fix: Popup menu without elevation

lib/widgets/chat_settings_popup_menu.dart

@@ -14,6 +14,7 @@ import 'package:vrouter/vrouter.dart';
 import 'package:fluffychat/pages/chat/cupertino_widgets_bottom_sheet.dart';
 import 'package:fluffychat/pages/chat/edit_widgets_dialog.dart';
 import 'package:fluffychat/pages/chat/widgets_bottom_sheet.dart';
+import 'm2_popup_menu_button.dart';
 import 'matrix.dart';
 
 class ChatSettingsPopupMenu extends StatefulWidget {
@@ -125,7 +126,7 @@ class ChatSettingsPopupMenuState extends State<ChatSettingsPopupMenu> {
           onKeysPressed: _showWidgets,
           child: Container(),
         ),
-        PopupMenuButton(
+        M2PopupMenuButton(
           onSelected: (String choice) async {
             switch (choice) {
               case 'widgets':

lib/widgets/log_view.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 
 import 'package:matrix/matrix.dart';
 
+import 'm2_popup_menu_button.dart';
+
 class LogViewer extends StatefulWidget {
   const LogViewer({Key? key}) : super(key: key);
 
@@ -32,7 +34,7 @@ class LogViewerState extends State<LogViewer> {
             icon: const Icon(Icons.zoom_out_outlined),
             onPressed: () => setState(() => fontSize--),
           ),
-          PopupMenuButton<Level>(
+          M2PopupMenuButton<Level>(
             itemBuilder: (context) => Level.values
                 .map((level) => PopupMenuItem(
                       value: level,

lib/widgets/m2_popup_menu_button.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/material.dart';
+
+class M2PopupMenuButton<T> extends StatelessWidget {
+  final List<PopupMenuEntry<T>> Function(BuildContext) itemBuilder;
+  final T? initialValue;
+  final void Function(T)? onSelected;
+  final void Function()? onCanceled;
+  final Widget? icon;
+  final Color? color;
+  final Widget? child;
+
+  const M2PopupMenuButton({
+    Key? key,
+    required this.itemBuilder,
+    this.initialValue,
+    this.onSelected,
+    this.onCanceled,
+    this.icon,
+    this.color,
+    this.child,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    return Theme(
+      data: theme.copyWith(
+        useMaterial3: false,
+        popupMenuTheme: PopupMenuThemeData(
+          color: theme.colorScheme.surface,
+          elevation: theme.appBarTheme.scrolledUnderElevation,
+          textStyle: theme.textTheme.bodyText1,
+        ),
+      ),
+      child: PopupMenuButton<T>(
+        itemBuilder: itemBuilder,
+        initialValue: initialValue,
+        onSelected: onSelected,
+        onCanceled: onCanceled,
+        icon: icon,
+        color: color,
+        child: child,
+      ),
+    );
+  }
+}