Rename SliverFill to SliverFillViewport and add SliverFillRemaining (#9194)

packages/flutter/lib/rendering.dart

@@ -50,6 +50,7 @@ export 'src/rendering/rotated_box.dart';
 export 'src/rendering/semantics.dart';
 export 'src/rendering/shifted_box.dart';
 export 'src/rendering/sliver.dart';
+export 'src/rendering/sliver_fill.dart';
 export 'src/rendering/sliver_fixed_extent_list.dart';
 export 'src/rendering/sliver_grid.dart';
 export 'src/rendering/sliver_list.dart';

packages/flutter/lib/src/rendering/sliver.dart

@@ -412,7 +412,7 @@ class SliverConstraints extends Constraints {
              'scrollOffset: ${scrollOffset.toStringAsFixed(1)}, '
              'remainingPaintExtent: ${remainingPaintExtent.toStringAsFixed(1)}, ' +
              (overlap != 0.0 ? 'overlap: ${overlap.toStringAsFixed(1)}, ' : '') +
-             'crossAxisExtent: ${crossAxisExtent.toStringAsFixed(1)}' +
+             'crossAxisExtent: ${crossAxisExtent.toStringAsFixed(1)}, ' +
              'viewportMainAxisExtent: ${viewportMainAxisExtent.toStringAsFixed(1)}' +
            ')';
   }
@@ -1218,19 +1218,19 @@ abstract class RenderSliverHelpers implements RenderSliver {
 // ADAPTER FOR RENDER BOXES INSIDE SLIVERS
 // Transitions from the RenderSliver world to the RenderBox world.
 
-/// A [RenderSliver] that contains a single [RenderBox].
-///
-/// The child will not be laid out if it is not visible.
+/// An abstract class for [RenderSliver]s that contains a single [RenderBox].
 ///
 /// See also:
 ///
 /// * [RenderSliver], which explains more about the Sliver protocol.
 /// * [RenderBox], which explains more about the Box protocol.
-/// * [RenderViewport], which allows [RenderSliver] objects to be placed inside
-///   a [RenderBox] (the opposite of this class).
-class RenderSliverToBoxAdapter extends RenderSliver with RenderObjectWithChildMixin<RenderBox>, RenderSliverHelpers {
+/// * [RenderSliverToBoxAdapter], which extends this class to size the child
+///   according to its preferred size.
+/// * [RenderSliverFillRemaining], which extends this class to size the child
+///   to fill the remaining space in the viewport.
+abstract class RenderSliverSingleBoxAdapter extends RenderSliver with RenderObjectWithChildMixin<RenderBox>, RenderSliverHelpers {
   /// Creates a [RenderSliver] that wraps a [RenderBox].
-  RenderSliverToBoxAdapter({
+  RenderSliverSingleBoxAdapter({
     RenderBox child,
   }) {
     this.child = child;
@@ -1242,34 +1242,7 @@ class RenderSliverToBoxAdapter extends RenderSliver with RenderObjectWithChildMi
       child.parentData = new SliverPhysicalParentData();
   }
 
-  @override
-  void performLayout() {
-    if (child == null) {
-      geometry = SliverGeometry.zero;
-      return;
-    }
-    child.layout(constraints.asBoxConstraints(), parentUsesSize: true);
-    double childExtent;
-    switch (constraints.axis) {
-      case Axis.horizontal:
-        childExtent = child.size.width;
-        break;
-      case Axis.vertical:
-        childExtent = child.size.height;
-        break;
-    }
-    assert(childExtent != null);
-    final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: childExtent);
-    assert(paintedChildSize.isFinite);
-    assert(paintedChildSize >= 0.0);
-    geometry = new SliverGeometry(
-      scrollExtent: childExtent,
-      paintExtent: paintedChildSize,
-      maxPaintExtent: childExtent,
-      hitTestExtent: paintedChildSize,
-      hasVisualOverflow: childExtent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
-    );
-
+  void setChildParentData(RenderObject child, SliverConstraints constraints, SliverGeometry geometry) {
     final SliverPhysicalParentData childParentData = child.parentData;
     assert(constraints.axisDirection != null);
     assert(constraints.growthDirection != null);
@@ -1321,3 +1294,52 @@ class RenderSliverToBoxAdapter extends RenderSliver with RenderObjectWithChildMi
 
