prevent pageView scrolling when calling ensureVisible (#67988)

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

@@ -341,17 +341,9 @@ class _PagePosition extends ScrollPositionWithSingleContext implements PageMetri
     RenderObject? targetRenderObject,
   }) {
     // Since the _PagePosition is intended to cover the available space within
-    // its viewport, stop trying to move the target render object to the center
+    // its viewport, stop trying to any scroll, otherwise, could end up changing
-    // - otherwise, could end up changing which page is visible and moving the
+    // which page is visible and moving the render object out of the viewport.
-    // targetRenderObject out of the viewport.
+    return Future<void>.value();
-    return super.ensureVisible(
-      object,
-      alignment: alignment,
-      duration: duration,
-      curve: curve,
-      alignmentPolicy: alignmentPolicy,
-      targetRenderObject: null,
-    );
   }
 
   @override

packages/flutter/test/widgets/scrollable_test.dart

@@ -1006,6 +1006,76 @@ void main() {
     expect(targetMidRightPage1, findsOneWidget);
     expect(targetMidLeftPage1, findsOneWidget);
   });
+
+  testWidgets('ensureVisible does not move PageViews when there are objects between pageView and target object', (WidgetTester tester) async {
+    final PageController controller = PageController();
+    int count = 0;
+
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: PageView(
+          controller: controller,
+          children: List<Widget>.generate(3, (int index) {
+            return Row(
+              children: <Widget>[
+                Container(
+                  width: 400,
+                  color: Colors.red,
+                ),
+                Expanded(
+                  child: Container(
+                    color: Colors.green,
+                    width: double.infinity,
+                    height: 50,
+                    child: SingleChildScrollView(
+                      scrollDirection: Axis.horizontal,
+                      child: Container(
+                        key: Key(index.toString()),
+                        color: Colors.yellow,
+                        height: 50,
+                        width: 200,
+                      ),
+                    ),
+                  ),
+                )
+              ],
+            );
+          }),
+        ),
+      ),
+    );
+
+    controller.position.addListener(() {
+      count++;
+    });
+
+    final Finder targetOfPage0 = find.byKey(const Key('0'));
+    final Finder targetOfPage1 = find.byKey(const Key('1'));
+
+    expect(targetOfPage0, findsOneWidget);
+    expect(targetOfPage1, findsNothing);
+
+    // `ensureVisible` should not trigger any scrolling or page changing of pageView.
+    await tester.ensureVisible(targetOfPage0);
+    await tester.pumpAndSettle();
+    expect(count, 0);
+    expect(targetOfPage0, findsOneWidget);
+    expect(targetOfPage1, findsNothing);
+
+    controller.jumpToPage(1);
+    await tester.pumpAndSettle();
+
+    expect(count, 1); // Trigger by `controller.jumpToPage(1)`
+    expect(targetOfPage0, findsNothing);
+    expect(targetOfPage1, findsOneWidget);
+
+    await tester.ensureVisible(targetOfPage1);
+    await tester.pumpAndSettle();
+    expect(count, 1);
+    expect(targetOfPage0, findsNothing);
+    expect(targetOfPage1, findsOneWidget);
+  });
 }
 
 // ignore: must_be_immutable