chore: Animated FAB

lib/pages/chat_list/chat_list_view.dart

@@ -69,7 +69,11 @@ class ChatListView extends StatelessWidget {
                     !controller.isSearchMode &&
                         controller.activeSpaceId == null &&
                         !FluffyThemes.isColumnMode(context)
-                    ? StartChatFab()
+                    ? ValueListenableBuilder(
+                        valueListenable: controller.scrolledToTop,
+                        builder: (context, scrolledToTop, _) =>
+                            StartChatFab(extended: scrolledToTop),
+                      )
                     : const SizedBox.shrink(),
               ),
             ),

lib/pages/chat_list/start_chat_fab.dart

@@ -3,22 +3,33 @@
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+import 'package:fluffychat/config/themes.dart';
 import 'package:fluffychat/l10n/l10n.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 
 class StartChatFab extends StatelessWidget {
-  const StartChatFab({super.key});
+  final bool extended;
+  const StartChatFab({this.extended = false, super.key});
 
   @override
   Widget build(BuildContext context) {
-    return FloatingActionButton(
+    return FloatingActionButton.extended(
       heroTag: 'start_chat_fab',
       backgroundColor: Theme.of(context).colorScheme.primary,
       foregroundColor: Theme.of(context).colorScheme.onPrimary,
       onPressed: () => context.go('/rooms/newprivatechat'),
-      tooltip: L10n.of(context).newChat,
-      child: const Icon(Icons.edit_square),
+      extendedIconLabelSpacing: extended ? 10 : 0,
+      extendedPadding: extended
+          ? null
+          : const EdgeInsets.symmetric(horizontal: 16),
+      label: AnimatedSize(
+        alignment: Alignment.centerLeft,
+        duration: FluffyThemes.animationDuration,
+        curve: FluffyThemes.animationCurve,
+        child: extended ? Text(L10n.of(context).newChat) : SizedBox.shrink(),
+      ),
+      icon: const Icon(Icons.edit_square),
     );
   }
 }