Mobile app initial implementation.

Closes #3 (closed)

lib/screens/home.dart

 import 'package:flutter/material.dart';
 import 'package:flutter_web_browser/flutter_web_browser.dart';
 import 'package:flutter_app_auth_wrapper/flutter_app_auth_wrapper.dart';
+import 'package:url_launcher/url_launcher.dart';
 import 'dart:developer';
+import 'dart:convert';
 
 class Home extends StatefulWidget {
-  Home({@required this.mode});
+  Home({@required this.mode, @required this.invokerURL});
   final String mode;
+  final String invokerURL;
 
   @override
   _HomeState createState() => _HomeState();
@@ -25,6 +28,38 @@ class _HomeState extends State<Home> {
   initState() {
     super.initState();
     showMode(widget.mode);
+
+    FlutterAppAuthWrapper.eventStream().listen((data) {
+      var token = json.decode(data.toString())["access_token"];
+      _showAlert(token);
+    });
+  }
+
+  Future<void> _showAlert(token) {
+    return showDialog<void>(
+      context: context,
+      builder: (BuildContext context) {
+        return AlertDialog(
+          title: Text('Authorization success'),
+          actions: <Widget>[
+            FlatButton(
+              child: Text('Go back'),
+              onPressed: () async {
+                Navigator.of(context).pop();
+
+                log('Try run ${widget.invokerURL}');
+                if (await canLaunch(widget.invokerURL)) {
+                  log('Run ${widget.invokerURL}');
+                  await launch(widget.invokerURL);
+                } else {
+                  log('Could not launch ${widget.invokerURL}');
+                }
+              },
+            ),
+          ],
+        );
+      },
+    );
   }
 
   @override
@@ -41,27 +76,36 @@ class _HomeState extends State<Home> {
   showMode(mode) {
     log(mode);
     if (mode == "app") {
-      FlutterWebBrowser.openWebPage(url: 'https://app.vereign.com', androidToolbarColor: Colors.deepPurple);
+      openVereign();
     } else if (mode == "oauth") {
-      FlutterAppAuthWrapper.startAuth(
-        AuthConfig(
-          clientId: clientId,
-          clientSecret: clientSecret,
-          redirectUrl: redirectURL,
-          state: "login",
-          prompt: "consent",
-          endpoint: AuthEndpoint(
-              auth: authEndpoint, token: tokenEndpoint),
-          scopes: [
-            "user_account_status",
-            "user_territory",
-            "user_profile"
-          ],
-        ),
-      );
+      startOAuth();
     }
   }
 
+  openVereign() {
+    FlutterWebBrowser.openWebPage(url: 'https://app.vereign.com', androidToolbarColor: Colors.deepPurple);
+  }
+
+  startOAuth() {
+    FlutterAppAuthWrapper.startAuth(
+      AuthConfig(
+        clientId: clientId,
+        clientSecret: clientSecret,
+        redirectUrl: redirectURL,
+        state: "login",
+        prompt: "consent",
+        endpoint: AuthEndpoint(
+            auth: authEndpoint, token: tokenEndpoint),
+        scopes: [
+          "user_account_status",
+          "user_territory",
+          "user_profile"
+        ],
+      ),
+    );
+  }
+
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -70,20 +114,21 @@ class _HomeState extends State<Home> {
                 child: Column(
                   mainAxisAlignment: MainAxisAlignment.center,
                   crossAxisAlignment: CrossAxisAlignment.stretch,
-                  children: _links.map((link) => _urlButton(context, link)).toList(),
+//                  children: _links.map((link) => _urlButton(context, link)).toList(),
+                  children: <Widget>[
+                    _urlButton(context, _links[0], "Open Vereign", openVereign),
+                    _urlButton(context, _links[1], "Authorize with Vereign", startOAuth),
+                  ]
                 ))));
   }
-  Widget _urlButton(BuildContext context, String url) {
+  Widget _urlButton(BuildContext context, String url, String title, listener) {
     return Container(
         padding: EdgeInsets.all(20.0),
         child: FlatButton(
           color: Theme.of(context).primaryColor,
           padding: const EdgeInsets.symmetric(horizontal: 50.0, vertical: 15.0),
-          child: Text(url),
-          onPressed: () => _handleURLButtonPress(context, url),
+          child: Text(title),
+          onPressed: listener
         ));
   }
-  void _handleURLButtonPress(BuildContext context, String url) async {
-    FlutterWebBrowser.openWebPage(url: url, androidToolbarColor: Colors.deepPurple);
-  }
 }
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