Add support for viewing data history after app disconnect (#5509)

packages/devtools_app/lib/src/framework/framework_core.dart

@@ -47,6 +47,7 @@ class FrameworkCore {
     String url, {
     Uri? explicitUri,
     required ErrorReporter errorReporter,
+    bool logException = true,
   }) async {
     if (serviceManager.hasConnection) {
       // TODO(https://github.com/flutter/devtools/issues/1568): why do we call
@@ -68,8 +69,9 @@ class FrameworkCore {
         breakpointManager.initialize();
         return true;
       } catch (e, st) {
-        log('$e\n$st', LogLevel.error);
-
+        if (logException) {
+          log('$e\n$st', LogLevel.error);
+        }
         errorReporter('Unable to connect to VM service at $uri: $e', e);
         return false;
       }

packages/devtools_app/lib/src/framework/initializer.dart

@@ -6,10 +6,12 @@ import 'dart:async';
 
 import 'package:devtools_shared/devtools_shared.dart';
 import 'package:flutter/material.dart';
+import 'package:logging/logging.dart';
 
 import '../shared/analytics/analytics.dart' as ga;
 import '../shared/analytics/constants.dart' as gac;
 import '../shared/common_widgets.dart';
+import '../shared/config_specific/import_export/import_export.dart';
 import '../shared/framework_controller.dart';
 import '../shared/globals.dart';
 import '../shared/primitives/auto_dispose.dart';
@@ -18,6 +20,8 @@ import '../shared/routing.dart';
 import '../shared/theme.dart';
 import 'framework_core.dart';
 
+final _log = Logger('initializer');
+
 /// Widget that requires business logic to be loaded before building its
 /// [builder].
 ///
@@ -78,7 +82,16 @@ class _InitializerState extends State<Initializer>
           !connectionState.userInitiatedConnectionState) {
         // Try to reconnect (otherwise, will fall back to showing the
         // disconnected overlay).
-        unawaited(_attemptUrlConnection());
+        unawaited(
+          _attemptUrlConnection(
+            logException: false,
+            errorReporter: (_, __) {
+              _log.warning(
+                'Attempted to reconnect to the application, but failed.',
+              );
+            },
+          ),
+        );
       }
     });
 
@@ -112,18 +125,25 @@ class _InitializerState extends State<Initializer>
     });
   }
 
-  Future<void> _attemptUrlConnection() async {
+  Future<void> _attemptUrlConnection({
+    ErrorReporter? errorReporter,
+    bool logException = true,
+  }) async {
     if (widget.url == null) {
       _handleNoConnection();
       return;
     }
 
+    errorReporter ??= (String message, Object error) {
+      notificationService.push('$message, $error');
+    };
+
     final uri = normalizeVmServiceUri(widget.url!);
     final connected = await FrameworkCore.initVmService(
       '',
       explicitUri: uri,
-      errorReporter: (message, error) =>
-          notificationService.push('$message, $error'),
+      errorReporter: errorReporter,
+      logException: logException,
     );
 
     if (!connected) {
@@ -155,8 +175,29 @@ class _InitializerState extends State<Initializer>
   }
 
   void hideDisconnectedOverlay() {
-    currentDisconnectedOverlay?.remove();
-    currentDisconnectedOverlay = null;
+    setState(() {
+      currentDisconnectedOverlay?.remove();
+      currentDisconnectedOverlay = null;
+    });
+  }
+
+  void _reviewHistory() {
+    assert(offlineController.offlineDataJson.isNotEmpty);
+
+    offlineController.enterOfflineMode(
+      offlineApp: offlineController.previousConnectedApp!,
+    );
+    hideDisconnectedOverlay();
+    final args = <String, String?>{
+      'uri': null,
+      'screen': offlineController
+          .offlineDataJson[DevToolsExportKeys.activeScreenId.name] as String
+    };
+    final routerDelegate = DevToolsRouterDelegate.of(context);
+    Router.neglect(
+      context,
+      () => routerDelegate.navigate(snapshotPageId, args),
+    );
   }
 
