feat(designer): dismissable barrier warnings

designer_v2/lib/common_views/form_buttons.dart

@@ -57,11 +57,7 @@ List<Widget> buildFormButtons(FormViewModel formViewModel, FormMode formMode) {
       // enable re-rendering based on form validation status
       builder: (context, form, child) {
         return retainSizeInAppBar(
-          DismissButton(
-            onPressed: () => formViewModel.cancel().then((_) {
-              if (context.mounted) Navigator.maybePop(context);
-            }),
-          ),
+          DismissButton(onPressed: () => Navigator.maybePop(context)),
         );
       },
     ),

designer_v2/lib/common_views/sidesheet/sidesheet.dart

@@ -248,6 +248,7 @@ Future<T?> showModalSideSheet<T extends Object?>({
   String? barrierLabel = "Sidesheet",
   bool useRootNavigator = true,
   RouteSettings? routeSettings,
+  Widget Function(Widget)? wrapRoute,
 }) {
   assert(!barrierDismissible || barrierLabel != null);
   return showGeneralDialog(
@@ -259,16 +260,19 @@ Future<T?> showModalSideSheet<T extends Object?>({
     useRootNavigator: useRootNavigator,
     routeSettings: routeSettings,
     context: context,
-    pageBuilder: (BuildContext context, _, _) => Sidesheet(
-      body: body,
-      tabs: tabs,
-      wrapContent: wrapContent,
-      width: width,
-      withCloseButton: withCloseButton,
-      ignoreAppBar: ignoreAppBar,
-      actionButtons: actionButtons,
-      titleText: title,
-    ),
+    pageBuilder: (BuildContext context, _, _) {
+      final sidesheet = Sidesheet(
+        body: body,
+        tabs: tabs,
+        wrapContent: wrapContent,
+        width: width,
+        withCloseButton: withCloseButton,
+        ignoreAppBar: ignoreAppBar,
+        actionButtons: actionButtons,
+        titleText: title,
+      );
+      return wrapRoute != null ? wrapRoute(sidesheet) : sidesheet;
+    },
     transitionBuilder: (_, animation, _, child) {
       return SlideTransition(
         position: Tween<Offset>(

designer_v2/lib/common_views/sidesheet/sidesheet_form.dart

@@ -1,10 +1,12 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:reactive_forms/reactive_forms.dart';
 import 'package:studyu_designer_v2/common_views/form_buttons.dart';
 import 'package:studyu_designer_v2/common_views/form_scaffold.dart';
 import 'package:studyu_designer_v2/common_views/navbar_tabbed.dart';
 import 'package:studyu_designer_v2/common_views/sidesheet/sidesheet.dart';
 import 'package:studyu_designer_v2/features/forms/form_view_model.dart';
+import 'package:studyu_designer_v2/features/forms/unsaved_changes_dialog.dart';
 import 'package:studyu_designer_v2/theme.dart';
 
 class FormSideSheetTab<T extends FormViewModel> extends NavbarTab {
@@ -20,6 +22,108 @@ class FormSideSheetTab<T extends FormViewModel> extends NavbarTab {
   FormViewBuilder<T> formViewBuilder;
 }
 
