onSubmitted property Null safety
Called when the user indicates that they are done editing the text in the field.
By default, onSubmitted is called after onChanged when the user has finalized editing; or, if the default behavior has been overridden, after onEditingComplete. See onEditingComplete for details.
- TextInputAction.next and TextInputAction.previous, which automatically shift the focus to the next/previous focusable item when the user is done editing.
final ValueChanged<String>? onSubmitted;