Add SingleChildScrollView (#7620)

This widget is a replacement for ScrollableViewport that uses the new
Scrollable2 machinery. The widget is not based on Slivers but does use the new
scroll behavior classes.

examples/flutter_gallery/lib/demo/expansion_panels_demo.dart

@@ -334,7 +334,7 @@ class _ExpansionPanelsDemoState extends State<ExpasionPanelsDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(title: new Text('Expansion panels')),
-      body: new ScrollableViewport(
+      body: new SingleChildScrollView(
         child: new Container(
           margin: const EdgeInsets.all(24.0),
           child: new ExpansionPanelList(

examples/flutter_gallery/lib/gallery/demo.dart

@@ -132,7 +132,7 @@ class FullScreenCodeDialogState extends State<FullScreenCodeDialog> {
         child: new CircularProgressIndicator()
       );
     } else {
-      body = new ScrollableViewport(
+      body = new SingleChildScrollView(
         child: new Padding(
           padding: new EdgeInsets.all(16.0),
           child: new RichText(

packages/flutter/lib/src/material/paginated_data_table.dart

@@ -400,7 +400,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
               )
             )
           ),
-          new ScrollableViewport(
+          new SingleChildScrollView(
             scrollDirection: Axis.horizontal,
             child: new DataTable(
               key: _tableKey,

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

@@ -239,21 +239,6 @@ class SliverConstraints extends Constraints {
   /// width of the viewport.
   final double crossAxisExtent;
 
-  Offset get scrollOffsetAsOffset {
-    assert(axisDirection != null);
-    switch (axisDirection) {
-      case AxisDirection.up:
-        return new Offset(0.0, -scrollOffset);
-      case AxisDirection.down:
-        return new Offset(0.0, scrollOffset);
-      case AxisDirection.left:
-        return new Offset(-scrollOffset, 0.0);
-      case AxisDirection.right:
-        return new Offset(scrollOffset, 0.0);
-    }
-    return null;
-  }
-
   Axis get axis => axisDirectionToAxis(axisDirection);
 
   /// Return what the [growthDirection] would be if the [axisDirection] was
@@ -1037,6 +1022,13 @@ abstract class ViewportOffset extends ChangeNotifier {
   ViewportOffset();
   factory ViewportOffset.fixed(double value) = _FixedViewportOffset;
   factory ViewportOffset.zero() = _FixedViewportOffset.zero;
+
+  /// The number of pixels to offset the children in the opposite of the axis direction.
+  ///
+  /// For example, if the axis direction is down, then the pixel value
+  /// represents the number of logical pixels to move the children _up_ the
+  /// screen. Similarly, if the axis direction is left, then the pixels value
+  /// represents the number of logical pixesl to move the children to _right_.
   double get pixels;
 
   /// Called when the viewport's extents are established.

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

@@ -20,6 +20,7 @@ import 'scroll_simulation.dart';
 import 'notification_listener.dart';
 import 'scroll_notification.dart';
 import 'scrollable.dart';
+import 'viewport.dart';
 
 /// Scrolling logic delegate for lists and other unremarkable scrollable
 /// viewports.
@@ -77,6 +78,25 @@ class ViewportScrollBehavior extends ScrollBehavior2 {
     return null;
   }
 
+  @override
+  Widget createViewport({
+    Key key,
+    AxisDirection axisDirection: AxisDirection.down,
+    double anchor: 0.0,
+    ViewportOffset offset,
+    Key center,
+    List<Widget> children: const <Widget>[],
+  }) {
+    return new Viewport2(
+      key: key,
+      axisDirection: axisDirection,
+      anchor: anchor,
+      offset: offset,
+      center: center,
+      children: children,
+    );
+  }
+
   @override
   ScrollPosition createScrollPosition(BuildContext context, Scrollable2State state, ScrollPosition oldPosition) {
     switch (getPlatform(context)) {

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

@@ -350,6 +350,15 @@ abstract class ScrollBehavior2 {
 
   Widget wrap(BuildContext context, Widget child, AxisDirection axisDirection);
 