   // TODO(ianh): semantics - shouldn't walk the invisible children
 }
+
+/// A [RenderSliver] that contains a single [RenderBox].
+///
+/// The child will not be laid out if it is not visible. It is sized according
+/// to the child's preferences in the main axis, and with a tight constraint
+/// forcing it to the dimensions of the viewport in the cross axis.
+///
+/// See also:
+///
+/// * [RenderSliver], which explains more about the Sliver protocol.
+/// * [RenderBox], which explains more about the Box protocol.
+/// * [RenderViewport], which allows [RenderSliver] objects to be placed inside
+///   a [RenderBox] (the opposite of this class).
+class RenderSliverToBoxAdapter extends RenderSliverSingleBoxAdapter {
+  /// Creates a [RenderSliver] that wraps a [RenderBox].
+  RenderSliverToBoxAdapter({
+    RenderBox child,
+  }) : super(child: child);
+
+  @override
+  void performLayout() {
+    if (child == null) {
+      geometry = SliverGeometry.zero;
+      return;
+    }
+    child.layout(constraints.asBoxConstraints(), parentUsesSize: true);
+    double childExtent;
+    switch (constraints.axis) {
+      case Axis.horizontal:
+        childExtent = child.size.width;
+        break;
+      case Axis.vertical:
+        childExtent = child.size.height;
+        break;
+    }
+    assert(childExtent != null);
+    final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: childExtent);
+    assert(paintedChildSize.isFinite);
+    assert(paintedChildSize >= 0.0);
+    geometry = new SliverGeometry(
+      scrollExtent: childExtent,
+      paintExtent: paintedChildSize,
+      maxPaintExtent: childExtent,
+      hitTestExtent: paintedChildSize,
+      hasVisualOverflow: childExtent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
+    );
+    setChildParentData(child, constraints, geometry);
+  }
+}

