title: View.setEnabled(false) does not work quite right in android
body: <p>I just found out View.setEnabled(false) does not work quite right in android, in the following ways:</p>
  
  <ol>
  <li>Disable parent view does not automatically disable child views. This is inconvenient.</li>
  <li>Though grayed in color, disabled views can still get focus and get keyboard input, make choice, etc. This is not right.</li>
  <li>When getting keyboard input, DEL/BACK can only remove one key backward no matter how many you input. This behavior only shows in disabled EditText.</li>
  <li>Radio label is grayed but radio button image is not grayed.</li>
  </ol>
  
  <p>It seems like a bug. But how do I get a real DISABLE feature?</p>
  
  <p>EDIT: forget to mention the first.</p>