Adding top and bottom separators with ListView.separated

Jan 12, 2020

ListView.separated is a handy API that we can use to add separators between items inside a Flutter ListView.

Separators only appear between list items: separator 0 appears after item 0 and the last separator appears before the last item.

This means that there are no separators above the first item, and below the last item.

This is visually noticeable on iOS, where lists can over-scroll by default.

Here's some code to set things straight, and add top and bottom separators to your ListViews:

class ListViewWithAllSeparators<T> extends StatelessWidget {
  const ListViewWithAllSeparators({Key key, this.items, this.itemBuilder}) : super(key: key);
  final List<T> items;
  final Widget Function(BuildContext context, T item) itemBuilder;

  @override
  Widget build(BuildContext context) {
    return ListView.separated(
      itemCount: items.length + 2,
      separatorBuilder: (_, __) => Divider(height: 0.5),
      itemBuilder: (context, index) {
        if (index == 0 || index == items.length + 1) {
          return Container(); // zero height: not visible
        }
        return itemBuilder(context, items[index - 1]);
      },
    );
  }
}