packages/flutter/lib/src/rendering/sliver_fill.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:math' as math;
+
+import 'package:flutter/foundation.dart';
+
+import 'box.dart';
+import 'sliver.dart';
+import 'sliver_fixed_extent_list.dart';
+import 'sliver_multi_box_adaptor.dart';
+
+/// A sliver that contains multiple box children that each fill the viewport.
+///
+/// [RenderSliverFillViewport] places its children in a linear array along the
+/// main axis. Each child is sized to fill the viewport, both in the main and
+/// cross axis. A [viewportFraction] factor can be provided to size the children
+/// to a multiple of the viewport's main axis dimension (typically a fraction
+/// less than 1.0).
+///
+/// See also:
+///
+///  * [RenderSliverFillRemaining], which sizes the children based on the
+///    remaining space rather than the viewport itself.
+///  * [RenderSliverFixedExtentList], which has a configurable [itemExtent].
+///  * [RenderSliverList], which does not require its children to have the same
+///  * /// extent in the main axis.
+class RenderSliverFillViewport extends RenderSliverFixedExtentBoxAdaptor {
+  /// Creates a sliver that contains multiple box children that each fill the
+  /// viewport.
+  ///
+  /// The [childManager] argument must not be null.
+  RenderSliverFillViewport({
+    @required RenderSliverBoxChildManager childManager,
+    double viewportFraction: 1.0,
+  }) : _viewportFraction = viewportFraction, super(childManager: childManager) {
+    assert(viewportFraction != null);
+    assert(viewportFraction > 0.0);
+  }
+
+  @override
+  double get itemExtent => constraints.viewportMainAxisExtent * viewportFraction;
+
+  /// The fraction of the viewport that each child should fill in the main axis.
+  ///
+  /// If this fraction is less than 1.0, more than one child will be visible at
+  /// once. If this fraction is greater than 1.0, each child will be larger than
+  /// the viewport in the main axis.
+  double get viewportFraction => _viewportFraction;
+  double _viewportFraction;
+  set viewportFraction(double value) {
+    assert(value != null);
+    if (_viewportFraction == value)
+      return;
+    _viewportFraction = value;
+    markNeedsLayout();
+  }
+
+  double get _padding => (1.0 - viewportFraction) * constraints.viewportMainAxisExtent * 0.5;
+
+  @override
+  double indexToLayoutOffset(double itemExtent, int index) {
+    return _padding + super.indexToLayoutOffset(itemExtent, index);
+  }
+
+  @override
+  int getMinChildIndexForScrollOffset(double scrollOffset, double itemExtent) {
+    return super.getMinChildIndexForScrollOffset(math.max(scrollOffset - _padding, 0.0), itemExtent);
+  }
+
+  @override
+  int getMaxChildIndexForScrollOffset(double scrollOffset, double itemExtent) {
+    return super.getMaxChildIndexForScrollOffset(math.max(scrollOffset - _padding, 0.0), itemExtent);
+  }
+
+  @override
+  double estimateMaxScrollOffset(SliverConstraints constraints, {
+    int firstIndex,
+    int lastIndex,
+    double leadingScrollOffset,
+    double trailingScrollOffset,
+  }) {
+    final double padding = _padding;
+    return childManager.estimateMaxScrollOffset(
+      constraints,
+      firstIndex: firstIndex,
+      lastIndex: lastIndex,
+      leadingScrollOffset: leadingScrollOffset - padding,
+      trailingScrollOffset: trailingScrollOffset - padding,
+    ) + padding + padding;
+  }
+}
+
+/// A sliver that contains a single box child that fills the remaining space in
+/// the viewport.
+///
+/// [RenderSliverFillRemaining] sizes its child to fill the viewport in the
+/// cross axis and to fill the remaining space in the viewport in the main axis.
+///
+/// Typically this will be the last sliver in a viewport, since (by definition)
+/// there is never any room for anything beyond this sliver.
+///
+/// See also:
+///
+///  * [RenderSliverFillViewport], which sizes its children based on the
+///    size of the viewport, regardless of what else is in the scroll view.
+///  * [RenderSliverList], which shows a list of variable-sized children in a
+///    viewport.
+class RenderSliverFillRemaining extends RenderSliverSingleBoxAdapter {
+  /// Creates a [RenderSliver] that wraps a [RenderBox] which is sized to fit
+  /// the remaining space in the viewport.
+  RenderSliverFillRemaining({
+    RenderBox child,
+  }) : super(child: child);
+
+  @override
+  void performLayout() {
+    final double size = constraints.remainingPaintExtent - math.min(constraints.overlap, 0.0);
+    if (child != null)
+      child.layout(constraints.asBoxConstraints(minExtent: size, maxExtent: size), parentUsesSize: true);
+    final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: size);
+    assert(paintedChildSize.isFinite);
+    assert(paintedChildSize >= 0.0);
+    geometry = new SliverGeometry(
+      scrollExtent: constraints.viewportMainAxisExtent,
+      paintExtent: paintedChildSize,
+      maxPaintExtent: paintedChildSize,
+      hasVisualOverflow: size > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
+    );
+    if (child != null)
+      setChildParentData(child, constraints, geometry);
+  }
+}

