res/layout/widgets_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2015 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.
-->
<!-- The top and bottom paddings are defined in this container, but since we want
     the list view to span the full width (for touch interception purposes), we
     will bake the left/right padding into that view's background itself. -->
<com.android.launcher3.widget.WidgetsContainerView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:launcher="http://schemas.android.com/apk/res-auto"
    android:id="@+id/widgets_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingTop="@dimen/container_bounds_inset"
    android:paddingBottom="@dimen/container_bounds_inset"
    android:descendantFocusability="afterDescendants"
    launcher:revealBackground="@drawable/quantum_panel_shape_dark"
    android:theme="@style/WidgetContainerTheme">

    <View
        android:id="@+id/reveal_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:focusable="false"
        android:elevation="2dp"
        android:visibility="invisible" />

    <FrameLayout
        android:id="@+id/main_content"
        android:layout_gravity="center"
        android:elevation="15dp"
        android:visibility="gone"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.android.launcher3.widget.WidgetsRecyclerView
            android:id="@+id/widgets_list_view"
            android:theme="@style/CustomOverscroll.Dark"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <ProgressBar
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/loader"
            android:layout_gravity="center" />
    </FrameLayout>


</com.android.launcher3.widget.WidgetsContainerView>