neonime-app/lib/pages/batch.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:async_loader/async_loader.dart';
import 'package:neonime_app/scrapper/batch.dart';
import 'batch-detail.dart';

class Batch extends StatefulWidget {
  @override
  _BatchState createState() => _BatchState();
}

class _BatchState extends State<Batch>
    with AutomaticKeepAliveClientMixin<Batch> {
  final GlobalKey<AsyncLoaderState> asyncLoaderState =
      new GlobalKey<AsyncLoaderState>();
  ScrollController _scrollController = new ScrollController();
  List listData;

  Future<Null> _handleRefresh() async {
    asyncLoaderState.currentState.reloadState();
    return null;
  }

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(() {
      if (_scrollController.position.pixels ==
          _scrollController.position.maxScrollExtent) {
        _getMoreData();
      }
    });
  }

  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  }

  void _getMoreData() async {
    final nextPage = (listData.length / 15) + 1;
    List newData = await getBatch(nextPage.round().toString()).then((x) {
      return x;
    });
    setState(() {
      listData.addAll(newData);
    });
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      appBar: AppBar(title: Text('Batch'),),
      body: Center(
        child: RefreshIndicator(
          onRefresh: () => _handleRefresh(),
          child: AsyncLoader(
              key: asyncLoaderState,
              initState: () async => await getBatch('1'),
              renderLoad: () => new CircularProgressIndicator(),
              renderError: ([error]) {
                print(error);
                return Text(error.toString());
              },
              renderSuccess: ({data}) {
                listData = data;
                return ListView.builder(
                  controller: _scrollController,
                  itemCount: data.length,
                  itemBuilder: (context, index) {
                    return Card(
                      margin: EdgeInsets.all(10),
                      child: InkWell(
                        onTap: () {
                          Navigator.push(
                              context,
                              MaterialPageRoute(
                                  builder: (context) => BatchDetail(),
                                  settings: RouteSettings(arguments: {
                                    'title': listData[index]['title'],
                                    'url': listData[index]['link']
                                  })));
                        },
                        child: Column(
                          children: [
                            Container(
                              child: CachedNetworkImage(
                                imageUrl: listData[index]['image'],
                                placeholder: (context, url) => CupertinoActivityIndicator(),
                                errorWidget: (context, url, error) => Image.asset('lib/assets/image-error.jpg'),
                                fadeOutDuration: Duration(milliseconds: 5),
                                imageBuilder: (context, imageProvider) => Container(
                                  width: 400,
                                  height: 210,
                                  decoration: BoxDecoration(
                                    image: DecorationImage(
                                      image: imageProvider,
                                      fit: BoxFit.cover
                                    ),
                                  ),
                                ),
                              )
                            ),
                            Container(
                              margin: EdgeInsets.all(10),
                              child: Text(
                                listData[index]['title'],
                                style: TextStyle(fontSize: 20),
                                textAlign: TextAlign.center,
                              ),
                            )
                          ],
                        ),
                      ),
                    );
                  },
                );
              }),
        ),
      ),
    );
  }

  @override
  bool get wantKeepAlive => true;
}