+  Widget createViewport({
+    Key key,
+    AxisDirection axisDirection: AxisDirection.down,
+    double anchor: 0.0,
+    ViewportOffset offset,
+    Key center,
+    List<Widget> children: const <Widget>[],
+  });
+
   /// Returns a new instance of the ScrollPosition class that this
   /// ScrollBehavior2 subclass creates.
   ///
@@ -380,6 +389,48 @@ abstract class ScrollBehavior2 {
   String toString() => '$runtimeType';
 }
 
+abstract class ScrollBehavior2Proxy extends ScrollBehavior2 {
+  ScrollBehavior2Proxy(this.parent) {
+    assert(parent != null);
+  }
+
+  final ScrollBehavior2 parent;
+
+  @override
+  Widget wrap(BuildContext context, Widget child, AxisDirection axisDirection) {
+    return parent.wrap(context, child, axisDirection);
+  }
+
+  @override
+  Widget createViewport({
+    Key key,
+    AxisDirection axisDirection: AxisDirection.down,
+    double anchor: 0.0,
+    ViewportOffset offset,
+    Key center,
+    List<Widget> children: const <Widget>[],
+  }) {
+    return parent.createViewport(
+      key: key,
+      axisDirection: axisDirection,
+      anchor: anchor,
+      offset: offset,
+      center: center,
+      children: children,
+    );
+  }
+
+  @override
+  ScrollPosition createScrollPosition(BuildContext context, Scrollable2State state, ScrollPosition oldPosition) {
+    return parent.createScrollPosition(context, state, oldPosition);
+  }
+
+  @override
+  bool shouldNotify(@checked ScrollBehavior2Proxy oldDelegate) {
+    return parent.shouldNotify(oldDelegate.parent);
+  }
+}
+
 class ScrollConfiguration2 extends InheritedWidget {
   const ScrollConfiguration2({
     Key key,
@@ -440,9 +491,8 @@ class Scrollable2 extends StatefulWidget {
   @override
   Scrollable2State createState() => new Scrollable2State();
 
-  ScrollBehavior2 getScrollBehavior(BuildContext context) {
-    return scrollBehavior
-        ?? ScrollConfiguration2.of(context)
+  static ScrollBehavior2 getScrollBehavior(BuildContext context) {
+    return ScrollConfiguration2.of(context)
         ?? new ViewportScrollBehavior();
   }
 
@@ -495,7 +545,7 @@ class Scrollable2State extends State<Scrollable2> with TickerProviderStateMixin
 
   // only call this from places that will definitely trigger a rebuild
   void _updatePosition() {
-    _scrollBehavior = config.getScrollBehavior(context);
+    _scrollBehavior = config.scrollBehavior ?? Scrollable2.getScrollBehavior(context);
     final ScrollPosition oldPosition = position;
     _position = _scrollBehavior.createScrollPosition(context, this, oldPosition);
     assert(position != null);
@@ -640,7 +690,7 @@ class Scrollable2State extends State<Scrollable2> with TickerProviderStateMixin
       child: new IgnorePointer(
         key: _ignorePointerKey,
         ignoring: _shouldIgnorePointer,
-        child: new Viewport2(
+        child: _scrollBehavior.createViewport(
           key: _viewportKey,
           axisDirection: config.axisDirection,
           anchor: config.anchor,

