formatEditUpdate method

@override TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue)

Called when text is being typed or cut/copy/pasted in the EditableText.

You can override the resulting text based on the previous text value and the incoming new text value.

When formatters are chained, oldValue reflects the initial value of TextEditingValue at the beginning of the chain.

Implementation

@override
TextEditingValue formatEditUpdate(
    TextEditingValue oldValue, TextEditingValue newValue) {
  final text = newValue.text;

  if (text.isEmpty) {
    return newValue;
  }

  // Check if the text is a valid number
  if (!_isValidDecimal(text)) {
    return oldValue;
  }

  // Parse the input value as a double
  double value = double.tryParse(text) ?? 0.0;

  // Remove unnecessary decimals if value is a whole number
  String formatted = value.toStringAsFixed(value.truncateToDouble() == value ? 0 : decimalPlaces);

  if (convertToFloat) {
    return TextEditingValue(
      text: value.toString(), // Convert to float representation
      selection: TextSelection.collapsed(offset: value.toString().length),
    );
  } else {
    return TextEditingValue(
      text: formatted,
      selection: TextSelection.collapsed(offset: formatted.length),
    );
  }
}