tsacdop-podcast-app-android/lib/util/episodegrid.dart

import 'dart:convert';
import 'dart:io';
import 'dart:isolate';
import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:flutter_downloader/flutter_downloader.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:path_provider/path_provider.dart';
import 'package:tsacdop/class/episodebrief.dart';
import 'package:tsacdop/episodes/episodedetail.dart';
import 'package:tsacdop/util/pageroute.dart';

class EpisodeGrid extends StatelessWidget {
  final List<EpisodeBrief> podcast;
  final bool showFavorite;
  final bool showDownload;
  final bool showNumber;
  final String heroTag;
  EpisodeGrid(
      {Key key,
      this.podcast,
      this.showDownload,
      this.showFavorite,
      this.showNumber,
      this.heroTag})
      : super(key: key);
  double _width;
  Future<String> _getPath() async {
    print(_width);
    var dir = await getApplicationDocumentsDirectory();
    return dir.path;
  }

  @override
  Widget build(BuildContext context) {
    _width = MediaQuery.of(context).size.width;
    return FutureBuilder(
        future: _getPath(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            return CustomScrollView(
              physics: const AlwaysScrollableScrollPhysics(),
              primary: false,
              slivers: <Widget>[
                SliverPadding(
                  padding: const EdgeInsets.all(5.0),
                  sliver: SliverGrid(
                    gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                      childAspectRatio: 1.0,
                      crossAxisCount: 3,
                      mainAxisSpacing: 6.0,
                      crossAxisSpacing: 6.0,
                    ),
                    delegate: SliverChildBuilderDelegate(
                      (BuildContext context, int index) {
                        Color _c;
                        var color = json.decode(podcast[index].primaryColor);
                        (color[0] > 200 && color[1] > 200 && color[2] > 200)
                            ? _c = Color.fromRGBO((255 - color[0]),
                                255 - color[1], 255 - color[2], 1.0)
                            : _c = Color.fromRGBO(
                                color[0], color[1], color[2], 1.0);
                        return InkWell(
                          onTap: () {
                            Navigator.push(
                              context,
                              ScaleRoute(
                                  page: EpisodeDetail(
                                      episodeItem: podcast[index],
                                      heroTag: heroTag)),
                            );
                          },
                          child: Container(
                            decoration: BoxDecoration(
                                borderRadius:
                                    BorderRadius.all(Radius.circular(5.0)),
                                color:
                                    Theme.of(context).scaffoldBackgroundColor,
                                border: Border.all(
                                  color: Colors.grey[100],
                                  width: 3.0,
                                ),
                                boxShadow: [
                                  BoxShadow(
                                    color: Colors.grey[100],
                                    blurRadius: 1.0,
                                    spreadRadius: 0.5,
                                  ),
                                ]),
                            alignment: Alignment.center,
                            padding: EdgeInsets.all(8.0),
                            child: Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: <Widget>[
                                Expanded(
                                  flex: 2,
                                  child: Row(
                                    mainAxisAlignment: MainAxisAlignment.start,
                                    children: <Widget>[
                                      Hero(
                                        tag: podcast[index].enclosureUrl +
                                            heroTag,
                                        child: Container(
                                          child: ClipRRect(
                                            borderRadius: BorderRadius.all(
                                                Radius.circular(_width/32)),
                                            child: Container(
                                              height: _width/16,
                                              width: _width/16,
                                              child: Image.file(File(
                                                  "${snapshot.data}/${podcast[index].feedTitle}.png")),
                                            ),
                                          ),
                                        ),
                                      ),
                                      Spacer(),
                                      showNumber
                                          ? Container(
                                              alignment: Alignment.topRight,
                                              child: Text(
                                                (podcast.length - index)
                                                    .toString(),
                                                style: GoogleFonts.teko(
                                                  textStyle: TextStyle(
                                                    fontSize: _width/24,
                                                    color: _c,
                                                  ),
                                                ),
                                              ),
                                            )
                                          : Center(),
                                    ],
                                  ),
                                ),
                                Expanded(
                                  flex: 5,
                                  child: Container(
                                    alignment: Alignment.topLeft,
                                    padding: EdgeInsets.only(top: 2.0),
                                    child: Text(
                                      podcast[index].title,
                                      style: TextStyle(
                                        fontSize: _width/32,
                                      ),
                                      maxLines: 4,
                                      overflow: TextOverflow.fade,
                                    ),
                                  ),
                                ),
                                Expanded(
                                  flex: 1,
                                  child: Row(
                                    children: <Widget>[
                                      Align(
                                        alignment: Alignment.bottomLeft,
                                        child: Text(
                                          podcast[index]
                                              .pubDate
                                              .substring(4, 16),
                                          style: TextStyle(
                                            fontSize: _width/35,
                                              color: _c,
                                              fontStyle: FontStyle.italic),
                                        ),
                                      ),
                                      Spacer(),
                                      showDownload
                                          ? DownloadIcon(
                                              episodeBrief: podcast[index])
                                          : Center(),
                                      Padding(
                                        padding: EdgeInsets.all(1),
                                      ),
                                      showFavorite
                                          ? Container(
                                              alignment: Alignment.bottomRight,
                                              child: (podcast[index].liked == 0)
                                                  ? Center()
                                                  : IconTheme(
                                                      data: IconThemeData(
                                                          size: 15),
                                                      child: Icon(
                                                        Icons.favorite,
                                                        color: Colors.red,
                                                      ),
                                                    ),
                                            )
                                          : Center(),
                                    ],
                                  ),
                                ),
                              ],
                            ),
                          ),
                        );
                      },
                      childCount: podcast.length,
                    ),
                  ),
                ),
              ],
            );
          }
          return Center();
        });
  }
}

