title: android format edittext to display spaces after every 4 characters
body: <p>Android - I want to get a number input from the user into an EditText - it needs to be separated by spaces - every 4 characters. 
  Example: 123456781234 -> 1234 5678 1234</p>
  
  <p>This is only for visual purpose. However i need the string without spaces for further usage.</p>
  
  <p>What is the easiest way I can do this?</p>