feat: New chat background colors and chatlist design

lib/pages/chat_list.dart

@@ -51,6 +51,17 @@ class ChatListController extends State<ChatList> {
 
   String _activeSpaceId;
   String get activeSpaceId => _activeSpaceId;
+  final ScrollController scrollController = ScrollController();
+  bool scrolledToTop = true;
+
+  void _onScroll() {
+    final newScrolledToTop = scrollController.position.pixels <= 0;
+    if (newScrolledToTop != scrolledToTop) {
+      setState(() {
+        scrolledToTop = newScrolledToTop;
+      });
+    }
+  }
 
   void setActiveSpaceId(BuildContext context, String spaceId) {
     Scaffold.of(context).openEndDrawer();
@@ -156,6 +167,7 @@ class ChatListController extends State<ChatList> {
     WidgetsBinding.instance.addPostFrameCallback(
       (_) => waitForFirstSync().then((_) => checkBootstrap()),
     );
+    scrollController.addListener(_onScroll);
     super.initState();
   }
 
@@ -181,6 +193,7 @@ class ChatListController extends State<ChatList> {
     _intentDataStreamSubscription?.cancel();
     _intentFileStreamSubscription?.cancel();
     _intentUriStreamSubscription?.cancel();
+    scrollController.removeListener(_onScroll);
     super.dispose();
   }
 

lib/pages/views/chat_list_view.dart

@@ -31,6 +31,7 @@ class ChatListView extends StatelessWidget {
             },
             child: Scaffold(
               appBar: AppBar(
+                elevation: controller.scrolledToTop ? 0 : null,
                 actionsIconTheme: IconThemeData(
                   color: controller.selectedRoomIds.isEmpty
                       ? null
@@ -200,12 +201,20 @@ class ChatListView extends StatelessWidget {
                 Expanded(child: _ChatListViewBody(controller)),
               ]),
               floatingActionButton: selectMode == SelectMode.normal
-                  ? FloatingActionButton(
-                      heroTag: 'main_fab',
-                      onPressed: () =>
-                          VRouter.of(context).to('/newprivatechat'),
-                      child: Icon(CupertinoIcons.chat_bubble),
-                    )
+                  ? controller.scrolledToTop
+                      ? FloatingActionButton.extended(
+                          heroTag: 'main_fab',
+                          onPressed: () =>
+                              VRouter.of(context).to('/newprivatechat'),
+                          icon: Icon(CupertinoIcons.chat_bubble),
+                          label: Text(L10n.of(context).newChat),
+                        )
+                      : FloatingActionButton(
+                          heroTag: 'main_fab',
+                          onPressed: () =>
+                              VRouter.of(context).to('/newprivatechat'),
+                          child: Icon(CupertinoIcons.chat_bubble),
+                        )
                   : null,
               drawer: controller.spaces.isEmpty
                   ? null
@@ -307,6 +316,7 @@ class _ChatListViewBody extends StatelessWidget {
                 );
               }
               return ListView.builder(
+                controller: controller.scrollController,
                 itemCount: rooms.length,
                 itemBuilder: (BuildContext context, int i) {
                   return ChatListItem(

lib/pages/views/chat_view.dart

@@ -2,6 +2,7 @@ import 'dart:ui';
 
 import 'package:emoji_picker_flutter/emoji_picker_flutter.dart';
 import 'package:fluffychat/config/app_config.dart';
+import 'package:fluffychat/widgets/background_gradient_box.dart';
 import 'package:matrix/matrix.dart';
 import 'package:fluffychat/pages/chat.dart';
 import 'package:fluffychat/widgets/avatar.dart';
@@ -204,6 +205,7 @@ class ChatView extends StatelessWidget {
               : null,
           body: Stack(
             children: <Widget>[
+              BackgroundGradientBox(),
               if (Matrix.of(context).wallpaper != null)
                 Image.file(
                   Matrix.of(context).wallpaper,

lib/pages/views/empty_page_view.dart

@@ -1,5 +1,6 @@
 import 'dart:math';
 
+import 'package:fluffychat/widgets/background_gradient_box.dart';
 import 'package:flutter/material.dart';
 
 class EmptyPage extends StatelessWidget {
@@ -10,26 +11,31 @@ class EmptyPage extends StatelessWidget {
   Widget build(BuildContext context) {
     final _width = min(MediaQuery.of(context).size.width, EmptyPage._width);
     return Scaffold(
-      body: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
+      body: Stack(
         children: [
-          Center(
-            child: Hero(
-              tag: 'info-logo',
-              child: Image.asset(
-                'assets/info-logo.png',
-                width: _width,
-                height: _width,
+          BackgroundGradientBox(),
+          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(),
+                  ),
+                ),
+            ],
           ),
-          if (loading)
-            Center(
-              child: SizedBox(
-                width: _width,
-                child: LinearProgressIndicator(),
-              ),
-            ),
         ],
       ),
     );