res/drawable/bg_celllayout.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
/*
**
** Copyright 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.
*/
-->

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_active="true" >
        <shape android:shape="rectangle" >
            <stroke
                android:width="@dimen/spring_loaded_panel_border"
                android:color="?attr/workspaceAccentColor" />
            <solid android:color="@color/cell_layout_bg_color"/>
            <corners android:radius="@dimen/bg_round_rect_radius" />

        </shape>
    </item>
    <item>
        <shape android:shape="rectangle" >
            <solid android:color="@color/cell_layout_bg_color"/>
            <corners android:radius="@dimen/bg_round_rect_radius" />
        </shape>
    </item>
</selector>