Android Buton Efekti

<Button 
                  android:id="@+id/button1" 
                  style="@style/effect" 
                  android:layout_width="match_parent" 
                  android:layout_height="100dp" 
                  android:background="#F7CA18" 
                  android:text="SPARTACUS" 
                  android:textColor="#fff" 
                  android:textSize="30sp" 
                  android:typeface="normal" />

<?xml version="1.0" encoding="utf-8"?> 
  <selector xmlns:android="http://schemas.android.com/apk/res/android"> 
      <item 
          android:state_pressed="true" 
          android:state_enabled="true" 
          android:drawable="@drawable/button_pressed" /> 
      <item 
          android:state_focused="true" 
          android:state_enabled="true" 
          android:drawable="@drawable/button_focused" /> 
      <item 
          android:state_enabled="true" 
          android:drawable="@drawable/button_enabled" /> 
  </selector>