Add a setting to enable auto-refreshing the inspector tree (#8483)

packages/devtools_app/lib/src/screens/inspector_shared/inspector_settings_dialog.dart

@@ -48,8 +48,17 @@ class FlutterInspectorSettingsDialog extends StatelessWidget {
                       'Hovering over any widget displays its properties and values.',
                   gaItem: gac.inspectorHoverEvalMode,
                 ),
-                if (!inspectorV2Enabled) ...[
-                  const SizedBox(height: largeSpacing),
+                const SizedBox(height: largeSpacing),
+                if (inspectorV2Enabled) ...[
+                  CheckboxSetting(
+                    notifier: preferences.inspector.autoRefreshEnabled
+                        as ValueNotifier<bool?>,
+                    title: 'Enable auto-refreshing of the widget tree',
+                    description:
+                        'The widget tree will automatically be refreshed after a hot-reload.',
+                    gaItem: gac.inspectorAutoRefreshEnabled,
+                  ),
+                ] else ...[
                   const InspectorDefaultDetailsViewOption(),
                 ],
                 const SizedBox(height: largeSpacing),

packages/devtools_app/lib/src/screens/inspector_v2/inspector_controller.dart

@@ -23,6 +23,8 @@ import 'package:logging/logging.dart';
 import 'package:vm_service/vm_service.dart';
 
 import '../../service/service_extensions.dart' as extensions;
+import '../../shared/analytics/analytics.dart' as ga;
+import '../../shared/analytics/constants.dart' as gac;
 import '../../shared/console/eval/inspector_tree_v2.dart';
 import '../../shared/console/primitives/simple_items.dart';
 import '../../shared/diagnostics/diagnostics_node.dart';
@@ -130,6 +132,17 @@ class InspectorController extends DisposableController
     }
 
     serviceConnection.consoleService.ensureServiceInitialized();
+
+    final vmService = serviceConnection.serviceManager.service;
+    if (vmService != null) {
+      autoDisposeStreamSubscription(
+        vmService.onIsolateEvent.listen(_maybeAutoRefreshInspector),
+      );
+
+      autoDisposeStreamSubscription(
+        vmService.onExtensionEvent.listen(_maybeAutoRefreshInspector),
+      );
+    }
   }
 
   void _handleConnectionStart() {
@@ -368,6 +381,26 @@ class InspectorController extends DisposableController
     return _waitForPendingUpdateDone();
   }
 
+  Future<void> refreshInspector() async {
+    // If the user is force refreshing the inspector before the first load has
+    // completed, this could indicate a slow load time or that the inspector
+    // failed to load the tree once available.
+    if (!firstInspectorTreeLoadCompleted) {
+      // We do not want to complete this timing operation because the force
+      // refresh will skew the results.
+      ga.cancelTimingOperation(
+        InspectorScreen.id,
+        gac.pageReady,
+      );
+      ga.select(
+        gac.inspector,
+        gac.refreshEmptyTree,
+      );
+      firstInspectorTreeLoadCompleted = true;
+    }
+    await onForceRefresh();
+  }
+
   void filterErrors() {
     serviceConnection.errorBadgeManager.filterErrors(
       InspectorScreen.id,
@@ -417,6 +450,27 @@ class InspectorController extends DisposableController
     }
   }
 
+  bool _receivedIsolateReloadEvent = false;
+
+  Future<void> _maybeAutoRefreshInspector(Event event) async {
+    if (!preferences.inspector.autoRefreshEnabled.value) return;
+
+    // It is not sufficent to wait for the isolate reload event, because Flutter
+    // might not have re-painted the app. Instead, we need to wait for the first
+    // frame AFTER the isolate reload event in order to request the new tree.
+    if (event.kind == EventKind.kExtension) {
+      if (!_receivedIsolateReloadEvent) return;
+      if (event.extensionKind == 'Flutter.Frame') {
+        _receivedIsolateReloadEvent = false;
+        await refreshInspector();
+      }
+    }
+
+    if (event.kind == EventKind.kIsolateReload) {
+      _receivedIsolateReloadEvent = true;
+    }
+  }
+
   Future<void> _recomputeTreeRoot(
     RemoteDiagnosticsNode? newSelection, {
     bool? hideImplementationWidgets,
@@ -451,8 +505,9 @@ class InspectorController extends DisposableController
         expandChildren: true,
       );
       inspectorTree.root = rootNode;
-
-      refreshSelection(newSelection);
+      final selectedNode =
+          _determineNewSelection(newSelection ?? selectedDiagnostic);
+      refreshSelection(selectedNode);
       _implementationWidgetsHidden.value = hideImplementationWidgets;
     } catch (error, st) {
       _log.shout(error, error, st);
@@ -461,6 +516,77 @@ class InspectorController extends DisposableController
     }
   }
 
