dragUpdate method
Implementation
void dragUpdate(DragUpdateDetails details) {
final HitTestResult result = HitTestResult();
WidgetsBinding.instance.hitTest(result, details.globalPosition);
final List<MultiLevelDraggableState> targets =
getTargets(result.path).toList();
var parent = MultiLevelDraggableParentState.maybeOf(context);
assert(parent != null);
if (targets.isNotEmpty) {
parent?.setState(() {
parent.currentDragOn = targets.first;
});
}
setState(() {
dragData?.dragPosition += details.delta;
overlayEntry?.markNeedsBuild();
});
}