Create custom DiagnosticsNode type for DevTools deep links. (#74455)

* Create custom DiagnosticsNode type for DevTools deep links.

packages/flutter/lib/src/widgets/widget_inspector.dart

@@ -1398,11 +1398,11 @@ mixin WidgetInspectorService {
   }
 
   /// Returns a DevTools uri linking to a specific element on the inspector page.
-  String? _devToolsInspectorUriForElement(Object? object) {
+  String? _devToolsInspectorUriForElement(Element element) {
     if (activeDevToolsServerAddress != null && _serviceInfo != null) {
       final Uri? vmServiceUri = _serviceInfo!.serverUri;
       if (vmServiceUri != null) {
-        final String? inspectorRef = toId(object, _consoleObjectGroup);
+        final String? inspectorRef = toId(element, _consoleObjectGroup);
         if (inspectorRef != null) {
           return devToolsInspectorUri(vmServiceUri, inspectorRef);
         }
@@ -2934,8 +2934,9 @@ Iterable<DiagnosticsNode> _describeRelevantUserCode(Element element) {
       final String? devToolsInspectorUri =
           WidgetInspectorService.instance._devToolsInspectorUriForElement(target);
       if (devToolsInspectorUri != null) {
-        devToolsDiagnostic = DiagnosticsNode.message(
+        devToolsDiagnostic = DevToolsDeepLinkProperty(
           'To inspect this widget in Flutter DevTools, visit: $devToolsInspectorUri',
+          devToolsInspectorUri,
         );
       }
 
@@ -2958,6 +2959,27 @@ Iterable<DiagnosticsNode> _describeRelevantUserCode(Element element) {
   return nodes;
 }
 
+
+/// Debugging message for DevTools deep links.
+///
+/// The [value] for this property is a string representation of the Flutter
+/// DevTools url.
+///
+/// Properties `description` and `url` must not be null.
+class DevToolsDeepLinkProperty extends DiagnosticsProperty<String> {
+  /// Creates a diagnostics property that displays a deep link to Flutter DevTools.
+  ///
+  /// The [value] of this property will return a map of data for the Flutter
+  /// DevTools deep link, including the full `url`, the Flutter DevTools `screenId`,
+  /// and the `objectId` in Flutter DevTools that this diagnostic references.
+  ///
+  /// The `description` and `url` arguments must not be null.
+  DevToolsDeepLinkProperty(String description, String url)
+    : assert(description != null),
+      assert(url != null),
+      super('', url, description: description, level: DiagnosticLevel.info);
+}
+
 /// Returns if an object is user created.
 ///
 /// This always returns false if it is not called in debug mode.

packages/flutter/test/widgets/widget_inspector_test.dart

@@ -2835,6 +2835,31 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
         equals('http://127.0.0.1:9100/#/inspector?uri=http%3A%2F%2F127.0.0.1%3A55269%2F798ay5al_FM%3D%2F&inspectorRef=inspector-0'),
       );
     });
+
+    test('DevToolsDeepLinkProperty test', () {
+      final DevToolsDeepLinkProperty node =
+      DevToolsDeepLinkProperty(
+        'description of the deep link',
+        'the-deep-link',
+      );
+      expect(node.toString(), equals('description of the deep link'));
+      expect(node.name, isEmpty);
+      expect(node.value, equals('the-deep-link'));
+      expect(
+        node.toJsonMap(const DiagnosticsSerializationDelegate()),
+        equals(<String, dynamic>{
+          'description': 'description of the deep link',
+          'type': 'DevToolsDeepLinkProperty',
+          'name': '',
+          'style': 'singleLine',
+          'allowNameWrap': true,
+          'missingIfNull': false,
+          'propertyType': 'String',
+          'defaultLevel': 'info',
+          'value': 'the-deep-link',
+        }),
+      );
+    });
   }
 }