+  RemoteDiagnosticsNode? _determineNewSelection(
+    RemoteDiagnosticsNode? previousSelection,
+  ) {
+    if (previousSelection == null) return null;
+    if (valueToInspectorTreeNode.containsKey(previousSelection.valueRef)) {
+      return previousSelection;
+    }
+
+    // TODO(https://github.com/flutter/devtools/issues/8481): Consider using a
+    // variation of a path-finding algorithm to determine the new selection,
+    // instead of looking for the first matching descendant.
+    final (closestUnchangedAncestor, distanceToAncestor) =
+        _findClosestUnchangedAncestor(previousSelection);
+    if (closestUnchangedAncestor == null) return inspectorTree.root?.diagnostic;
+
+    const distanceOffset = 3;
+    final matchingDescendant = _findMatchingDescendant(
+      of: closestUnchangedAncestor,
+      matching: previousSelection,
+      inRange: Range(
+        distanceToAncestor - distanceOffset,
+        distanceToAncestor + distanceOffset,
+      ),
+    );
+
+    return matchingDescendant ?? closestUnchangedAncestor;
+  }
+
+  (RemoteDiagnosticsNode?, int) _findClosestUnchangedAncestor(
+    RemoteDiagnosticsNode node, [
+    int distanceToAncestor = 1,
+  ]) {
+    final inspectorTreeNode = valueToInspectorTreeNode[node.valueRef];
+    if (inspectorTreeNode != null) {
+      return (inspectorTreeNode.diagnostic, distanceToAncestor);
+    }
+
+    final ancestor = node.parent;
+    if (ancestor == null) return (null, distanceToAncestor);
+    return _findClosestUnchangedAncestor(ancestor, distanceToAncestor++);
+  }
+
+  RemoteDiagnosticsNode? _findMatchingDescendant({
+    required RemoteDiagnosticsNode of,
+    required RemoteDiagnosticsNode matching,
+    required Range inRange,
+    int currentDistance = 1,
+  }) {
+    if (currentDistance > inRange.end) return null;
+
+    if (inRange.contains(currentDistance)) {
+      if (of.description == matching.description) {
+        return of;
+      }
+    }
+
+    final children = of.childrenNow;
+    final distance = currentDistance++;
+    for (final child in children) {
+      final matchingDescendant = _findMatchingDescendant(
+        of: child,
+        matching: matching,
+        inRange: inRange,
+        currentDistance: distance,
+      );
+      if (matchingDescendant != null) return matchingDescendant;
+    }
+
+    return null;
+  }
+
   Future<void> toggleImplementationWidgetsVisibility() async {
     final root = inspectorTree.root?.diagnostic;
     if (root != null) {
@@ -512,7 +638,7 @@ class InspectorController extends DisposableController
     final matchingNode = findMatchingInspectorTreeNode(newSelection);
     if (matchingNode != null) {
       setSelectedNode(matchingNode);
-      syncSelectionHelper(selection: newSelection);
+      syncSelectionHelper(selection: matchingNode.diagnostic);
 
       syncTreeSelection();
     }

packages/devtools_app/lib/src/screens/inspector_v2/inspector_screen_body.dart

@@ -212,23 +212,7 @@ class InspectorScreenBodyState extends State<InspectorScreenBody>
     ga.select(gac.inspector, gac.refresh);
     unawaited(
       blockWhileInProgress(() async {
-        // If the user is force refreshing the inspector before the first load has
-        // completed, this could indicate a slow load time or that the inspector
-        // failed to load the tree once available.
-        if (!controller.firstInspectorTreeLoadCompleted) {
-          // We do not want to complete this timing operation because the force
-          // refresh will skew the results.
-          ga.cancelTimingOperation(
-            InspectorScreen.id,
-            gac.pageReady,
-          );
-          ga.select(
-            gac.inspector,
-            gac.refreshEmptyTree,
-          );
-          controller.firstInspectorTreeLoadCompleted = true;
-        }
-        await controller.onForceRefresh();
+        await controller.refreshInspector();
       }),
     );
   }

packages/devtools_app/lib/src/shared/analytics/constants.dart

@@ -122,6 +122,7 @@ const wasm = 'wasm';
 const verboseLogging = 'verboseLogging';
 const inspectorHoverEvalMode = 'inspectorHoverEvalMode';
 const inspectorV2Enabled = 'inspectorV2Enabled';
+const inspectorAutoRefreshEnabled = 'inspectorAutoRefreshEnabled';
 const clearLogs = 'clearLogs';
 const copyLogs = 'copyLogs';
 

