Dart APIunself_componentCardTextEditonChanged onChanged property Null safety ValueChanged<String>? onChanged final Implementation final ValueChanged<String>? onChanged; unself_component unself_component CardTextEdit onChanged property CardTextEdit class Constructors CardTextEdit Properties autoFocus hashCode initialText key onChanged onTap runtimeType Methods createElement createState debugDescribeChildren debugFillProperties noSuchMethod toDiagnosticsNode toString toStringDeep toStringShallow toStringShort Operators operator ==