[Inspector V2] Handle selection of an implementation widget in the app (#8494)

diff --git a/packages/devtools_app/lib/src/screens/inspector_v2/inspector_controller.dart b/packages/devtools_app/lib/src/screens/inspector_v2/inspector_controller.dart
index 76aeedf..468154f 100644
--- a/packages/devtools_app/lib/src/screens/inspector_v2/inspector_controller.dart
+++ b/packages/devtools_app/lib/src/screens/inspector_v2/inspector_controller.dart

@@ -603,6 +603,25 @@
 
     try {
       final newSelection = await pendingSelectionFuture;
+
+      // Show an error and don't update the selected node in the tree if the
+      // user selected an implementation widget in the app while implementation
+      // widgets are hidden in the tree.
+      if (implementationWidgetsHidden.value && newSelection != null) {
+        final isInTree =
+            valueToInspectorTreeNode.containsKey(newSelection.valueRef);
+        final hasParent = newSelection.parent != null;
+        final isImplementationWidget = !isInTree && !hasParent;
+        if (isImplementationWidget) {
+          notificationService.pushError(
+            'Selected an implementation widget. Please toggle "Show Implementation Widgets" and select a widget from the device again.',
+            allowDuplicates: true,
+            isReportable: false,
+          );
+          return;
+        }
+      }
+
       if (_disposed || group.disposed) return;
 
       selectionGroups.promoteNext();
@@ -650,6 +669,19 @@
 
     _updateSelectedErrorFromNode(_selectedNode.value);
     unawaited(_loadPropertiesForNode(_selectedNode.value));
+
+    /// If the user selects a hidden implementation widget, first expand that
+    /// widget's hideable group before scrolling.
+    final diagnostic = _selectedNode.value?.diagnostic;
+    if (diagnostic != null && diagnostic.isHidden) {
+      inspectorTree.refreshTree(
+        updateTreeAction: () {
+          diagnostic.hideableGroupLeader?.toggleHiddenGroup();
+          return true;
+        },
+      );
+    }
+
     animateTo(selectedNode.value);
   }
 

diff --git a/packages/devtools_app/lib/src/shared/notifications.dart b/packages/devtools_app/lib/src/shared/notifications.dart
index e613438..943e1b9 100644
--- a/packages/devtools_app/lib/src/shared/notifications.dart
+++ b/packages/devtools_app/lib/src/shared/notifications.dart

@@ -71,6 +71,7 @@
     String? reportExplanation,
     bool isDismissible = true,
     bool isReportable = true,
+    bool allowDuplicates = false,
   }) {
     final reportErrorAction = NotificationAction(
       label: 'Report error',
@@ -105,7 +106,7 @@
             ? NotificationMessage.defaultDuration * 2
             : NotificationMessage.defaultDuration,
       ),
-      allowDuplicates: false,
+      allowDuplicates: allowDuplicates,
     );
   }
 

diff --git a/packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md b/packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md
index b6e2bb9..94ab92b 100644
--- a/packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md
+++ b/packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -43,6 +43,7 @@
 
   ![New inspector opt-in setting](images/new_inspector.png "DevTools setting to opt into the new Flutter Inspector.")
 - Fixed an [issue](https://github.com/flutter/devtools/issues/8487) where the [new Inspector](https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.40.1#inspector-updates) would not load after a hot-restart in the legacy Inspector. - [#8491](https://github.com/flutter/devtools/pull/8491)
+- Fixed an [issue](https://github.com/flutter/devtools/issues/8465) preventing scrolling to an implementation widget in the [new Inspector](https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.40.1#inspector-updates) after selecting it on the device. - [#8494](https://github.com/flutter/devtools/pull/8494)
 
 ## Performance updates