android_multiviewwer/app/src/main/res/drawable/date_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <shape>
            <solid android:color="@android:color/white"/>
            <corners android:radius="@dimen/base_radius"/>
        </shape>
    </item>
    <item android:state_selected="false">
        <shape>
            <solid android:color="@android:color/transparent"/>
            <corners android:radius="@dimen/base_radius"/>
        </shape>
    </item>
</selector>