Create the content_rich_notification.xml file.

   It is possible that the “cannot resolve symbol” appears at this stage. This issue is resolved after the next step as you define the necessary strings.

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                 android:layout_width="fill_parent"
                 android:layout_height="fill_parent"
                 android:orientation="vertical" >
   
      <Spinner android:id="@+id/spinner1"
               android:layout_width="match_parent"
               android:layout_height="wrap_content"
               android:entries="@array/template_arrays"
               android:prompt="@string/template_prompt" />
   
      <Button android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:onClick="onSendClick"
              android:text="@string/send" />
   
   </LinearLayout>
   

The template_arrays in the spinner item have 6 different selectable values. These values are Small Header, Medium Header, Large Header, Full Header, Event, and Image.

<resources>
   <string name="app_name">MyFirstRichNotification</string>
   <string name="action_settings">Settings</string>

   <string name="template_prompt">Choose a template</string>
   <string-array name="template_arrays">
      <item>Small Header</item>
      <item>Medium Header</item>
      <item>Large Header</item>
      <item>Full Header</item>
      <item>Event</item>
      <item>Image</item>
   </string-array>

   <string name="send">Send</string>
   <string name="title_activity_my_callback">MyCallbackActivity</string>

</resources>