onDragUpdate method

@override bool onDragUpdate(DragUpdateEvent event)

The user has moved the pointer that initiated the drag gesture.

This event will be delivered to the component(s) that captured the initial onDragStart, even if the point of touch moves outside of the boundaries of the component. In the latter case event.localPosition will contain a NaN point.

Implementation

@override
bool onDragUpdate(DragUpdateEvent event) {
  _unscaledDelta.add(event.localDelta);
  return false;
}