Ripple effect example

ripple_attrs.txt

android:clickable="true"
android:focusable="true"
android:foreground="?android:attr/selectableItemBackground"

ripple_sample.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:card_view="http://schemas.android.com/tools">

    <android.support.v7.widget.CardView
        android:id="@+id/cardView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:cardCornerRadius="3dp"
        android:layout_margin="4dp"
        card_view:cardBackgroundColor="@android:color/white"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?android:attr/selectableItemBackground">
        
        <!-- TODO -->
      </android.support.v7.widget.CardView>
</FrameLayout>