packages/flutter/lib/src/widgets/single_child_scroll_view.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/rendering.dart';
+
+import 'basic.dart';
+import 'framework.dart';
+import 'scrollable.dart';
+
+class SingleChildScrollView extends StatelessWidget {
+  SingleChildScrollView({
+    Key key,
+    this.scrollDirection: Axis.vertical,
+    this.initialScrollOffset: 0.0,
+    this.child,
+  }) : super(key: key) {
+    assert(scrollDirection != null);
+    assert(initialScrollOffset != null);
+  }
+
+  final Axis scrollDirection;
+
+  final double initialScrollOffset;
+
+  final Widget child;
+
+  AxisDirection _getDirection(BuildContext context) {
+    // TODO(abarth): Consider reading direction.
+    switch (scrollDirection) {
+      case Axis.horizontal:
+        return AxisDirection.right;
+      case Axis.vertical:
+        return AxisDirection.down;
+    }
+    return null;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final ScrollBehavior2 scrollBehavior = new _SingleChildScrollViewBehavior(
+      Scrollable2.getScrollBehavior(context)
+    );
+    return new Scrollable2(
+      axisDirection: _getDirection(context),
+      initialScrollOffset: initialScrollOffset,
+      scrollBehavior: scrollBehavior,
+      children: child == null ? const <Widget>[] : <Widget>[ child ],
+    );
+  }
+}
+
+class _SingleChildScrollViewBehavior extends ScrollBehavior2Proxy {
+  _SingleChildScrollViewBehavior(ScrollBehavior2 parent) : super(parent);
+
+  @override
+  Widget createViewport({
+    Key key,
+    AxisDirection axisDirection: AxisDirection.down,
+    double anchor: 0.0,
+    ViewportOffset offset,
+    Key center,
+    List<Widget> children: const <Widget>[],
+  }) {
+    assert(anchor == 0.0);
+    assert(center == null);
+    assert(children.length <= 1);
+    return new _SingleChildViewport(
+      key: key,
+      axisDirection: axisDirection,
+      offset: offset,
+      child: children.isEmpty ? null : children[0],
+    );
+  }
+}
+
+class _SingleChildViewport extends SingleChildRenderObjectWidget {
+  _SingleChildViewport({
+    Key key,
+    this.axisDirection: AxisDirection.down,
+    this.offset,
+    Widget child,
+  }) : super(key: key, child: child) {
+    assert(axisDirection != null);
+  }
+
+  final AxisDirection axisDirection;
+  final ViewportOffset offset;
+
+  @override
+  _RenderSingleChildViewport createRenderObject(BuildContext context) {
+    return new _RenderSingleChildViewport(
+      axisDirection: axisDirection,
+      offset: offset,
+    );
+  }
+
+  @override
+  void updateRenderObject(BuildContext context, _RenderSingleChildViewport renderObject) {
+    // Order dependency: The offset setter reads the axis direction.
+    renderObject
+      ..axisDirection = axisDirection
+      ..offset = offset;
+  }
+}
+
+class _RenderSingleChildViewport extends RenderBox with RenderObjectWithChildMixin<RenderBox> {
+  _RenderSingleChildViewport({
+    AxisDirection axisDirection: AxisDirection.down,
+    ViewportOffset offset,
+    RenderBox child,
+  }) : _axisDirection = axisDirection,
+       _offset = offset {
+    assert(axisDirection != null);
+    assert(offset != null);
+    this.child = child;
+  }
+
+  AxisDirection get axisDirection => _axisDirection;
+  AxisDirection _axisDirection;
+  set axisDirection(AxisDirection value) {
+    assert(value != null);
+    if (value == _axisDirection)
+      return;
+    _axisDirection = value;
+    markNeedsLayout();
+  }
+
+  Axis get axis => axisDirectionToAxis(axisDirection);
+
+  ViewportOffset get offset => _offset;
+  ViewportOffset _offset;
+  set offset(ViewportOffset value) {
+    assert(value != null);
+    if (value == _offset)
+      return;
+    if (attached)
+      _offset.removeListener(markNeedsLayout);
+    if (_offset.pixels != value.pixels)
+      markNeedsLayout();
+    _offset = value;
+    if (attached)
+      _offset.addListener(markNeedsLayout);
+    // If we already have a size, then we should re-report the dimensions
+    // to the new ViewportOffset. If we don't then we'll report them when
+    // we establish the dimensions later, so don't worry about it now.
+    if (hasSize) {
+      assert(_minScrollExtent != null);
+      assert(_maxScrollExtent != null);
+      assert(_effectiveExtent != null);
+      offset.applyViewportDimension(_effectiveExtent);
+      if (offset.applyContentDimensions(_minScrollExtent, _maxScrollExtent))
