// view.dart
List<Widget> _buildTabBarView() {
    List<Widget> widgets = [];
    for (var i = 0; i < adapter.itemCount; i++) {
      widgets.add(adapter.itemBuilder(viewService.context, i));
    }
    return widgets;
 }

// state.dart
  @override
  Object getItemData(int index) {
    return lotteryStates[index];
  }

  @override
  String getItemType(int index) {
    if (lotteryStates[index] is GroupLotteryNewState) {
      return 'new';
    }
    return 'dtl';
  }

  @override
  int get itemCount => lotteryStates.length;

  @override
  void setItemData(int index, Object data) {
    lotteryStates[index] = data;
  }

// adapter.dart
class GroupLotteryAdapter extends SourceFlowAdapter<GroupLotteryState> {
  GroupLotteryAdapter()
      : super(
          pool: <String, Component<Object>>{
            'new': GroupLotteryNewComponent(),
            'dtl': GroupLotteryDtlComponent()
          },
        );
}