You can override when the keyboard disappears using this method:
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK &&
event.getAction() == KeyEvent.ACTION_UP) {
// Do your thing here
return false;
}
return super.dispatchKeyEvent(event);
}
Taken from my other answer @ : Android: Error popup on EditText doesn’t move down when keyboard goes away