GestureDragEndCallback typedef

void GestureDragEndCallback (DragEndDetails details)

Signature for when a pointer that was previously in contact with the screen and moving is no longer in contact with the screen.

The velocity at which the pointer was moving when it stopped contacting the screen is available in the details.

See DragGestureRecognizer.onEnd.

Implementation 

typedef GestureDragEndCallback = void Function(DragEndDetails details);