Bug fix where MouseScrollWheel zoom in flutter-web does not execute...

Bug fix where MouseScrollWheel zoom in flutter-web does not execute onInteraction functions (#65313)

AUTHORS

@@ -65,3 +65,4 @@ CaiJingLong <cjl_spy@163.com>
 Alex Li <google@alexv525.com>
 Ram Navan <hiramprasad@gmail.com>
 meritozh <ah841814092@gmail.com>
+Terrence Addison Tandijono(flotilla) <terrenceaddison32@gmail.com>

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

@@ -746,6 +746,7 @@ class _InteractiveViewerState extends State<InteractiveViewer> with TickerProvid
         rotation: details.rotation,
       ));
     }
+
     final Offset focalPointScene = _transformationController.toScene(
       details.localFocalPoint,
     );
@@ -918,6 +919,22 @@ class _InteractiveViewerState extends State<InteractiveViewer> with TickerProvid
         _transformationController.value,
         focalPointSceneScaled - focalPointScene,
       );
+      if (widget.onInteractionStart != null) {
+        widget.onInteractionStart(
+            ScaleStartDetails(focalPoint: focalPointSceneScaled)
+        );
+      }
+      if (widget.onInteractionUpdate != null) {
+        widget.onInteractionUpdate(ScaleUpdateDetails(
+          rotation: 0.0,
+          scale: scaleChange,
+          horizontalScale: 1.0,
+          verticalScale: 1.0,
+        ));
+      }
+      if (widget.onInteractionEnd != null) {
+        widget.onInteractionEnd(ScaleEndDetails());
+      }
     }
   }
 

packages/flutter/test/widgets/interactive_viewer_test.dart

@@ -623,6 +623,46 @@ void main() {
       expect(transformationController.value.getMaxScaleOnAxis(), equals(1.0));
     });
 
+    testWidgets('Scale with mouse returns onInteraction properties', (WidgetTester tester) async{
+      final TransformationController transformationController = TransformationController();
+      double scaleChange;
+      Velocity currentVelocity;
+      bool calledStart;
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: Center(
+              child: InteractiveViewer(
+                transformationController: transformationController,
+                onInteractionStart: (ScaleStartDetails details){
+                  calledStart = true;
+                },
+                onInteractionUpdate: (ScaleUpdateDetails details){
+                  scaleChange = details.scale;
+                },
+                onInteractionEnd: (ScaleEndDetails details){
+                  currentVelocity = details.velocity;
+                },
+                child: Container(width: 200.0, height: 200.0),
+              ),
+            ),
+          ),
+        ),
+      );
+
+      final Offset center = tester.getCenter(find.byType(InteractiveViewer));
+      await scrollAt(center, tester, const Offset(0.0, -20.0));
+      await tester.pumpAndSettle();
+      const Velocity noMovement = Velocity(pixelsPerSecond: Offset(0,0));
+      final double afterScaling = transformationController.value.getMaxScaleOnAxis();
+
+      expect(scaleChange,greaterThan(1.0));
+      expect(afterScaling, isNot(equals(null)));
+      expect(afterScaling, isNot(equals(1.0)));
+      expect(currentVelocity, equals(noMovement));
+      expect(calledStart, equals(true));
+    });
+
     testWidgets('viewport changes size', (WidgetTester tester) async {
       final TransformationController transformationController = TransformationController();
       await tester.pumpWidget(