Mobile app initial implementation.

Closes #3 (closed)

lib/src/app.dart

+// app.dart
+import 'screens/splashscreen.dart';
+import 'package:flutter/material.dart';
+import 'screens/home.dart';
+import 'package:flutter/services.dart';
+import 'dart:async';
+import 'dart:developer';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'package:uni_links/uni_links.dart';
+
+class App extends StatelessWidget {
+  Future<Widget> initApplication() async {
+    Uri initialUri;
+
+    try {
+      initialUri = await getInitialUri();
+    } on PlatformException {
+      initialUri = null;
+    } on FormatException {
+      initialUri = null;
+    }
+
+    final prefs = await SharedPreferences.getInstance();
+    final host = prefs.getString('host');
+
+    return new MainApp(initialUri: initialUri, initialHost: host);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+        title: 'Vereign',
+        theme: ThemeData(
+            primaryColor: Color(0xFFd51d32),
+            fontFamily: "Arial",
+            textTheme: TextTheme(
+                button: TextStyle(color: Colors.white, fontSize: 18.0),
+                title: TextStyle(color: Colors.red))),
+        home: new SplashScreen(
+          navigateAfterFuture: initApplication,
+        )
+    );
+
+
+  }
+}
+
+class MainApp extends StatefulWidget {
+  MainApp({ @required this.initialUri, this.initialHost });
+  final Uri initialUri;
+  final String initialHost;
+
+  @override
+  _MainAppState createState() => _MainAppState();
+}
+
+class _MainAppState extends State<MainApp> {
+  StreamSubscription _sub;
+
+  String _appMode = "";
+
+  // Url of the app which invoked OAuth
+  String _invokerURL;
+  String _host;
+
+  @override
+  initState() {
+    super.initState();
+    initUniLinks();
+  }
+
+  @override
+  dispose() {
+    if (_sub != null) _sub.cancel();
+    super.dispose();
+  }
+
+  Future<Null> initUniLinks() async {
+    updateAppMode(widget.initialUri);
+
+    _sub = getUriLinksStream().listen((Uri uri) {
+      updateAppMode(uri);
+    }, onError: (err) {
+      log('got err: $err');
+    });
+  }
+
+  updateAppMode(Uri uri) {
+    if (uri?.path == "/authorize") {
+      setState(() {
+        _appMode = "oauth";
+        _invokerURL = uri.queryParameters["invokerUrl"];
+      });
+    } else {
+      setState(() {
+        _appMode = "app";
+      });
+    }
+  }
+
+  setMode(String mode) {
+    setState(() {
+      _appMode = mode;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return new Scaffold(
+      appBar: new AppBar(title: Text("Vereign")),
+      body: Home(
+        mode: _appMode,
+        invokerURL: _invokerURL,
+        setMode: setMode,
+        host: widget.initialHost
+      )
+    );
+  }
+}
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