+        markNeedsPaint();
+    }
+  }
+
+  @override
+  void setupParentData(RenderObject child) {
+    // We don't actually use the offset argument in BoxParentData, so let's
+    // avoid allocating it at all.
+    if (child.parentData is! ParentData)
+      child.parentData = new ParentData();
+  }
+
+  @override
+  void attach(PipelineOwner owner) {
+    super.attach(owner);
+    _offset.addListener(markNeedsPaint);
+  }
+
+  @override
+  void detach() {
+    _offset.removeListener(markNeedsPaint);
+    super.detach();
+  }
+
+  @override
+  bool get isRepaintBoundary => true;
+
+  double get _effectiveExtent {
+    assert(hasSize);
+    switch (axis) {
+      case Axis.vertical:
+        return size.height;
+      case Axis.horizontal:
+        return size.width;
+    }
+    return null;
+  }
+
+
+  double get _minScrollExtent {
+    assert(hasSize);
+    return 0.0;
+  }
+
+  double get _maxScrollExtent {
+    assert(hasSize);
+    if (child == null)
+      return 0.0;
+    return math.max(0.0, child.size.height - size.height);
+  }
+
+  BoxConstraints _getInnerConstraints(BoxConstraints constraints) {
+    switch (axis) {
+      case Axis.horizontal:
+        return constraints.heightConstraints();
+      case Axis.vertical:
+        return constraints.widthConstraints();
+    }
+    return null;
+  }
+
+  @override
+  double computeMinIntrinsicWidth(double height) {
+    if (child != null)
+      return child.getMinIntrinsicWidth(height);
+    return 0.0;
+  }
+
+  @override
+  double computeMaxIntrinsicWidth(double height) {
+    if (child != null)
+      return child.getMaxIntrinsicWidth(height);
+    return 0.0;
+  }
+
+  @override
+  double computeMinIntrinsicHeight(double width) {
+    if (child != null)
+      return child.getMinIntrinsicHeight(width);
+    return 0.0;
+  }
+
+  @override
+  double computeMaxIntrinsicHeight(double width) {
+    if (child != null)
+      return child.getMaxIntrinsicHeight(width);
+    return 0.0;
+  }
+
+  // We don't override computeDistanceToActualBaseline(), because we
+  // want the default behavior (returning null). Otherwise, as you
+  // scroll, it would shift in its parent if the parent was baseline-aligned,
+  // which makes no sense.
+
+  @override
+  void performLayout() {
+    if (child == null) {
+      size = constraints.smallest;
+    } else {
+      child.layout(_getInnerConstraints(constraints), parentUsesSize: true);
+      size = constraints.constrain(child.size);
+    }
+
+    offset.applyViewportDimension(_effectiveExtent);
+    offset.applyContentDimensions(_minScrollExtent, _maxScrollExtent);
+  }
+
+  Offset get _scrollOffsetAsOffset {
+    assert(axisDirection != null);
+    switch (axisDirection) {
+      case AxisDirection.up:
+        return new Offset(0.0, _offset.pixels);
+      case AxisDirection.down:
+        return new Offset(0.0, -_offset.pixels);
+      case AxisDirection.left:
+        return new Offset(_offset.pixels, 0.0);
+      case AxisDirection.right:
+        return new Offset(-_offset.pixels, 0.0);
+    }
+    return null;
+  }
+
+  bool _shouldClipAtPaintOffset(Offset paintOffset) {
+    assert(child != null);
+    return paintOffset < Offset.zero || !(Offset.zero & size).contains((paintOffset & child.size).bottomRight);
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    if (child != null) {
+      final Offset paintOffset = _scrollOffsetAsOffset;
+
+      void paintContents(PaintingContext context, Offset offset) {
+        context.paintChild(child, offset + paintOffset);
+      }
+
+      if (_shouldClipAtPaintOffset(paintOffset)) {
+        context.pushClipRect(needsCompositing, offset, Point.origin & size, paintContents);
+      } else {
+        paintContents(context, offset);
+      }
+    }
+  }
+
+  @override
+  void applyPaintTransform(RenderBox child, Matrix4 transform) {
+    final Offset paintOffset = _scrollOffsetAsOffset;
+    transform.translate(paintOffset.dx, paintOffset.dy);
+  }
+
+  @override
+  Rect describeApproximatePaintClip(RenderObject child) {
+    if (child != null && _shouldClipAtPaintOffset(_scrollOffsetAsOffset))
+      return Point.origin & size;
+    return null;
+  }
+
+  @override
+  bool hitTestChildren(HitTestResult result, { Point position }) {
+    if (child != null) {
+      final Point transformed = position + -_scrollOffsetAsOffset;
+      return child.hitTest(result, position: transformed);
+    }
+    return false;
+  }
+}

