Determines the way that drag start behavior is handled.
If set to DragStartBehavior.start, the drag behavior used to move the switch from on to off will begin at the position where the drag gesture won the arena. If set to DragStartBehavior.down it will begin at the position where a down event was first detected.
By default, the drag start behavior is DragStartBehavior.start.
- DragGestureRecognizer.dragStartBehavior, which gives an example for the different behaviors.
final DragStartBehavior dragStartBehavior;