circle_indicator.dart

import 'package:flutter/material.dart';

class CircleIndicator {
  static Widget show() {
    return Center(
      child: new SizedBox(
        height: 50.0,
        width: 50.0,
        child: new CircularProgressIndicator(
          value: null,
          strokeWidth: 7.0,
        ),
      ),
    );
  }
}

sample.dart

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(widget.keyword),
        ),
        body: FutureBuilder(
            future: _fetchSearchKeyword(widget.keyword),
            builder:
                (BuildContext context, AsyncSnapshot<Autogenerated> snapshot) {
              if (snapshot.hasError) {
                print("snapshot.error: ${snapshot.error.toString()}");
                return Container();
              }

              if (snapshot.hasData == false) {
                return CircleIndicator.show();
              }

              final items = snapshot.data.response.body.items.item;

              return ListView.builder(
                physics: ClampingScrollPhysics(),
                scrollDirection: Axis.vertical,
                itemCount: items.length,
                itemBuilder: (context, index) {
                  final item = items[index];

                  final contentValue = new ContentValue(
                      areaCode: item.areacode,
                      contentId: item.contentid,
                      contentTypeId: item.contenttypeid,
                      title: item.title,
                      imageUrl: item.firstimage);

                  final image = Utils.isNullOrEmpty(item.firstimage)
                      ? ImageUtil.noImageWidget()
                      : Image.network(item.firstimage, fit: BoxFit.cover);

                  return _buildFeaturedItem(context, contentValue, () {
                    print("keyword: ${widget.keyword}, title: ${item.title}");

                    Navigator.push(
                        context,
                        MaterialPageRoute(
                            builder: (context) => ContentTypeDetail(
                                  contentValue: contentValue,
                                  imageWidget: image,
                                )));
                  }, title: item.title, image: image, subTitle: "");
                },
              );
            }));
  }