addded version check to prompt user to update

lib/api/version_check.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:package_info_plus/package_info_plus.dart';
+import 'dart:convert';
+import 'package:http/http.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+
+class VersionChecker {
+  GlobalKey<ScaffoldMessengerState> snackbarKey;
+  VersionChecker(this.snackbarKey);
+
+  String repo = "https://github.com/go-vikunja/app/releases/latest";
+
+  Future<String> getLatestVersionTag() async {
+    String api = "https://api.github.com/repos/go-vikunja/app";
+    String endpoint = "/releases";
+
+    return get(Uri.parse(api + endpoint)).then((response) {
+      dynamic jsonResponse = json.decode(response.body);
+      String latestVersion = jsonResponse[0]['tag_name'];
+      if (latestVersion.startsWith("v")) {
+        latestVersion = latestVersion.replaceFirst("v", "");
+      }
+      return latestVersion;
+    });
+  }
+
+  Future<String> getCurrentVersionTag() async {
+    PackageInfo packageInfo = await PackageInfo.fromPlatform();
+    print("current: " + packageInfo.version);
+    return packageInfo.version;
+  }
+
+  Future<bool> isUpToDate() async {
+    String latest = await getLatestVersionTag();
+    String current = await getCurrentVersionTag();
+    return latest == current;
+  }
+
+  postVersionCheckSnackbar() async {
+    String latest = await getLatestVersionTag();
+    isUpToDate().then((value) {
+      if (!value) {
+        // not up to date
+        SnackBar snackBar = SnackBar(
+          content: Text("New version available: $latest"),
+          action: SnackBarAction(
+              label: "View on Github",
+              onPressed: () => launchUrl(Uri.parse(repo), mode: LaunchMode.externalApplication)),
+        );
+        snackbarKey.currentState?.showSnackBar(snackBar);
+      }
+    });
+  }
+}

lib/global.dart

@@ -1,4 +1,3 @@
-import 'dart:math';
 import 'dart:developer' as dev;
 
 import 'package:flutter/material.dart';
@@ -14,12 +13,12 @@ import 'package:vikunja_app/api/namespace_implementation.dart';
 import 'package:vikunja_app/api/server_implementation.dart';
 import 'package:vikunja_app/api/task_implementation.dart';
 import 'package:vikunja_app/api/user_implementation.dart';
+import 'package:vikunja_app/api/version_check.dart';
 import 'package:vikunja_app/managers/notifications.dart';
 import 'package:vikunja_app/managers/user.dart';
 import 'package:vikunja_app/models/user.dart';
 import 'package:vikunja_app/service/services.dart';
 import 'package:timezone/data/latest_all.dart' as tz;
-import 'package:timezone/timezone.dart' as tz;
 import 'package:flutter_local_notifications/flutter_local_notifications.dart'as notifs;
 
 
@@ -64,6 +63,8 @@ class VikunjaGlobalState extends State<VikunjaGlobal> {
 
   SettingsManager get settingsManager => new SettingsManager(_storage);
 
+  VersionChecker get versionChecker => new VersionChecker(snackbarKey);
+
   NamespaceService get namespaceService => new NamespaceAPIService(client);
 
   TaskService get taskService => new TaskAPIService(client);
@@ -123,6 +124,7 @@ class VikunjaGlobalState extends State<VikunjaGlobal> {
     platformChannelSpecificsReminders = notifs.NotificationDetails(
         android: androidSpecificsReminders, iOS: iOSSpecifics);
     notificationInitializer();
+    versionChecker.postVersionCheckSnackbar();
 
   }
 

lib/pages/settings.dart

@@ -13,6 +13,7 @@ class SettingsPageState extends State<SettingsPage> {
   List<TaskList>? taskListList;
   int? defaultList;
   bool? ignoreCertificates;
+  String? versionTag, newestVersionTag;
 
   @override
   Widget build(BuildContext context) {
@@ -20,9 +21,10 @@ class SettingsPageState extends State<SettingsPage> {
       VikunjaGlobal.of(context).listService.getAll().then((value) => setState(() => taskListList = value));
     if(defaultList == null)
       VikunjaGlobal.of(context).listService.getDefaultList().then((value) => setState(() => defaultList = value == null ? null : int.tryParse(value)));
-
     if(ignoreCertificates == null)
       VikunjaGlobal.of(context).settingsManager.getIgnoreCertificates().then((value) => setState(() => ignoreCertificates = value == "1" ? true:false));
+    if(versionTag == null)
+      VikunjaGlobal.of(context).versionChecker.getCurrentVersionTag().then((value) => setState(() => versionTag = value));
 
     return new Scaffold(
       appBar: AppBar(title: Text("Settings"),),
@@ -43,7 +45,10 @@ class SettingsPageState extends State<SettingsPage> {
               CheckboxListTile(title: Text("Ignore Certificates"), value: ignoreCertificates, onChanged: (value) {
                 setState(() => ignoreCertificates = value);
                 VikunjaGlobal.of(context).client.reload_ignore_certs(value);
-              }) : ListTile(title: Text("..."))
+              }) : ListTile(title: Text("...")),
+          TextButton(onPressed: () => VikunjaGlobal.of(context).versionChecker.getLatestVersionTag().then((value) => newestVersionTag = value), child: Text("Check for latest version")),
+          Text("Current version: ${versionTag ?? "loading"}"),
+          Text(newestVersionTag != null ? "Newest version: $newestVersionTag" : "")
         ],
       ),
     );

pubspec.yaml

@@ -1,7 +1,7 @@
 name: vikunja_app
 description: Vikunja as Flutter cross platform app
 
-version: 0.0.22-alpha
+version: 0.0.23-alpha
 
 environment:
   sdk: ">=2.12.0 <3.0.0"
@@ -27,6 +27,8 @@ dependencies:
   flutter_colorpicker: ^1.0.3
   flutter_keyboard_visibility: ^5.3.0
   dotted_border: ^2.0.0+2
+  package_info_plus: ^3.0.2
+  url_launcher: ^6.1.7
 
 dev_dependencies:
   flutter_test: