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

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:tsacdop/class/episodebrief.dart';
import 'package:tsacdop/episodes/episodedetail.dart';
import 'package:tsacdop/util/pageroute.dart';
import 'package:tsacdop/util/colorize.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);

  @override
  Widget build(BuildContext context) {
    double _width = MediaQuery.of(context).size.width;
    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 = 
                (Theme.of(context).brightness == Brightness.light)
                    ?  podcast[index].primaryColor.colorizedark()
                    :  podcast[index].primaryColor.colorizeLight();
                return Material(
                  color: Colors.transparent,
                  child: 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:
                                Theme.of(context).brightness == Brightness.light
                                    ? Theme.of(context).primaryColor
                                    : Theme.of(context).scaffoldBackgroundColor,
                            width: 3.0,
                          ),
                          boxShadow: [
                            BoxShadow(
                              color: Theme.of(context).primaryColor,
                              blurRadius: 0.5,
                              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(
                                    height: _width / 16,
                                    width: _width / 16,
                                    child: CircleAvatar(
                                      backgroundImage: FileImage(
                                          File("${podcast[index].imagePath}")),
                                    ),
                                  ),
                                ),
                                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].dateToString(),
                                    //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,
            ),
          ),
        ),
      ],
    );
  }
}

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});
}