Refactoring: extract dialog scaffold

lib/widget/dialog_scaffold.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+
+/// A Scaffold that can be used with dialogs
+///
+/// Scaffold is needed for [SnackBar] to show correctly on top of a dialog
+class DialogScaffold extends StatelessWidget {
+  const DialogScaffold({
+    Key? key,
+    required this.body,
+    this.canPop = true,
+  }) : super(key: key);
+
+  @override
+  build(BuildContext context) {
+    return GestureDetector(
+      onTap: () {
+        if (canPop) {
+          Navigator.of(context).pop();
+        }
+      },
+      child: WillPopScope(
+        onWillPop: () => Future.value(canPop),
+        child: Scaffold(
+          backgroundColor: Colors.transparent,
+          body: GestureDetector(
+            onTap: () {},
+            child: body,
+          ),
+        ),
+      ),
+    );
+  }
+
+  final Widget body;
+  final bool canPop;
+}

lib/widget/share_album_dialog.dart

@@ -23,6 +23,7 @@ import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/use_case/share_album_with_user.dart';
 import 'package:nc_photos/use_case/unshare_album_with_user.dart';
 import 'package:nc_photos/widget/album_share_outlier_browser.dart';
+import 'package:nc_photos/widget/dialog_scaffold.dart';
 
 class ShareAlbumDialog extends StatefulWidget {
   ShareAlbumDialog({
@@ -54,18 +55,9 @@ class _ShareAlbumDialogState extends State<ShareAlbumDialog> {
 
   @override
   build(BuildContext context) {
-    final canPop = _processingSharee.isEmpty;
     return AppTheme(
-      child: GestureDetector(
+      child: DialogScaffold(
-        onTap: () {
+        canPop: _processingSharee.isEmpty,
-          if (canPop) {
-            Navigator.of(context).pop();
-          }
-        },
-        child: WillPopScope(
-          onWillPop: () => Future.value(canPop),
-          child: Scaffold(
-            backgroundColor: Colors.transparent,
         body: BlocListener<ListShareeBloc, ListShareeBlocState>(
           bloc: _shareeBloc,
           listener: _onShareeStateChange,
@@ -74,21 +66,16 @@ class _ShareAlbumDialogState extends State<ShareAlbumDialog> {
           ),
         ),
       ),
-        ),
-      ),
     );
   }
 
   Widget _buildContent(BuildContext context) {
-    return GestureDetector(
+    return SimpleDialog(
-      onTap: () {},
-      child: SimpleDialog(
       title: Text(L10n.global().shareAlbumDialogTitle),
       children: [
         ..._items.map((i) => _buildItem(context, i)),
         _buildCreateShareItem(context),
       ],
-      ),
     );
   }