formatEditUpdate method

@override TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue)

Formats the text input by allowing only a single space between words.

• If the new input contains only a space, the previous value is retained.
• If a space is entered consecutively, it is ignored.
• Otherwise, the input is updated normally.

Parameters:

• oldValue: The previous text input value.
• newValue: The updated text input value.

Returns: A TextEditingValue that ensures only single spaces are allowed.

Implementation

@override
TextEditingValue formatEditUpdate(
    TextEditingValue oldValue, TextEditingValue newValue) {
  if (newValue.text == ' ') {
    // If only a space is entered, keep the previous value
    return oldValue;
  }

  // Allow a single space only if not preceded by another space
  if (newValue.text == ' ' && _isPreviousSpace) {
    return TextEditingValue(
      text: oldValue.text,
      selection: TextSelection.collapsed(offset: oldValue.text.length),
    );
  }

  // Update the flag based on the last character
  _isPreviousSpace = newValue.text.endsWith(' ');
  return newValue;
}