LongPressDraggable({Key key, @required Widget child, @required Widget feedback, T data, Widget childWhenDragging, Offset feedbackOffset: Offset.zero, DragAnchor dragAnchor: DragAnchor.child, int maxSimultaneousDrags, VoidCallback onDragStarted, DraggableCanceledCallback onDraggableCanceled })

Creates a widget that can be dragged starting from long press.

The child and feedback arguments must not be null. If maxSimultaneousDrags is non-null, it must be non-negative.

Source 

LongPressDraggable({
  Key key,
  @required Widget child,
  @required Widget feedback,
  T data,
  Widget childWhenDragging,
  Offset feedbackOffset: Offset.zero,
  DragAnchor dragAnchor: DragAnchor.child,
  int maxSimultaneousDrags,
  VoidCallback onDragStarted,
  DraggableCanceledCallback onDraggableCanceled
}) : super(
  key: key,
  child: child,
  feedback: feedback,
  data: data,
  childWhenDragging: childWhenDragging,
  feedbackOffset: feedbackOffset,
  dragAnchor: dragAnchor,
  maxSimultaneousDrags: maxSimultaneousDrags,
  onDragStarted: onDragStarted,
  onDraggableCanceled: onDraggableCanceled
);