RawKeyboardListener constructor

const RawKeyboardListener({Key key, @required FocusNode focusNode, @required ValueChanged<RawKeyEvent> onKey, @required Widget child })

Creates a widget that receives raw keyboard events.

For text entry, consider using a EditableText, which integrates with on-screen keyboards and input method editors (IMEs).

Implementation 

const RawKeyboardListener({
  Key key,
  @required this.focusNode,
  @required this.onKey,
  @required this.child,
}) : assert(focusNode != null),
     assert(child != null),
     super(key: key);