It’s easy to create a shadow for your views using custom shapes.
The idea it’s that you create the shadow layer as background first and the content layers on top of that.
But you also need to displace the layers in order to create the shadow effect.
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true">
<layer-list>
<item android:left="4dp" android:top="4dp">
<shape>
<solid android:color="#ff58bb52" />
<corners android:radius="30dip"/>
</shape>
</item>
</layer-list>
</item>
<item>
<layer-list>
<!-- SHADOW LAYER -->
<item android:left="4dp" android:top="4dp">
<shape>
<solid android:color="#66000000" />
<corners android:radius="30dip"/>
</shape>
</item>
<!-- CONTENT LAYER -->
<item android:bottom="4dp" android:right="4dp">
<shape>
<solid android:color="#ff58bb52" />
<corners android:radius="30dip"/>
</shape>
</item>
</layer-list>
</item>
</selector>