Android L's Ripple Effect - Touch Feedback for Buttons - Using XML

UPDATE Material Components:

With the Material Components Library it is very easy to apply a ripple.
Just use the MaterialButton and the app:rippleColor attribute:

<com.google.android.material.button.MaterialButton    app:rippleColor="@color/my_selector"    ../>

With a selector like this:

<selector xmlns:android="http://schemas.android.com/apk/res/android">  <item android:alpha="..." android:color="?attr/colorOnPrimary" android:state_pressed="true"/>  <item android:alpha="..." android:color="?attr/colorOnPrimary" android:state_focused="true" android:state_hovered="true"/>  <item android:alpha="..." android:color="?attr/colorOnPrimary" android:state_focused="true"/>  <item android:alpha="..." android:color="?attr/colorOnPrimary" android:state_hovered="true"/>  <item android:alpha="..." android:color="?attr/colorOnPrimary"/></selector>

Old answer
You can do something like this:

<Button      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:background="@drawable/ripple"          />

Where the ripple.xml is:

<ripple xmlns:android="http://schemas.android.com/apk/res/android"                       android:color="?android:colorControlHighlight">        <item android:id="@android:id/mask">            <shape android:shape="oval">                <solid android:color="?android:colorAccent" />            </shape>        </item> </ripple>

Just put ?attr/selectableItemBackground in the background of button for API 21+ , like below:

<Button        android:layout_width="match_parent"        android:layout_height="70dp"        android:background="?attr/selectableItemBackground"        android:text="Button" />

For lollipop(API>21) make file as btn_ripple_effect.xml in drawable and put below code

<?xml version="1.0" encoding="utf-8"?><ripple xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:color="?android:colorAccent"    tools:targetApi="lollipop">    <item android:drawable="@color/cancel_btn_clr" /> <!-- default -->    <item android:id="@android:id/mask">        <shape android:shape="rectangle">            <solid android:color="?android:colorAccent" />        </shape>    </item></ripple>

For pre lollipop (API<21)make file as btn_ripple_effect.xml in drawable-v21 folder and put below code

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:state_pressed="true">        <shape>            <solid android:color="@color/colorAccent"></solid>        </shape>    </item>    <item>        <shape>            <solid android:color="@color/cancel_btn_clr"></solid>        </shape>    </item></selector>