Используйте это ...
edittext_id.addTextChangedListener (new TextWatcher () {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// TODO Auto-generated method stub
//This method will call when you type somthing on edittext
set visibility of your buttons here.
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});