onUpdate property
getter/setter pair
A pointer that is in contact with the screen with a primary button and moving has moved again.
The distance traveled by the pointer since the last update is provided in
the callback's details argument, which is a DragUpdateDetails object.
If this gesture recognizer recognizes movement on a single axis (a
VerticalDragGestureRecognizer or HorizontalDragGestureRecognizer),
then details will reflect movement only on that axis and its
DragUpdateDetails.primaryDelta will be non-null.
If this gesture recognizer recognizes movement in all directions
(a PanGestureRecognizer), then details will reflect movement on
both axes and its DragUpdateDetails.primaryDelta will be null.
See also:
- allowedButtonsFilter, which decides which button will be allowed.
- DragUpdateDetails, which is passed as an argument to this callback.
Implementation
GestureDragUpdateCallback? onUpdate;