+class _FormSidesheetPopEntry<T extends FormViewModel> extends StatefulWidget {
+  const _FormSidesheetPopEntry({
+    required this.formViewModel,
+    required this.child,
+  });
+
+  final T formViewModel;
+  final Widget child;
+
+  @override
+  State<_FormSidesheetPopEntry<T>> createState() =>
+      _FormSidesheetPopEntryState<T>();
+}
+
+class _FormSidesheetPopEntryState<T extends FormViewModel>
+    extends State<_FormSidesheetPopEntry<T>>
+    implements PopEntry {
+  ModalRoute<dynamic>? _route;
+  final ValueNotifier<bool> _canPopNotifier = ValueNotifier(false);
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    _route?.unregisterPopEntry(this);
+    _route = ModalRoute.of(context);
+    debugPrint('[PopEntry] registering with route: ${_route.runtimeType}');
+    _route?.registerPopEntry(this);
+  }
+
+  @override
+  void dispose() {
+    _route?.unregisterPopEntry(this);
+    _route = null;
+    _canPopNotifier.dispose();
+    super.dispose();
+  }
+
+  @override
+  ValueListenable<bool> get canPopNotifier => _canPopNotifier;
+
+  @override
+  void onPopInvokedWithResult(bool didPop, Object? result) {
+    debugPrint(
+      '[PopEntry] onPopInvokedWithResult didPop=$didPop canPop=${_canPopNotifier.value}',
+    );
+    if (didPop) {
+      return;
+    }
+    _handleDismiss();
+  }
+
+  @override
+  void onPopInvoked(bool didPop) {
+    // Deprecated
+  }
+
+  Future<void> _handleDismiss() async {
+    debugPrint(
+      '[PopEntry] _handleDismiss isDirty=${widget.formViewModel.isDirty}',
+    );
+
+    if (!widget.formViewModel.isDirty) {
+      await widget.formViewModel.cancel();
+      if (mounted) {
+        _canPopNotifier.value = true;
+
+        // CHANGE HERE: Wait for the frame to finish so Navigator is unlocked
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (mounted) {
+            Navigator.of(context, rootNavigator: true).pop();
+          }
+        });
+      }
+      return;
+    }
+
+    // Dirty state logic
+    final shouldDiscard = await showDialog<bool>(
+      context: context,
+      barrierColor: ThemeConfig.modalBarrierColor(Theme.of(context)),
+      builder: (context) => const UnsavedChangesDialog(),
+    );
+
+    if (shouldDiscard == true && mounted) {
+      await widget.formViewModel.cancel();
+      if (mounted && Navigator.of(context).canPop()) {
+        _canPopNotifier.value = true;
+
+        // CHANGE HERE: Wait for the frame to finish
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (mounted) {
+            Navigator.of(context, rootNavigator: true).pop();
+          }
+        });
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) => widget.child;
+}
+
 Future<Object?> showFormSideSheet<T extends FormViewModel>({
   required BuildContext context,
   required T formViewModel,
@@ -29,7 +133,7 @@ Future<Object?> showFormSideSheet<T extends FormViewModel>({
   double? width,
   bool withCloseButton = false,
   bool ignoreAppBar = true,
-  bool barrierDismissible = false,
+  bool barrierDismissible = true,
   Color? barrierColor,
 }) {
   barrierColor ??= ThemeConfig.modalBarrierColor(Theme.of(context));
@@ -65,5 +169,7 @@ Future<Object?> showFormSideSheet<T extends FormViewModel>({
     ignoreAppBar: ignoreAppBar,
     barrierDismissible: barrierDismissible,
     barrierColor: barrierColor,
+    wrapRoute: (sidesheet) =>
+        _FormSidesheetPopEntry(formViewModel: formViewModel, child: sidesheet),
   );
 }

designer_v2/lib/features/forms/form_view_model.dart

@@ -65,6 +65,9 @@ abstract class FormViewModel<T> implements IFormGroupController {
     _restoreControlsFromFormData();
     _formModeUpdated();
     _applyValidationSet(validationSet);
+    Future.microtask(() {
+      finalizeInitializationBaseline();
+    });
 
     if (autosave) {
       // Push to event queue to avoid listening to update events
@@ -73,6 +76,11 @@ abstract class FormViewModel<T> implements IFormGroupController {
     }
   }
 