   OverlayEntry _createDisconnectedOverlay() {
@@ -187,11 +228,12 @@ class _InitializerState extends State<Initializer>
                   style: theme.textTheme.bodyMedium,
                 ),
               const Spacer(),
-              ElevatedButton(
-                onPressed: hideDisconnectedOverlay,
-                child: const Text('Review History'),
-              ),
-              const SizedBox(height: defaultSpacing),
+              if (offlineController.offlineDataJson.isNotEmpty)
+                ElevatedButton(
+                  onPressed: _reviewHistory,
+                  child: const Text('Review recent data (offline)'),
+                ),
+              const Spacer(),
             ],
           ),
         ),
@@ -202,7 +244,7 @@ class _InitializerState extends State<Initializer>
 
   @override
   Widget build(BuildContext context) {
-    return _checkLoaded()
+    return _checkLoaded() || offlineController.offlineMode.value
         ? widget.builder(context)
         : Scaffold(
             body: currentDisconnectedOverlay != null

packages/devtools_app/lib/src/screens/performance/performance_controller.dart

@@ -102,6 +102,8 @@ class PerformanceController extends DisposableController
 
   Future<void> _initHelper() async {
     initData();
+    initReviewHistoryOnDisconnectListener();
+
     await _applyToFeatureControllersAsync((c) => c.init());
     if (!offlineController.offlineMode.value) {
       await serviceManager.onServiceAvailable;

packages/devtools_app/lib/src/screens/performance/performance_model.dart

@@ -147,9 +147,9 @@ class PerformanceData {
         flutterFramesKey: frames.map((frame) => frame.json).toList(),
         displayRefreshRateKey: displayRefreshRate,
         traceEventsKey: traceEvents,
-        selectedEventKey: selectedEvent?.json ?? {},
-        cpuProfileKey: cpuProfileData?.toJson ?? {},
-        rasterStatsKey: rasterStats?.json ?? {},
+        selectedEventKey: selectedEvent?.json ?? <String, dynamic>{},
+        cpuProfileKey: cpuProfileData?.toJson ?? <String, dynamic>{},
+        rasterStatsKey: rasterStats?.json ?? <String, dynamic>{},
         rebuildCountModelKey: rebuildCountModel.toJson(),
       };
 }

packages/devtools_app/lib/src/screens/profiler/panes/method_table/method_table_controller.dart

@@ -23,6 +23,7 @@ class MethodTableController extends DisposableController
   MethodTableController({
     required ValueListenable<CpuProfileData?> dataNotifier,
   }) {
+    createMethodTableGraph(dataNotifier.value);
     addAutoDisposeListener(dataNotifier, () {
       createMethodTableGraph(dataNotifier.value);
     });
@@ -44,12 +45,11 @@ class MethodTableController extends DisposableController
     reset();
     if (cpuProfileData == null ||
         cpuProfileData == CpuProfilerController.baseStateCpuProfileData ||
-        cpuProfileData == CpuProfilerController.emptyAppStartUpProfile) {
+        cpuProfileData == CpuProfilerController.emptyAppStartUpProfile ||
+        !cpuProfileData.processed) {
       return;
     }
 
-    assert(cpuProfileData.processed);
-
     List<CpuStackFrame> profileRoots = cpuProfileData.callTreeRoots;
     // For a profile rooted at tags, treat it as if it is not. Otherwise, the
     // tags will show up in the method table.

packages/devtools_app/lib/src/screens/profiler/profiler_screen_controller.dart

@@ -37,6 +37,7 @@ class ProfilerScreenController extends DisposableController
   }
 
   Future<void> _initHelper() async {
+    initReviewHistoryOnDisconnectListener();
     if (!offlineController.offlineMode.value) {
       await allowedError(
         serviceManager.service!.setProfilePeriod(mediumProfilePeriod),
@@ -45,7 +46,11 @@ class ProfilerScreenController extends DisposableController
 