packages/flutter/lib/widgets.dart

@@ -54,6 +54,7 @@ export 'src/widgets/scrollable.dart';
 export 'src/widgets/scrollable_grid.dart';
 export 'src/widgets/scrollable_list.dart';
 export 'src/widgets/semantics_debugger.dart';
+export 'src/widgets/single_child_scroll_view.dart';
 export 'src/widgets/size_changed_layout_notifier.dart';
 export 'src/widgets/status_transitions.dart';
 export 'src/widgets/table.dart';

packages/flutter/test/material/expansion_panel_test.dart

@@ -11,7 +11,7 @@ void main() {
     bool isExpanded;
 
     await tester.pumpWidget(
-      new ScrollableViewport(
+      new SingleChildScrollView(
         child: new ExpansionPanelList(
           expansionCallback: (int _index, bool _isExpanded) {
             index = _index;
@@ -42,7 +42,7 @@ void main() {
 
     // now expand the child panel
     await tester.pumpWidget(
-      new ScrollableViewport(
+      new SingleChildScrollView(
         child: new ExpansionPanelList(
           expansionCallback: (int _index, bool _isExpanded) {
             index = _index;

packages/flutter/test/material/mergeable_material_test.dart

@@ -65,7 +65,7 @@ void main() {
   testWidgets('MergeableMaterial empty', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial()
         )
       )
@@ -78,7 +78,7 @@ void main() {
   testWidgets('MergeableMaterial update slice', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -99,7 +99,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -122,7 +122,7 @@ void main() {
   testWidgets('MergeableMaterial swap slices', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -152,7 +152,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -187,7 +187,7 @@ void main() {
   testWidgets('MergeableMaterial paints shadows', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -215,7 +215,7 @@ void main() {
   testWidgets('MergeableMaterial merge gap', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -249,7 +249,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -288,7 +288,7 @@ void main() {
   testWidgets('MergeableMaterial separate slices', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -318,7 +318,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -360,7 +360,7 @@ void main() {
   testWidgets('MergeableMaterial separate merge seaparate', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -390,7 +390,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -430,7 +430,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -467,7 +467,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -509,7 +509,7 @@ void main() {
   testWidgets('MergeableMaterial insert slice', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -539,7 +539,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -577,7 +577,7 @@ void main() {
   testWidgets('MergeableMaterial remove slice', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -614,7 +614,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -646,7 +646,7 @@ void main() {
   testWidgets('MergeableMaterial insert chunk', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -676,7 +676,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -730,7 +730,7 @@ void main() {
   testWidgets('MergeableMaterial remove chunk', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -775,7 +775,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -814,7 +814,7 @@ void main() {
   testWidgets('MergeableMaterial replace gap with chunk', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -848,7 +848,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -902,7 +902,7 @@ void main() {
   testWidgets('MergeableMaterial replace chunk with gap', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -947,7 +947,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             children: <MergeableMaterialItem>[
               new MaterialSlice(
@@ -1001,7 +1001,7 @@ void main() {
   testWidgets('MergeableMaterial dividers', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             hasDividers: true,
             children: <MergeableMaterialItem>[
@@ -1049,7 +1049,7 @@ void main() {
 
     await tester.pumpWidget(
       new Scaffold(
-        body: new ScrollableViewport(
+        body: new SingleChildScrollView(
           child: new MergeableMaterial(
             hasDividers: true,
             children: <MergeableMaterialItem>[

packages/flutter/test/material/scaffold_test.dart

@@ -244,7 +244,7 @@ void main() {
     await tester.pumpWidget(
       new MaterialApp(
         home: new Scaffold(
-          body: new ScrollableViewport(
+          body: new SingleChildScrollView(
             child: new Container(
               decoration: new BoxDecoration(
                 backgroundColor: Colors.amber[500],

packages/flutter/test/rendering/slivers_helpers_test.dart

@@ -31,7 +31,6 @@ void main() {
     expect(a.hashCode, equals(b.hashCode));
     expect(a.toString(), equals(b.toString()));
     expect(a, hasOneLineDescription);
-    expect(a.scrollOffsetAsOffset, equals(const Offset(0.0, 0.0)));
     expect(a.normalizedGrowthDirection, equals(GrowthDirection.forward));
 
