ReorderItemProxyDecorator typedef Null safety
Signature for the builder callback used to decorate the dragging item in ReorderableList and SliverReorderableList.
The child will be the item that is being dragged, and index is the
position of the item in the list.
The animation will be driven forward from 0.0 to 1.0 while the item is
being picked up during a drag operation, and reversed from 1.0 to 0.0 when
the item is dropped. This can be used to animate properties of the proxy
like an elevation or border.
The returned value will typically be the child wrapped in other widgets.
Implementation
typedef ReorderItemProxyDecorator = Widget Function(Widget child, int index, Animation<double> animation);