gopher/lib/page/gopher.dart

import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:share/share.dart';
import 'dart:io';
import 'dart:convert';
import '../constants.dart';
import '../gopher.dart';
import './text.dart';
import './image.dart';

class GopherPage extends StatefulWidget {
  final Uri uri;

  const GopherPage({Key key, this.uri}) : super(key: key);

  createState() => new GopherPageState();

  static void openURI(BuildContext context, Uri uri) {
    if (!uri.hasScheme || uri.scheme == "gopher") {
      Navigator.push(context, MaterialPageRoute<void>(
        builder: (BuildContext context) {
          return GopherPage(uri: uri);
        },
      ));
    } else {
      Scaffold.of(context).showSnackBar(
          const SnackBar(content: Text("URL does not have the gopher scheme")));
    }
  }
}
class GopherPageState extends State<GopherPage> {
  var content = <Widget>[];
  var done = false;
  TextStyle tstyle = const TextStyle(fontFamily: 'monospace', fontSize: DEFAULT_FONT_SIZE);

  GopherPageState() {
    SharedPreferences.getInstance().then((prefs) {
      setState(() { this.tstyle = TextStyle(fontFamily: 'monospace', fontSize: prefs.getDouble('font_size')); });
    });
  }

  void initState() {
    super.initState();
    _fetchContent(widget.uri);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(generateGopherTitle(widget.uri)),
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.home),
            tooltip: "go back",
            onPressed: () => Navigator.popUntil(context, ModalRoute.withName('/'))
          ),
          IconButton(
            icon: Icon(Icons.share),
            tooltip: "Share URL",
            onPressed: () => Share.share(widget.uri.toString()),
          ),
        ],
      ),
      body: ListView.builder(
          padding: EdgeInsets.all(4.0),
          itemBuilder: (BuildContext context, int index) {
            if (index < content.length) {
              return content[index];
            } else if (!done && content.length == index) {
              return Divider(color: Colors.red);
            } else {
              return null;
            }
          }),
    );
  }

  void _launchURL(BuildContext context, String url) async {
    if (await canLaunch(url)) {
      await launch(url);
    } else {
      Scaffold.of(context)
          .showSnackBar(const SnackBar(content: Text("Unable to open URL")));
    }
  }

  void _fetchContent(Uri uri) {
    var path = GopherPath(uri.path);
    if (path.type != GopherType.Directory && path.type != GopherType.Search)
      throw "Invalid gopher type, expected 1 or 7";
    Socket.connect(uri.host, uri.port != 0 ? uri.port : 70).then((socket) {
      socket.write(Uri.decodeComponent(path.selector) + "\r\n");
      socket
          .cast<List<int>>()
          .transform(utf8.decoder)
          .transform(const LineSplitter())
          .forEach((line) {
        if (mounted) {
          setState(() {
            if (line.isNotEmpty) {
              var type = line.substring(0, 1);
              var fields = line.substring(1).split("\t");

              Uri buildUri(String type) {
                return Uri(
                    scheme: "gopher",
                    host: fields[2],
                    path: "/" + type + fields[1],
                    port: int.parse(fields[3]));
              }

              switch (type) {
                case "0":
                  content.add(ListTile(
                      title: Text(fields[0], style: tstyle),
                      trailing: Icon(Icons.short_text),
                      onTap: () {
                        TextPage.openURI(context, buildUri("0"));
                      }));
                  break;
                case "1":
                  content.add(ListTile(
                      title: Text(fields[0], style: tstyle),
                      trailing: Icon(Icons.arrow_forward),
                      onTap: () {
                        GopherPage.openURI(context, buildUri("1"));
                      }));
                  break;
                case "3":
                  content.add(Padding(
                    child: ListTile(
                        title: Text(fields[0], style: tstyle),
                        trailing: Icon(Icons.error, color: Colors.red)),
                    padding: EdgeInsets.fromLTRB(16.0, 0.0, 16.0, 2.0),
                  ));
                  break;
                case "7":
                  content.add(ListTile(
                      title: Text(fields[0], style: tstyle),
                      trailing: Icon(Icons.search),
                      onTap: () {
                        showDialog<void>(
                          context: context,
                          builder: (BuildContext context) {
                            return SimpleDialog(
                              title: const Text("Search"),
                              contentPadding: const EdgeInsets.fromLTRB(
                                  12.0, 12.0, 12.0, 16.0),
                              children: <Widget>[
                                TextField(
                                  autofocus: true,
                                  enabled: true,
                                  enableInteractiveSelection: true,
                                  onSubmitted: (s) {
                                    Navigator.of(context).pop(true);
                                    GopherPage.openURI(
                                        context,
                                        Uri(
                                          host: fields[2],
                                          path: "/7" + fields[1] + "\t" + s,
                                          port: int.parse(fields[3]),
                                        ));
                                  },
                                ),
                              ],
                            );
                          },
                        );
                      }));
                  break;
                case "i":
                  content.add(Padding(
                    child: Text(
                      fields[0],
                      style: tstyle,
                      softWrap: true,
                    ),
                    padding: EdgeInsets.fromLTRB(16.0, 0.0, 16.0, 2.0),
                  ));
                  break;
                case "h":
                  const PREFIX = "URL:";
                  content.add(ListTile(
                      title: Text(fields[0], style: tstyle),
                      trailing: Icon(fields[1].startsWith(PREFIX)
                          ? Icons.launch
                          : Icons.block),
                      onTap: () {
                        if (fields[1].startsWith(PREFIX)) {
                          _launchURL(context, fields[1].substring(4));
                        } else {
                          Scaffold.of(context).showSnackBar(const SnackBar(
                              content: Text("Malformed gopher entry")));
                        }
                      }));
                  break;
                case "g":
		case "G":
		case "i":
                case "I":
		case "p":
		case "P":
                  content.add(ListTile(
                    title: Text(fields[0], style: tstyle),
                      trailing: Icon(Icons.arrow_forward),
                      onTap: () {
                        ImagePage.openURI(context, buildUri(type));
                      }));
		  break;
                case ".":
                  content.add(Divider(color: Colors.green));
                  done = true;
                  break;
                default:
                  content.add(ListTile(
                    title: Text(fields[0], style: tstyle),
                    trailing: Stack(
                      alignment: AlignmentDirectional.center,
                      children: <Widget>[
                        Text(type),
                        Icon(Icons.block, color: Colors.pink.withAlpha(150)),
                      ],
                    ),
                  ));
                  break;
              }
            }
          });
        }
      });
    }).catchError((e) { Navigator.pop(context); });
  }
}