Listener({Key key, PointerDownEventListener onPointerDown, PointerMoveEventListener onPointerMove, PointerUpEventListener onPointerUp, PointerCancelEventListener onPointerCancel, HitTestBehavior behavior: HitTestBehavior.deferToChild, Widget child })

Creates a widget that forwards point events to callbacks.

The behavior argument defaults to HitTestBehavior.deferToChild.

Source 

Listener({
  Key key,
  this.onPointerDown,
  this.onPointerMove,
  this.onPointerUp,
  this.onPointerCancel,
  this.behavior: HitTestBehavior.deferToChild,
  Widget child
}) : super(key: key, child: child) {
  assert(behavior != null);
}