       _currentIsolate = serviceManager.isolateManager.selectedIsolate.value;
       addAutoDisposeListener(serviceManager.isolateManager.selectedIsolate, () {
-        switchToIsolate(serviceManager.isolateManager.selectedIsolate.value);
+        final selectedIsolate =
+            serviceManager.isolateManager.selectedIsolate.value;
+        if (selectedIsolate != null) {
+          switchToIsolate(selectedIsolate);
+        }
       });
 
       addAutoDisposeListener(preferences.vmDeveloperModeEnabled, () async {

packages/devtools_app/lib/src/service/service_manager.dart

@@ -361,6 +361,14 @@ class ServiceConnectionManager {
   void vmServiceClosed({
     ConnectedState connectionState = const ConnectedState(false),
   }) {
+    // Set [offlineController.previousConnectedApp] in case we need it for
+    // viewing data after disconnect. This must be done before resetting the
+    // rest of the service manager state.
+    final previousConnectedApp = connectedApp != null
+        ? OfflineConnectedApp.parse(connectedApp!.toJson())
+        : null;
+    offlineController.previousConnectedApp = previousConnectedApp;
+
     _serviceAvailable = Completer();
 
     service = null;

packages/devtools_app/lib/src/shared/config_specific/import_export/import_export.dart

@@ -78,9 +78,8 @@ class ImportController {
                 <String, Object>{})
             .cast<String, Object>();
     offlineController
-      ..enterOfflineMode()
+      ..enterOfflineMode(offlineApp: OfflineConnectedApp.parse(connectedApp))
       ..offlineDataJson = devToolsSnapshot;
-    serviceManager.connectedApp = OfflineConnectedApp.parse(connectedApp);
     notificationService.push(attemptingToImportMessage(activeScreenId));
     _pushSnapshotScreenForImport(activeScreenId);
   }
@@ -147,25 +146,34 @@ abstract class ExportController {
     required String fileName,
   });
 
-  String encode(Map<String, dynamic> contents) {
-    final activeScreenId = contents[DevToolsExportKeys.activeScreenId.name];
-    final _contents = {
+  Map<String, dynamic> generateDataForExport({
+    required Map<String, dynamic> offlineScreenData,
+    ConnectedApp? connectedApp,
+  }) {
+    final contents = {
       DevToolsExportKeys.devToolsSnapshot.name: true,
-      DevToolsExportKeys.activeScreenId.name: activeScreenId,
       DevToolsExportKeys.devToolsVersion.name: version,
       DevToolsExportKeys.connectedApp.name:
-          serviceManager.connectedApp!.toJson(),
+          connectedApp?.toJson() ?? serviceManager.connectedApp!.toJson(),
+      ...offlineScreenData,
     };
+    final activeScreenId = contents[DevToolsExportKeys.activeScreenId.name];
+
     // This is a workaround to guarantee that DevTools exports are compatible
     // with other trace viewers (catapult, perfetto, chrome://tracing), which
     // require a top level field named "traceEvents".
     if (activeScreenId == ScreenMetaData.performance.id) {
       final traceEvents = List<Map<String, dynamic>>.from(
-        contents[traceEventsFieldName],
+        contents[activeScreenId][traceEventsFieldName],
       );
-      _contents[traceEventsFieldName] = traceEvents;
-      contents.remove(traceEventsFieldName);
+      contents[traceEventsFieldName] = traceEvents;
+      contents[activeScreenId].remove(traceEventsFieldName);
     }
-    return jsonEncode(_contents..addAll({activeScreenId: contents}));
+    return contents;
+  }
+
+  String encode(Map<String, dynamic> offlineScreenData) {
+    final data = generateDataForExport(offlineScreenData: offlineScreenData);
+    return jsonEncode(data);
   }
 }

packages/devtools_app/lib/src/shared/connected_app.dart

@@ -217,7 +217,7 @@ class OfflineConnectedApp extends ConnectedApp {
     this.operatingSystem = ConnectedApp._unknownOS,
   });
 
-  factory OfflineConnectedApp.parse(Map<String, Object>? json) {
+  factory OfflineConnectedApp.parse(Map<String, Object?>? json) {
     if (json == null) return OfflineConnectedApp();
     return OfflineConnectedApp(
       isFlutterAppNow: json[ConnectedApp.isFlutterAppKey] as bool?,

packages/devtools_app/lib/src/shared/offline_mode.dart

@@ -10,6 +10,7 @@ import 'config_specific/import_export/import_export.dart';
 import 'connected_app.dart';
 import 'globals.dart';
 import 'primitives/auto_dispose.dart';
+import 'routing.dart';
 
 class OfflineModeController {
   bool get isOffline => _offlineMode.value;
@@ -30,8 +31,9 @@ class OfflineModeController {
         offlineDataJson[screenId] != null;
   }
 
