Callback signature for LongPressGestureRecognizer.onLongPressDown.
Called when a pointer that might cause a long-press has contacted the
screen. The position at which the pointer contacted the screen is available
- GestureDetector.onLongPressDown, which matches this signature.
- GestureLongPressStartCallback, the signature that gets called when the pointer has been in contact with the screen long enough to be considered a long-press.
typedef GestureLongPressDownCallback = void Function(LongPressDownDetails details);