Dart APIunself_componentTextAreaautofocus autofocus property Null safety bool? autofocus final Implementation final bool? autofocus; unself_component unself_component TextArea autofocus property TextArea class Constructors TextArea Properties autofocus controller hashCode key onChanged onTap runtimeType Methods build createElement debugDescribeChildren debugFillProperties noSuchMethod toDiagnosticsNode toString toStringDeep toStringShallow toStringShort Operators operator ==