infinite_listview library Null safety


Indexed List View [...]
Provides scroll with infinite bounds, and keeps a scroll-position and a origin-index. The scroll-position is the number of pixels of scroll, considering the item at origin-index as the origin (0.0). So, for example, if you have scroll-position 10.0 and origin-index 15, then you are 10 pixels after the 15th item. [...]


IndexedWidgetBuilderOrNull = Widget? Function(BuildContext context, int index)
The builder should create a widget for the given index. When the builder returns null, the list will ask the emptyItemBuilder to create an "empty" item to be displayed instead.