packages/flutter/lib/src/rendering/sliver_fixed_extent_list.dart

@@ -28,8 +28,10 @@ import 'sliver_multi_box_adaptor.dart';
 /// See also:
 ///
 ///  * [RenderSliverFixedExtentList], which has a configurable [itemExtent].
-///  * [RenderSliverFill], which determines the [itemExtent] based on
+///  * [RenderSliverFillViewport], which determines the [itemExtent] based on
 ///    [SliverConstraints.viewportMainAxisExtent].
+///  * [RenderSliverFillRemaining], which determines the [itemExtent] based on
+///    [SliverConstraints.remainingPaintExtent].
 ///  * [RenderSliverList], which does not require its children to have the same
 ///    extent in the main axis.
 abstract class RenderSliverFixedExtentBoxAdaptor extends RenderSliverMultiBoxAdaptor {
@@ -225,10 +227,12 @@ abstract class RenderSliverFixedExtentBoxAdaptor extends RenderSliverMultiBoxAda
 ///
 /// See also:
 ///
-///  * [RenderSliverFill], which determines the [itemExtent] based on
-///    [SliverConstraints.viewportMainAxisExtent].
 ///  * [RenderSliverList], which does not require its children to have the same
 ///    extent in the main axis.
+///  * [RenderSliverFillViewport], which determines the [itemExtent] based on
+///    [SliverConstraints.viewportMainAxisExtent].
+///  * [RenderSliverFillRemaining], which determines the [itemExtent] based on
+///    [SliverConstraints.remainingPaintExtent].
 class RenderSliverFixedExtentList extends RenderSliverFixedExtentBoxAdaptor {
   /// Creates a sliver that contains multiple box children that have a given
   /// extent in the main axis.
@@ -250,80 +254,3 @@ class RenderSliverFixedExtentList extends RenderSliverFixedExtentBoxAdaptor {
     markNeedsLayout();
   }
 }
-
-/// A sliver that contains a multiple box children that each fill the viewport.
-///
-/// [RenderSliverFill] places its children in a linear array along the main
-/// axis. Each child is sized to fill the viewport, both in the main and cross
-/// axis.
-///
-/// See also:
-///
-///  * [RenderSliverFixedExtentList], which has a configurable [itemExtent].
-///  * [RenderSliverList], which does not require its children to have the same
-///    extent in the main axis.
-class RenderSliverFill extends RenderSliverFixedExtentBoxAdaptor {
-  /// Creates a sliver that contains a multiple box children that each fill the
-  /// viewport.
-  ///
-  /// The [childManager] argument must not be null.
-  RenderSliverFill({
-    @required RenderSliverBoxChildManager childManager,
-    double viewportFraction: 1.0,
-  }) : _viewportFraction = viewportFraction, super(childManager: childManager) {
-    assert(viewportFraction != null);
-    assert(viewportFraction > 0.0);
-  }
-
-  @override
-  double get itemExtent => constraints.viewportMainAxisExtent * viewportFraction;
-
-  /// The fraction of the viewport that each child should fill in the main axis.
-  ///
-  /// If this fraction is less than 1.0, more than one child will be visible at
-  /// once. If this fraction is greater than 1.0, each child will be larger than
-  /// the viewport in the main axis.
-  double get viewportFraction => _viewportFraction;
-  double _viewportFraction;
-  set viewportFraction(double value) {
-    assert(value != null);
-    if (_viewportFraction == value)
-      return;
-    _viewportFraction = value;
-    markNeedsLayout();
-  }
-
-  double get _padding => (1.0 - viewportFraction) * constraints.viewportMainAxisExtent * 0.5;
-
-  @override
-  double indexToLayoutOffset(double itemExtent, int index) {
-    return _padding + super.indexToLayoutOffset(itemExtent, index);
-  }
-
-  @override
-  int getMinChildIndexForScrollOffset(double scrollOffset, double itemExtent) {
-    return super.getMinChildIndexForScrollOffset(math.max(scrollOffset - _padding, 0.0), itemExtent);
-  }
-
-  @override
-  int getMaxChildIndexForScrollOffset(double scrollOffset, double itemExtent) {
-    return super.getMaxChildIndexForScrollOffset(math.max(scrollOffset - _padding, 0.0), itemExtent);
-  }
-
-  @override
-  double estimateMaxScrollOffset(SliverConstraints constraints, {
-    int firstIndex,
-    int lastIndex,
-    double leadingScrollOffset,
-    double trailingScrollOffset,
-  }) {
-    final double padding = _padding;
-    return childManager.estimateMaxScrollOffset(
-      constraints,
-      firstIndex: firstIndex,
-      lastIndex: lastIndex,
-      leadingScrollOffset: leadingScrollOffset - padding,
-      trailingScrollOffset: trailingScrollOffset - padding,
-    ) + padding + padding;
-  }
-}

