Question

In my app, the user has to enter a phone number in an EditText field using the following format:

1(515)555-5555

I don’t want the user to type “(“, “)”, or “-” while entering the number; I want these characters to be added automatically.

For example, suppose the user typed 1 — the parenthesis after “1” should be added automatically, so that “1(” would be displayed. And I would like to have similar functionality while deleting.

I have tried to set text in the afterTextChanged method of onTextWatcher interface, but it is not working; instead it’s causing an error. Any help will be greatly appreciated.

Answer 1

You’re probably running into a problem because afterTextChanged is re-entrant, i.e. changes made to the text cause the method to be called again.

If that’s the problem, one way way around is to keep an instance variable flag:

public class MyTextWatcher implements TextWatcher {
    private boolean isInAfterTextChanged;

    public synchronized void afterTextChanged(Editable text) {
       if (!isInAfterTextChanged) {
           isInAfterTextChanged = true;

           // TODO format code goes here

           isInAfterTextChanged = false;
       }
    }
}

As an alternative, you could just use PhoneNumberFormattingTextWatcher — it doesn’t do the formatting that you described, but then again you don’t have to do much to use it.