Clean up scrollable.dart for 2D (#122357)

Clean up scrollable.dart for 2D

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

@@ -23,7 +23,7 @@ import 'pages.dart';
 import 'performance_overlay.dart';
 import 'restoration.dart';
 import 'router.dart';
-import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'semantics_debugger.dart';
 import 'shared_app_data.dart';
 import 'shortcuts.dart';

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

@@ -9,7 +9,7 @@ import 'package:flutter/services.dart';
 import 'actions.dart';
 import 'focus_traversal.dart';
 import 'framework.dart';
-import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'shortcuts.dart';
 import 'text_editing_intents.dart';
 

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

@@ -35,6 +35,7 @@ import 'scroll_controller.dart';
 import 'scroll_physics.dart';
 import 'scroll_position.dart';
 import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'shortcuts.dart';
 import 'spell_check.dart';
 import 'tap_region.dart';

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

@@ -16,6 +16,7 @@ import 'scroll_controller.dart';
 import 'scroll_physics.dart';
 import 'scroll_view.dart';
 import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'sliver.dart';
 import 'sliver_prototype_extent_list.dart';
 import 'ticker_provider.dart';

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

@@ -11,6 +11,7 @@ import 'framework.dart';
 import 'overscroll_indicator.dart';
 import 'scroll_physics.dart';
 import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'scrollbar.dart';
 
 const Color _kDefaultGlowColor = Color(0xFFFFFFFF);

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

@@ -22,6 +22,7 @@ import 'scroll_metrics.dart';
 import 'scroll_notification.dart';
 import 'scroll_position.dart';
 import 'scrollable.dart';
+import 'scrollable_helpers.dart';
 import 'ticker_provider.dart';
 
 const double _kMinThumbExtent = 18.0;

packages/flutter/lib/widgets.dart

@@ -115,6 +115,7 @@ export 'src/widgets/scroll_position_with_single_context.dart';
 export 'src/widgets/scroll_simulation.dart';
 export 'src/widgets/scroll_view.dart';
 export 'src/widgets/scrollable.dart';
+export 'src/widgets/scrollable_helpers.dart';
 export 'src/widgets/scrollbar.dart';
 export 'src/widgets/selectable_region.dart';
 export 'src/widgets/selection_container.dart';

packages/flutter/test/widgets/scrollable_test.dart

@@ -1690,6 +1690,57 @@ void main() {
     expect(tester.takeException(), isNull);
     semantics.dispose();
   });
+
+  testWidgets('deltaToScrollOrigin getter', (WidgetTester tester) async {
+    await tester.pumpWidget(
+        const MaterialApp(
+          home: CustomScrollView(
+            slivers: <Widget>[
+              SliverToBoxAdapter(child: SizedBox(height: 2000.0)),
+            ],
+          ),
+        )
+    );
+    final TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(Scrollable), warnIfMissed: true), kind: ui.PointerDeviceKind.unknown);
+    expect(getScrollOffset(tester), 0.0);
+    await gesture.moveBy(const Offset(0.0, -200));
+    await tester.pump();
+    await tester.pumpAndSettle();
+
+    expect(getScrollOffset(tester), 200);
+    final ScrollableState scrollable = tester.state(find.byType(Scrollable));
+    expect(scrollable.deltaToScrollOrigin, const Offset(0.0, 200));
+  });
+
+  testWidgets('resolvedPhysics getter', (WidgetTester tester) async {
+    await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData.light().copyWith(
+            platform: TargetPlatform.android,
+          ),
+          home: const CustomScrollView(
+            physics: AlwaysScrollableScrollPhysics(),
+            slivers: <Widget>[
+              SliverToBoxAdapter(child: SizedBox(height: 2000.0)),
+            ],
+          ),
+        )
+    );
+    final TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(Scrollable), warnIfMissed: true), kind: ui.PointerDeviceKind.unknown);
+    expect(getScrollOffset(tester), 0.0);
+    await gesture.moveBy(const Offset(0.0, -200));
+    await tester.pump();
+    await tester.pumpAndSettle();
+
+    expect(getScrollOffset(tester), 200);
+    final ScrollableState scrollable = tester.state(find.byType(Scrollable));
+    String types(ScrollPhysics? value) => value!.parent == null ? '${value.runtimeType}' : '${value.runtimeType} ${types(value.parent)}';
+
+    expect(
+      types(scrollable.resolvedPhysics),
+      'AlwaysScrollableScrollPhysics ClampingScrollPhysics RangeMaintainingScrollPhysics',
+    );
+  });
 }
 
 // ignore: must_be_immutable