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

@@ -426,7 +426,7 @@ class _PageViewState extends State<PageView> {
             axisDirection: axisDirection,
             offset: offset,
             slivers: <Widget>[
-              new SliverFill(
+              new SliverFillViewport(
                 viewportFraction: config.controller.viewportFraction,
                 delegate: config.childrenDelegate
               ),

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

@@ -334,7 +334,7 @@ class SliverList extends SliverMultiBoxAdaptorWidget {
 ///
 /// See also:
 ///
-///  * [SliverFill], which determines the [itemExtent] based on
+///  * [SliverFillViewport], which determines the [itemExtent] based on
 ///    [SliverConstraints.viewportMainAxisExtent].
 ///  * [SliverList], which does not require its children to have the same
 ///    extent in the main axis.
@@ -416,17 +416,18 @@ class SliverGrid extends SliverMultiBoxAdaptorWidget {
 
 /// A sliver that contains a multiple box children that each fill the viewport.
 ///
-/// [SliverFill] places its children in a linear array along the main axis. Each
-/// child is sized to fill the viewport, both in the main and cross axis.
+/// [SliverFillViewport] places its children in a linear array along the main
+/// axis. Each child is sized to fill the viewport, both in the main and cross
+/// axis.
 ///
 /// See also:
 ///
 ///  * [SliverFixedExtentList], which has a configurable [itemExtent].
 ///  * [SliverList], which does not require its children to have the same
 ///    extent in the main axis.
-class SliverFill extends SliverMultiBoxAdaptorWidget {
+class SliverFillViewport extends SliverMultiBoxAdaptorWidget {
   /// Creates a sliver whose box children that each fill the viewport.
-  SliverFill({
+  SliverFillViewport({
     Key key,
     @required SliverChildDelegate delegate,
     this.viewportFraction: 1.0,
@@ -443,13 +444,13 @@ class SliverFill extends SliverMultiBoxAdaptorWidget {
   final double viewportFraction;
 
   @override
-  RenderSliverFill createRenderObject(BuildContext context) {
+  RenderSliverFillViewport createRenderObject(BuildContext context) {
     final SliverMultiBoxAdaptorElement element = context;
-    return new RenderSliverFill(childManager: element, viewportFraction: viewportFraction);
+    return new RenderSliverFillViewport(childManager: element, viewportFraction: viewportFraction);
   }
 
   @override
-  void updateRenderObject(BuildContext context, RenderSliverFill renderObject) {
+  void updateRenderObject(BuildContext context, RenderSliverFillViewport renderObject) {
     renderObject.viewportFraction = viewportFraction;
   }
 }
@@ -675,3 +676,28 @@ class SliverMultiBoxAdaptorElement extends RenderObjectElement implements Render
     _childElements.values.toList().forEach(visitor);
   }
 }
+
+/// A sliver that contains a single box child that fills the remaining space in
+/// the viewport.
+///
+/// [SliverFillRemaining] sizes its child to fill the viewport in the cross axis
+/// and to fill the remaining space in the viewport in the main axis.
+///
+/// Typically this will be the last sliver in a viewport, since (by definition)
+/// there is never any room for anything beyond this sliver.
+///
+/// See also:
+///
+///  * [SliverFillViewport], which sizes its children based on the
+///    size of the viewport, regardless of what else is in the scroll view.
+///  * [SliverList], which shows a list of variable-sized children in a
+///    viewport.
+class SliverFillRemaining extends SingleChildRenderObjectWidget {
+  SliverFillRemaining({
+    Key key,
+    Widget child,
+  }) : super(key: key, child: child);
+
+  @override
+  RenderSliverFillRemaining createRenderObject(BuildContext context) => new RenderSliverFillRemaining();
+}

packages/flutter/test/widgets/sliver_fill_remaining_test.dart

@@ -6,43 +6,54 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/widgets.dart';
 
 void main() {
-  testWidgets('SliverFillRemaining control test', (WidgetTester tester) async {
-    final List<Widget> children = new List<Widget>.generate(20, (int i) {
-      return new Container(child: new Text('$i'));
-    });
-
+  testWidgets('SliverFillRemaining - no siblings', (WidgetTester tester) async {
+    final ScrollController controller = new ScrollController();
     await tester.pumpWidget(
       new CustomScrollView(
+        controller: controller,
         slivers: <Widget>[
-          new SliverFill(
-            delegate: new SliverChildListDelegate(children),
-          ),
+          new SliverFillRemaining(child: new Container()),
         ],
       ),
     );
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(600.0));
 