packages/devtools_app/lib/src/shared/preferences/_inspector_preferences.dart

@@ -20,6 +20,7 @@ class InspectorPreferencesController extends DisposableController
     with AutoDisposeControllerMixin {
   ValueListenable<bool> get hoverEvalModeEnabled => _hoverEvalMode;
   ValueListenable<bool> get inspectorV2Enabled => _inspectorV2Enabled;
+  ValueListenable<bool> get autoRefreshEnabled => _autoRefreshEnabled;
   ValueListenable<InspectorDetailsViewType> get defaultDetailsView =>
       _defaultDetailsView;
   ListValueNotifier<String> get pubRootDirectories => _pubRootDirectories;
@@ -30,6 +31,9 @@ class InspectorPreferencesController extends DisposableController
 
   final _hoverEvalMode = ValueNotifier<bool>(false);
   final _inspectorV2Enabled = ValueNotifier<bool>(false);
+  // TODO(https://github.com/flutter/devtools/issues/1423): Default to true
+  // after verifying auto-refreshes are performant.
+  final _autoRefreshEnabled = ValueNotifier<bool>(false);
   final _pubRootDirectories = ListValueNotifier<String>([]);
   final _pubRootDirectoriesAreBusy = ValueNotifier<bool>(false);
   final _busyCounter = ValueNotifier<int>(0);
@@ -39,6 +43,7 @@ class InspectorPreferencesController extends DisposableController
 
   static const _hoverEvalModeStorageId = 'inspector.hoverEvalMode';
   static const _inspectorV2EnabledStorageId = 'inspector.inspectorV2Enabled';
+  static const _autoRefreshEnabledStorageId = 'inspector.autoRefreshEnabled';
   static const _defaultDetailsViewStorageId =
       'inspector.defaultDetailsViewType';
   static const _customPubRootDirectoriesStoragePrefix =
@@ -62,6 +67,7 @@ class InspectorPreferencesController extends DisposableController
   Future<void> init() async {
     await _initHoverEvalMode();
     await _initInspectorV2Enabled();
+    await _initAutoRefreshEnabled();
     // TODO(jacobr): consider initializing this first as it is not blocking.
     _initPubRootDirectories();
     await _initDefaultInspectorDetailsView();
@@ -83,6 +89,14 @@ class InspectorPreferencesController extends DisposableController
     );
   }
 
+  Future<void> _initAutoRefreshEnabled() async {
+    await _updateAutoRefreshEnabled();
+    _saveBooleanPreferenceChanges(
+      preferenceStorageId: _autoRefreshEnabledStorageId,
+      preferenceNotifier: _autoRefreshEnabled,
+    );
+  }
+
   Future<void> _updateHoverEvalMode() async {
     await _updateBooleanPreference(
       preferenceStorageId: _hoverEvalModeStorageId,
@@ -99,6 +113,16 @@ class InspectorPreferencesController extends DisposableController
     );
   }
 
+  Future<void> _updateAutoRefreshEnabled() async {
+    await _updateBooleanPreference(
+      preferenceStorageId: _autoRefreshEnabledStorageId,
+      preferenceNotifier: _autoRefreshEnabled,
+      // TODO(https://github.com/flutter/devtools/issues/1423): Default to true
+      // after verifying auto-refreshes are performant.
+      defaultValue: false,
+    );
+  }
+
   void _saveBooleanPreferenceChanges({
     required String preferenceStorageId,
     required ValueNotifier<bool> preferenceNotifier,
@@ -421,6 +445,11 @@ class InspectorPreferencesController extends DisposableController
     _inspectorV2Enabled.value = inspectorV2Enabled;
   }
 
+  @visibleForTesting
+  void setAutoRefreshEnabled(bool autoRefreshEnabled) {
+    _autoRefreshEnabled.value = autoRefreshEnabled;
+  }
+
   void setDefaultInspectorDetailsView(InspectorDetailsViewType value) {
     _defaultDetailsView.value = value;
   }

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -16,7 +16,8 @@ To learn more about DevTools, check out the
 
 ## Inspector updates
 
-TODO: Remove this section if there are not any general updates.
+- Added an option to the [new Inspector's](https://docs.flutter.dev/tools/devtools/release-notes/release-notes-2.40.1#inspector-updates)
+  settings to allow auto-refreshing the widget tree after a hot-reload. - [#8483](https://github.com/flutter/devtools/pull/8483)
 
 ## Performance updates