     SliverConstraints c = a.copyWith(
@@ -53,21 +52,16 @@ void main() {
       crossAxisExtent: 40.0,
     );
     expect(c, equals(d));
-    expect(c.scrollOffsetAsOffset, equals(const Offset(0.0, -10.0)));
     expect(c.normalizedGrowthDirection, equals(GrowthDirection.forward));
-    expect(d.scrollOffsetAsOffset, equals(const Offset(0.0, -10.0)));
     expect(d.normalizedGrowthDirection, equals(GrowthDirection.forward));
 
     SliverConstraints e = d.copyWith(axisDirection: AxisDirection.right);
-    expect(e.scrollOffsetAsOffset, equals(const Offset(10.0, 0.0)));
     expect(e.normalizedGrowthDirection, equals(GrowthDirection.reverse));
 
     SliverConstraints f = d.copyWith(axisDirection: AxisDirection.left);
-    expect(f.scrollOffsetAsOffset, equals(const Offset(-10.0, 0.0)));
     expect(f.normalizedGrowthDirection, equals(GrowthDirection.forward));
 
     SliverConstraints g = d.copyWith(growthDirection: GrowthDirection.forward);
-    expect(g.scrollOffsetAsOffset, equals(const Offset(0.0, -10.0)));
     expect(g.normalizedGrowthDirection, equals(GrowthDirection.reverse));
   });
 

packages/flutter/test/widgets/align_test.dart

@@ -26,7 +26,7 @@ void main() {
   testWidgets('Shrink wraps in finite space', (WidgetTester tester) async {
     GlobalKey alignKey = new GlobalKey();
     await tester.pumpWidget(
-      new ScrollableViewport(
+      new SingleChildScrollView(
         child: new Align(
           key: alignKey,
           child: new Container(

packages/flutter/test/widgets/scrollable_custom_scroll_behavior_test.dart

@@ -71,12 +71,34 @@ class TestScrollPosition extends ScrollPosition {
 class TestScrollBehavior extends ScrollBehavior2 {
   TestScrollBehavior(this.extentMultiplier);
   final double extentMultiplier;
+
   @override
   Widget wrap(BuildContext context, Widget child, AxisDirection axisDirection) => child;
+
+  @override
+  Widget createViewport({
+    Key key,
+    AxisDirection axisDirection: AxisDirection.down,
+    double anchor: 0.0,
+    ViewportOffset offset,
+    Key center,
+    List<Widget> children: const <Widget>[],
+  }) {
+    return new Viewport2(
+      key: key,
+      axisDirection: axisDirection,
+      anchor: anchor,
+      offset: offset,
+      center: center,
+      children: children,
+    );
+  }
+
   @override
   ScrollPosition createScrollPosition(BuildContext context, Scrollable2State state, ScrollPosition oldPosition) {
     return new TestScrollPosition(extentMultiplier, state, ViewportScrollBehavior.defaultScrollTolerances, oldPosition);
   }
+
   @override
   bool shouldNotify(TestScrollBehavior oldDelegate) {
     return extentMultiplier != oldDelegate.extentMultiplier;
@@ -103,4 +125,4 @@ void main() {
     ));
     expect(key.currentState.position.getMetrics().extentInside, 2.0);
   });
-}
\ No newline at end of file
+}

packages/flutter/test/widgets/single_child_scroll_view_test.dart

+// Copyright 2016 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('SingleChildScrollView control test', (WidgetTester tester) async {
+    await tester.pumpWidget(new SingleChildScrollView(
+      child: new Container(
+        height: 2000.0,
+        decoration: const BoxDecoration(
+          backgroundColor: const Color(0xFF00FF00),
+        ),
+      ),
+    ));
+
+    RenderBox box = tester.renderObject(find.byType(Container));
+    expect(box.localToGlobal(Point.origin), equals(Point.origin));
+
+    await tester.scroll(find.byType(SingleChildScrollView), const Offset(-200.0, -200.0));
+
+    expect(box.localToGlobal(Point.origin), equals(const Point(0.0, -200.0)));
+  });
+}