design: Nicer loading screen and empty page

lib/pages/views/empty_page_view.dart

@@ -1,12 +1,36 @@
+import 'dart:math';
+
 import 'package:flutter/material.dart';
 
 class EmptyPage extends StatelessWidget {
-  const EmptyPage({Key key}) : super(key: key);
+  final bool loading;
+  static const double _width = 200;
+  const EmptyPage({this.loading = false, Key key}) : super(key: key);
   @override
   Widget build(BuildContext context) {
+    final _width = min(MediaQuery.of(context).size.width, EmptyPage._width);
     return Scaffold(
-      body: Center(
-        child: Image.asset('assets/favicon.png', width: 100, height: 100),
+      body: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Center(
+            child: Hero(
+              tag: 'info-logo',
+              child: Image.asset(
+                'assets/info-logo.png',
+                width: _width,
+                height: _width,
+              ),
+            ),
+          ),
+          if (loading)
+            Center(
+              child: SizedBox(
+                width: _width,
+                child: LinearProgressIndicator(),
+              ),
+            ),
+        ],
       ),
     );
   }