GestureTapDragUpdateCallback typedef
Signature for when a pointer that is in contact with the screen and moving has moved again.
The details
object provides the position of the touch and the distance it
has traveled since the last update.
The consecutive tap count at the time the pointer contacted the screen is given by TapDragUpdateDetails.consecutiveTapCount.
Implementation
typedef GestureTapDragUpdateCallback = void Function(TapDragUpdateDetails details);