-  void enterOfflineMode() {
+  void enterOfflineMode({required ConnectedApp offlineApp}) {
     previousConnectedApp = serviceManager.connectedApp;
+    serviceManager.connectedApp = offlineApp;
     _offlineMode.value = true;
   }
 
@@ -71,6 +73,32 @@ mixin OfflineScreenControllerMixin<T> on AutoDisposeControllerMixin {
     final encodedData = _exportController.encode(screenDataForExport().json);
     _exportController.downloadFile(encodedData);
   }
+
+  /// Adds a listener that will prepare the screen's current data for offline
+  /// viewing after an app disconnect.
+  ///
+  /// This is in preparation for the user clicking the 'Review History' button
+  /// from the disconnect screen.
+  void initReviewHistoryOnDisconnectListener() {
+    addAutoDisposeListener(serviceManager.connectedState, () {
+      final connectionState = serviceManager.connectedState.value;
+      if (!connectionState.connected &&
+          !connectionState.userInitiatedConnectionState) {
+        final currentScreenData = screenDataForExport();
+        // Only store data for the current page. We can change this in the
+        // future if we support offline imports for more than once screen at a
+        // time.
+        if (DevToolsRouterDelegate.currentPage == currentScreenData.screenId) {
+          final previouslyConnectedApp = offlineController.previousConnectedApp;
+          final offlineData = _exportController.generateDataForExport(
+            offlineScreenData: currentScreenData.json,
+            connectedApp: previouslyConnectedApp,
+          );
+          offlineController.offlineDataJson = offlineData;
+        }
+      }
+    });
+  }
 }
 
 class OfflineScreenData {
@@ -82,6 +110,6 @@ class OfflineScreenData {
 
   Map<String, Object?> get json => {
         DevToolsExportKeys.activeScreenId.name: screenId,
-        ...data,
+        screenId: data,
       };
 }

packages/devtools_app/lib/src/shared/routing.dart

@@ -124,6 +124,9 @@ class DevToolsRouterDelegate extends RouterDelegate<DevToolsRouteConfiguration>
   @override
   final GlobalKey<NavigatorState> navigatorKey;
 
+  static String get currentPage => _currentPage;
+  static late String _currentPage;
+
   final Page Function(
     BuildContext,
     String?,
@@ -222,6 +225,7 @@ class DevToolsRouterDelegate extends RouterDelegate<DevToolsRouteConfiguration>
 
   /// Replaces the navigation stack with a new route.
   void _replaceStack(DevToolsRouteConfiguration configuration) {
+    _currentPage = configuration.page;
     routes
       ..clear()
       ..add(configuration);

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -11,6 +11,9 @@ Dart & Flutter DevTools - A Suite of Performance Tools for Dart and Flutter
 * Added the new verbose logging feature for helping us debug user issues. [#5404](https://github.com/flutter/devtools/pull/5404)
     ![verbose logging](images/verbose-logging.png "verbose_logging")
 * Fix a bug where some asynchronous errors were not being reported. [#5456](https://github.com/flutter/devtools/pull/5456)
+* Added support for viewing data after an app disconnects for screens that
+support offline viewing (currently only the Performance and CPU proiler pages).
+[#5509](https://github.com/flutter/devtools/pull/5509)
 
 ## Inspector updates
 TODO: Remove this section if there are not any general updates.

packages/devtools_app/test/performance/controls/performance_controls_test.dart

@@ -92,7 +92,9 @@ void main() {
 
     testWidgetsWithWindowSize('builds for offline mode', windowSize,
         (WidgetTester tester) async {
-      offlineController.enterOfflineMode();
+      offlineController.enterOfflineMode(
+        offlineApp: serviceManager.connectedApp!,
+      );
       await _pumpControls(tester);
       expect(find.byType(ExitOfflineButton), findsOneWidget);
       expect(find.byType(VisibilityButton), findsOneWidget);