onWillAccept property Null safety
final
Called to determine whether this widget is interested in receiving a given piece of data being dragged over this drag target.
Called when a piece of data enters the target. This will be followed by either onAccept and onAcceptWithDetails, if the data is dropped, or onLeave, if the drag leaves the target.
Implementation
final DragTargetWillAccept<T>? onWillAccept;