apply method

Implementation

@override
TextEditingValue apply(TextEditingValue value) {
  // To stay inline with the plain text model we should follow a last write wins
  // policy and apply the delta to the oldText. This is due to the asynchronous
  // nature of the connection between the framework and platform text input plugins.
  String newText = oldText;
  assert(
    _debugTextRangeIsValid(deletedRange, newText),
    'Applying TextEditingDeltaDeletion failed, the deletedRange: $deletedRange is not within the bounds of $newText of length: ${newText.length}',
  );
  newText = _replace(newText, '', deletedRange);
  assert(
    _debugTextRangeIsValid(selection, newText),
    'Applying TextEditingDeltaDeletion failed, the selection range: $selection is not within the bounds of $newText of length: ${newText.length}',
  );
  assert(
    _debugTextRangeIsValid(composing, newText),
    'Applying TextEditingDeltaDeletion failed, the composing range: $composing is not within the bounds of $newText of length: ${newText.length}',
  );
  return value.copyWith(text: newText, selection: selection, composing: composing);
}