+  void finalizeInitializationBaseline() {
+    prevFormValue = _getFullFormValue();
+    form.markAsPristine();
+  }
+
   T? get formData => _formData;
   set formData(T? formData) => _setFormData(formData);
   T? _formData;
@@ -133,17 +141,10 @@ abstract class FormViewModel<T> implements IFormGroupController {
   /// values are initialized in [setControlsFrom] (controls that are set
   /// programmatically are incorrectly marked as dirty without any user input).
   bool get isDirty {
-    _rememberDefaultControlStates();
-
-    for (final control in form.controls.values) {
-      control.markAsEnabled(emitEvent: false, updateParent: false);
-    }
-    final isEqual = jsonEncode(prevFormValue) == jsonEncode(form.value);
+    if (prevFormValue == null) return false;
 
-    for (final control in form.controls.values) {
-      control.markAsEnabled(emitEvent: false, updateParent: false);
-    }
-    _restoreControlStates(emitEvent: false, updateParent: false);
+    final currentFormValue = _getFullFormValue();
+    final isEqual = jsonEncode(prevFormValue) == jsonEncode(currentFormValue);
 
     return !isEqual;
   }
@@ -169,10 +170,29 @@ abstract class FormViewModel<T> implements IFormGroupController {
   void _setFormData(T? formData) {
     _formData = formData;
     if (formData != null) {
-      setControlsFrom(formData); // update [form] controls automatically
+      setControlsFrom(formData);
     }
-    prevFormValue = {...form.value};
-    form.updateValueAndValidity();
+    finalizeInitializationBaseline();
+  }
+
+  JsonMap _getFullFormValue() {
+    _rememberDefaultControlStates();
+
+    // 1. Temporarily enable all controls
+    for (final control in form.controls.values) {
+      control.markAsEnabled(emitEvent: false, updateParent: false);
+    }
+    // 2. CRITICAL: Force the FormGroup to rebuild its value cache!
+    form.updateValueAndValidity(updateParent: false, emitEvent: false);
+
+    // 3. Deep copy the full value
+    final fullValue = jsonDecode(jsonEncode(form.value)) as JsonMap;
+
+    // 4. Restore original states and rebuild the cache again
+    _restoreControlStates(emitEvent: false, updateParent: false);
+    form.updateValueAndValidity(updateParent: false, emitEvent: false);
+
+    return fullValue;
   }
 
   void _rememberDefaultControlStates() {

designer_v2/lib/features/recruit/invite_code_form_controller.dart

@@ -117,6 +117,7 @@ class InviteCodeFormViewModel extends FormViewModel<StudyInvite> {
   @override
   void initControls() {
     regenerateCode(); // initialize randomly
+    prevFormValue = {...form.value};
   }
 
   // - Validation

flutter_common/lib/envs/.env.dev

@@ -1,5 +1,5 @@
 STUDYU_SUPABASE_URLS=https://studyu-02.dhc-lab.hpi.de
-STUDYU_SUPABASE_PUBLIC_ANON_KEY=eyJhbGciOiAiSFMyNTYiLCJ0eXAiOiAiSldUIn0.eyJyb2xlIjogImFub24iLCJpc3MiOiAic3VwYWJhc2UiLCJpYXQiOiAxNzY1MDEzMTIyLCJleHAiOiAxNzk2NTQ5MTIyfQ.d8cyoFZ_E3ymZyKEjZCP1VktnlMFntOaaosSwjjPFMY
+STUDYU_SUPABASE_PUBLIC_ANON_KEY=eyJhbGciOiAiSFMyNTYiLCJ0eXAiOiAiSldUIn0.eyJyb2xlIjogImFub24iLCJpc3MiOiAic3VwYWJhc2UiLCJpYXQiOiAxNzU3Mzk3MDI5LCJleHAiOiAxNzg4OTMzMDI5fQ.BQwOLCX6h7RBvZ0xTdt2o-3Hw6YJxalI7EuCVwH69yo
 STUDYU_PROJECT_GENERATOR_URL=
 STUDYU_APP_URL=https://app.dev.studyu.health
 STUDYU_DESIGNER_URL=https://designer.dev.studyu.health