gecko/lib/home.dart

import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:typed_data';
import 'dart:ui';
import 'package:permission_handler/permission_handler.dart';
import 'package:qrscan/qrscan.dart' as scanner;
import 'package:graphql_flutter/graphql_flutter.dart';
import 'api.dart';
import 'query.dart';

//ignore: must_be_immutable
class HistoryListScreen extends StatelessWidget with ChangeNotifier {
  Uint8List bytes = Uint8List(0);
  final TextEditingController _outputPubkey = new TextEditingController();
  final nRepositories = 3;
  String pubkey = 'D2meevcAHFTS2gQMvmRW5Hzi25jDdikk4nC4u1FkwRaU'; // For debug
  bool isBuilding = true; // Just for debug
  ScrollController _scrollController = new ScrollController();

  @override
  Widget build(BuildContext context) {
    print('Build pubkey : ' + pubkey);
    print('Build this.pubkey : ' + this.pubkey);
    print('isBuilding: ' + isBuilding.toString());
    return MaterialApp(
        home: Scaffold(
            backgroundColor: Colors.grey[300],
            body: SafeArea(
              child: Column(
                children: masterHome,
              ),
            ),
            floatingActionButton: Container(
              height: 80.0,
              width: 80.0,
              child: FittedBox(
                child: FloatingActionButton(
                  onPressed: () => _scan(),
                  child: Container(
                      height: 40.0,
                      width: 40.0,
                      child: Image.asset('images/scanner.png')),
                  backgroundColor: Color.fromARGB(500, 204, 255, 255),
                ),
              ),
            )));
  }

  List<Widget> get masterHome {
    return <Widget>[
      SizedBox(height: 20),
      TextField(
          onChanged: (text) {
            print("Clé tappxé: $text");
            this.pubkey = text;
            isPubkey(text);
          },
          controller: this._outputPubkey,
          maxLines: 1,
          textAlign: TextAlign.center,
          decoration: InputDecoration(
            hintText: 'Tappez/Collez une clé publique, ou scannez',
            hintStyle: TextStyle(fontSize: 15),
            contentPadding: EdgeInsets.symmetric(horizontal: 7, vertical: 15),
            border: InputBorder.none,
            focusedBorder: InputBorder.none,
            enabledBorder: InputBorder.none,
            errorBorder: InputBorder.none,
            disabledBorder: InputBorder.none,
          ),
          style: TextStyle(
              fontSize: 15.0,
              color: Colors.black,
              fontWeight: FontWeight.bold)),
      historyQuery(),
    ];
  }

  Expanded historyQuery() {
    return Expanded(
        child: Column(
      mainAxisAlignment: MainAxisAlignment.start,
      mainAxisSize: MainAxisSize.max,
      children: <Widget>[
        Query(
          options: QueryOptions(
            document: gql(getHistory),
            variables: <String, dynamic>{
              'pubkey': this.pubkey,
              'number': nRepositories,
              // set cursor to null so as to start at the beginning
              'cursor': null
            },
          ),
          builder: (QueryResult result, {refetch, FetchMore fetchMore}) {
            if (result.isLoading && result.data == null) {
              return const Center(
                child: CircularProgressIndicator(),
              );
            }

            if (result.hasException) {
              return Text('\nErrors: \n  ' + result.exception.toString());
            }

            if (result.data == null && result.exception.toString() == null) {
              return const Text('Both data and errors are null');
            }

            final List<dynamic> blockchainTX =
                (result.data['txsHistoryBc']['both']['edges'] as List<dynamic>);

            final Map pageInfo =
                result.data['txsHistoryBc']['both']['pageInfo'];

            final String fetchMoreCursor =
                pageInfo['endCursor'] ?? 'cest null...';

            FetchMoreOptions opts = FetchMoreOptions(
              variables: {'cursor': fetchMoreCursor},
              updateQuery: (previousResultData, fetchMoreResultData) {
                final List<dynamic> repos = [
                  ...previousResultData['txsHistoryBc']['both']['edges']
                      as List<dynamic>,
                  ...fetchMoreResultData['txsHistoryBc']['both']['edges']
                      as List<dynamic>
                ];

                fetchMoreResultData['txsHistoryBc']['both']['edges'] = repos;
                return fetchMoreResultData;
              },
            );

            _scrollController
              ..addListener(() {
                if (_scrollController.position.pixels ==
                    _scrollController.position.maxScrollExtent) {
                  if (!result.isLoading) {
                    print(
                        "DEBUG H fetchMoreCursor in scrollController: $fetchMoreCursor");
                    fetchMore(opts);
                  }
                }
              });

            print(
                "###### DEBUG H Parse blockchainTX list. Cursor: $fetchMoreCursor ######");
            List _transBC = parseHistory(blockchainTX);

            return Expanded(
              child: HistoryListView(
                  scrollController: _scrollController,
                  transBC: _transBC,
                  historyData: result),
            );
          },
        ),
      ],
    ));
  }

  Future _scan() async {
    await Permission.camera.request();
    String barcode = await scanner.scan();
    // this._outputPubkey.text = "";
    if (barcode != null) {
      this._outputPubkey.text = barcode;
      isPubkey(barcode);
    }
    return barcode;
  }

  String isPubkey(pubkey) {
    // final validCharacters = RegExp(r'^[a-zA-Z0-9]+$');
    RegExp regExp = new RegExp(
      r'^[a-zA-Z0-9]+$',
      caseSensitive: false,
      multiLine: false,
    );

    if (regExp.hasMatch(pubkey) == true &&
        pubkey.length > 42 &&
        pubkey.length < 45) {
      print("C'est une pubkey !!!");

      return pubkey;
    }

    return '';
  }
}

class HistoryListView extends StatelessWidget {
  const HistoryListView(
      {Key key,
      @required ScrollController scrollController,
      @required this.transBC,
      @required this.historyData})
      : _scrollController = scrollController,
        super(key: key);

  final ScrollController _scrollController;
  final List transBC;
  final historyData;

  @override
  Widget build(BuildContext context) {
    return ListView(
      controller: _scrollController,
      children: <Widget>[
        for (var repository in transBC)
          Card(
            // 1
            elevation: 2.0,
            // 2
            shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(3.0)),
            // 3
            child: Padding(
              padding: const EdgeInsets.all(100.0),
              // 4
              child: Column(
                children: <Widget>[
                  SizedBox(
                    height: 8.0,
                  ),
                  Text(
                    // Date
                    repository[1].toString(),
                    style: TextStyle(
                      fontSize: 12.0,
                      fontWeight: FontWeight.w300,
                    ),
                  ),
                  Text(
                    // Issuer
                    repository[2],
                    style: TextStyle(
                      fontSize: 13.0,
                      fontWeight: FontWeight.w500,
                    ),
                  ),
                  Text(
                    // Amount
                    repository[3].toString(),
                    style: TextStyle(
                      fontSize: 15.0,
                      fontWeight: FontWeight.w500,
                    ),
                  ),
                  Text(
                    // Comment
                    repository[5].toString(),
                    style: TextStyle(
                      fontSize: 12.0,
                      fontWeight: FontWeight.w400,
                    ),
                  ),
                ],
              ),
            ),
          ),
        if (historyData.isLoading)
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              CircularProgressIndicator(),
            ],
          ),
      ],
    );
  }
}