Having round_corners.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<solid android:color="@android:color/transparent"/>
<corners android:radius="15dp" />
<stroke
android:width="1px"
android:color="#000000" />
</shape>
And my_ripple.xml:
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="?android:attr/colorControlHighlight">
<item android:id="@android:id/mask">
<shape android:shape="rectangle">
<solid android:color="#000000" />
<corners android:radius="15dp" />
</shape>
</item>
<item android:drawable="@drawable/round_corners" />
</ripple>
And button:
<Button
android:background="@drawable/my_ripple"
... />
Will result in this:
See this article.