设置重力和textwatcher时，Android EditText不会更改文本

Question

我在自定义布局中使用许多内部EditText，当我单独设置重力并且它有一个TextWatcher时，值不会改变。

public PinFieldView(Context context) {
    super(context);
    init();
}

private void init() {
    setText(defaultValue);
    setTextColor(Color.GRAY);
    setCursorVisible(false);
    setOnFocusChangeListener(focusListener);
    addTextChangedListener(textWatcher);
    setGravity(Gravity.CENTER_HORIZONTAL);
}

private final TextWatcher textWatcher = new TextWatcher() {
    ...

    @Override 
    public void onTextChanged(CharSequence s, int start, int before, int count) {
      removeTextChangedListener(textWatcher);
      if (s.length() == 0) {
        setText(defaultValue);
      } else {
        setText(String.valueOf(s.charAt(s.length() - 1)));
      }
      if (numberChangeListener != null) numberChangeListener.onNumberChanged(getText().toString());
      addTextChangedListener(textWatcher);
    }

    ...
};

不确定是什么问题，我在Android 5.0上测试