lib/components/GravatarImage.dart

@@ -1,46 +0,0 @@
-import 'package:flutter/painting.dart';
-import 'package:crypto/crypto.dart';
-
-class GravatarImageProvider implements NetworkImage {
-  String _email;
-
-  GravatarImageProvider(this._email);
-
-  @override
-  String get url {
-    return "https://secure.gravatar.com/avatar/" +
-        md5.convert(_email.trim().toLowerCase().codeUnits).toString();
-  }
-
-  @override
-  Map<String, String> get headers {
-    // We don't need special headers for our request, so we can just return null here
-    return null;
-  }
-
-  @override
-  ImageStreamCompleter load(NetworkImage key, DecoderCallback decode) {
-    return load(key, decode);
-  }
-
-  @override
-  Future<NetworkImage> obtainKey(ImageConfiguration configuration) {
-    return obtainKey(configuration);
-  }
-
-  @override
-  // Returning null here will set this to 1.0
-  double get scale => null;
-
-  @override
-  Future<bool> evict(
-      {ImageCache cache,
-      ImageConfiguration configuration = ImageConfiguration.empty}) {
-    return evict(cache: cache, configuration: configuration);
-  }
-
-  @override
-  ImageStream resolve(ImageConfiguration configuration) {
-    return resolve(configuration);
-  }
-}

lib/models/user.dart

@@ -1,3 +1,5 @@
+import 'package:crypto/crypto.dart';
+
 class User {
   final int id;
   final String email, username;
@@ -9,6 +11,11 @@ class User {
         username = json['username'];
 
   toJSON() => {"id": this.id, "email": this.email, "username": this.username};
+
+  String avatarUrl() {
+    return "https://secure.gravatar.com/avatar/" +
+        md5.convert((this.email ?? "").trim().toLowerCase().codeUnits).toString();
+  }
 }
 
 class UserTokenPair {

lib/pages/home.dart

@@ -4,7 +4,6 @@ import 'package:flutter/material.dart';
 import 'package:after_layout/after_layout.dart';
 
 import 'package:vikunja_app/components/AddDialog.dart';
-import 'package:vikunja_app/components/GravatarImage.dart';
 import 'package:vikunja_app/pages/namespace/namespace.dart';
 import 'package:vikunja_app/pages/namespace/namespace_edit.dart';
 import 'package:vikunja_app/pages/placeholder.dart';
@@ -90,8 +89,8 @@ class HomePageState extends State<HomePage> with AfterLayoutMixin<HomePage> {
       drawer: new Drawer(
           child: new Column(children: <Widget>[
         new UserAccountsDrawerHeader(
-          accountEmail: currentUser == null ? null : Text(currentUser.email),
-          accountName: currentUser == null ? null : Text(currentUser.username),
+          accountEmail: currentUser?.email == null ? null : Text(currentUser.email),
+          accountName: currentUser?.username == null ? null : Text(currentUser.username),
           onDetailsPressed: () {
             setState(() {
               _showUserDetails = !_showUserDetails;
@@ -100,7 +99,8 @@ class HomePageState extends State<HomePage> with AfterLayoutMixin<HomePage> {
           currentAccountPicture: currentUser == null
               ? null
               : CircleAvatar(
-                  backgroundImage: GravatarImageProvider(currentUser.username)),
+                  backgroundImage: NetworkImage(currentUser.avatarUrl()),
+          ),
           decoration: BoxDecoration(
             image: DecorationImage(
                 image: AssetImage("assets/graphics/hypnotize.png"),