-    final RenderBox box = tester.renderObject<RenderBox>(find.byType(Container).first);
-    expect(box.size.height, equals(600.0));
+    controller.jumpTo(50.0);
+    await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(600.0));
 
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-    expect(find.text('2'), findsNothing);
+    controller.jumpTo(-100.0);
+    await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(600.0));
 
-    await tester.drag(find.byType(Scrollable), const Offset(0.0, -700.0));
+    controller.jumpTo(0.0);
     await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(600.0));
+  });
 
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
-    expect(find.text('2'), findsOneWidget);
-    expect(find.text('3'), findsNothing);
-    expect(find.text('4'), findsNothing);
+  testWidgets('SliverFillRemaining - one sibling', (WidgetTester tester) async {
+    final ScrollController controller = new ScrollController();
+    await tester.pumpWidget(
+      new CustomScrollView(
+        controller: controller,
+        slivers: <Widget>[
+          new SliverToBoxAdapter(child: new SizedBox(height: 100.0)),
+          new SliverFillRemaining(child: new Container()),
+        ],
+      ),
+    );
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(500.0));
 
-    await tester.drag(find.byType(Scrollable), const Offset(0.0, 200.0));
+    controller.jumpTo(50.0);
     await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(550.0));
 
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsOneWidget);
-    expect(find.text('2'), findsNothing);
-    expect(find.text('3'), findsNothing);
+    controller.jumpTo(-100.0);
+    await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(400.0)); // (!)
+
+    controller.jumpTo(0.0);
+    await tester.pump();
+    expect(tester.renderObject<RenderBox>(find.byType(Container)).size.height, equals(500.0));
   });
 }

packages/flutter/test/widgets/sliver_fill_viewport_test.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter/widgets.dart';
+
+void main() {
+  testWidgets('SliverFillRemaining control test', (WidgetTester tester) async {
+    final List<Widget> children = new List<Widget>.generate(20, (int i) {
+      return new Container(child: new Text('$i'));
+    });
+
+    await tester.pumpWidget(
+      new CustomScrollView(
+        slivers: <Widget>[
+          new SliverFillViewport(
+            delegate: new SliverChildListDelegate(children),
+          ),
+        ],
+      ),
+    );
+
+    final RenderBox box = tester.renderObject<RenderBox>(find.byType(Container).first);
+    expect(box.size.height, equals(600.0));
+
+    expect(find.text('0'), findsOneWidget);
+    expect(find.text('1'), findsNothing);
+    expect(find.text('2'), findsNothing);
+
+    await tester.drag(find.byType(Scrollable), const Offset(0.0, -700.0));
+    await tester.pump();
+
+    expect(find.text('0'), findsNothing);
+    expect(find.text('1'), findsOneWidget);
+    expect(find.text('2'), findsOneWidget);
+    expect(find.text('3'), findsNothing);
+    expect(find.text('4'), findsNothing);
+
+    await tester.drag(find.byType(Scrollable), const Offset(0.0, 200.0));
+    await tester.pump();
+
+    expect(find.text('0'), findsOneWidget);
+    expect(find.text('1'), findsOneWidget);
+    expect(find.text('2'), findsNothing);
+    expect(find.text('3'), findsNothing);
+
+    await tester.drag(find.byType(Scrollable), const Offset(0.0, 700.0));
+    await tester.pump();
+
+    final RenderBox box2 = tester.renderObject<RenderBox>(find.byType(Container).first);
+    expect(box2.size.height, equals(600.0));
+
+    expect(find.text('0'), findsOneWidget);
+    expect(find.text('1'), findsNothing);
+    expect(find.text('2'), findsNothing);
+    expect(find.text('3'), findsNothing);
+  });
+}