up

app/src/main/res/menu/book_source.xml

@@ -28,6 +28,9 @@
                 android:title="@string/sort">
 
                 <menu>
+                    <group
+                        android:id="@+id/menu_group_sort"
+                        android:checkableBehavior="single" />
 
                     <item
                         android:id="@+id/sort_manual"

app/src/main/res/menu/search_book.xml

@@ -0,0 +1,15 @@
+<menu 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"
+    tools:context=".view.activity.MainActivity">
+
+    <item
+        android:id="@+id/action_book_source_manage"
+        android:title="@string/book_source_manage"
+        app:showAsAction="never" />
+
+    <group android:id="@+id/source_group">
+
+    </group>
+
+</menu>