formatEditUpdate method

  1. @override
TextEditingValue formatEditUpdate(
  1. TextEditingValue oldValue,
  2. TextEditingValue newValue
)
override

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,
) {
  if (newValue.text.isEmpty) {
    return newValue;
  }

  // Parse the input as an integer
  final num? value = num.tryParse(newValue.text);

  // If the value is not an integer or exceeds the maxValue,
  // return the old value
  if (value == null || maxValue == null) {
    return oldValue;
  } else if (maxValue != null && value > maxValue!) {
    return TextEditingValue(text: maxValue.toString());
  }

  // Otherwise, return the new value
  return newValue;
}