class DownloadIcon extends StatefulWidget {
  final EpisodeBrief episodeBrief;
  DownloadIcon({this.episodeBrief, Key key}) : super(key: key);
  @override
  _DownloadIconState createState() => _DownloadIconState();
}

class _DownloadIconState extends State<DownloadIcon> {
  _TaskInfo _task;
  bool _isLoading;
  ReceivePort _port = ReceivePort();

  @override
  void initState() {
    super.initState();
    _bindBackgroundIsolate();

    FlutterDownloader.registerCallback(downloadCallback);

    _isLoading = true;
    _prepare();
  }

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

  void _bindBackgroundIsolate() {
    bool isSuccess = IsolateNameServer.registerPortWithName(
        _port.sendPort, 'downloader_send_port');
    if (!isSuccess) {
      _unbindBackgroundIsolate();
      _bindBackgroundIsolate();
      return;
    }

    _port.listen((dynamic data) {
      print('UI isolate callback: $data');
      String id = data[0];
      DownloadTaskStatus status = data[1];
      int progress = data[2];
      if (_task.taskId == id) {
        setState(() {
          _task.status = status;
          _task.progress = progress;
        });
      }
    });
  }

  void _unbindBackgroundIsolate() {
    IsolateNameServer.removePortNameMapping('downloader_send_port');
  }

  static void downloadCallback(
      String id, DownloadTaskStatus status, int progress) {
    print('Background callback task in $id  status ($status) $progress');
    final SendPort send =
        IsolateNameServer.lookupPortByName('downloader_send_port');
    send.send([id, status, progress]);
  }

  Future<Null> _prepare() async {
    final tasks = await FlutterDownloader.loadTasks();

    _task = _TaskInfo(
        name: widget.episodeBrief.title,
        link: widget.episodeBrief.enclosureUrl);

    tasks?.forEach((task) {
      if (_task.link == task.url) {
        _task.taskId = task.taskId;
        _task.status = task.status;
        _task.progress = task.progress;
      }
    });
    setState(() {
      _isLoading = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return _downloadButton(_task);
  }

  Widget _downloadButton(_TaskInfo task) {
    if (_isLoading)
      return Center();
    else if (task.status == DownloadTaskStatus.running) {
      return SizedBox(
        height: 12,
        width: 12,
        child: CircularProgressIndicator(
          backgroundColor: Colors.grey[200],
          strokeWidth: 1,
          valueColor: AlwaysStoppedAnimation<Color>(Colors.blue),
          value: task.progress / 100,
        ),
      );
    } else if (task.status == DownloadTaskStatus.paused) {
      return SizedBox(
        height: 12,
        width: 12,
        child: CircularProgressIndicator(
          backgroundColor: Colors.grey[200],
          strokeWidth: 1,
          valueColor: AlwaysStoppedAnimation<Color>(Colors.red),
          value: task.progress / 100,
        ),
      );
    } else if (task.status == DownloadTaskStatus.complete) {
      return IconTheme(
        data: IconThemeData(size: 15),
        child: Icon(
          Icons.done_all,
          color: Colors.blue,
        ),
      );
    } else if (task.status == DownloadTaskStatus.failed) {
      return IconTheme(
        data: IconThemeData(size: 15),
        child: Icon(Icons.refresh, color: Colors.red),
      );
    }
    return Center();
  }
}

class _TaskInfo {
  final String name;
  final String link;

  String taskId;
  int progress = 0;
  DownloadTaskStatus status = DownloadTaskStatus.undefined;

  _TaskInfo({this.name, this.link});
}