Clean up imports and exports.

Each layer is supposed to reexport the parts of the previous layer
that are part of its API.

- In painting.dart, export from dart:ui all the Canvas-related APIs
  that make sense to be used at higher levels, e.g. PaintingStyle.

- Delete painting/shadows.dart. It was dead code.

- In rendering/object.dart, export all of painting.dart.

- In widgets/basic.dart, export all of painting.dart and
  animation.dart. Some classes in animation/ are renamed to make this
  less disruptive and confusing to the namespace.

- Split out Stocks back into an import model rather than a part model,
  so that it's easier to manage its dependencies on a per-file basis.

- Move Ticker to scheduler library.

- Remove as many redundant imports as possible now.

- Some minor nit picking cleanup in various files.

examples/fitness/lib/main.dart

@@ -6,7 +6,6 @@ library fitness;
 
 import 'package:playfair/playfair.dart' as playfair;
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
 import 'package:gcm/gcm.dart' as gcm;
 
 import 'user_data.dart';

examples/material_gallery/lib/demo/progress_indicator_demo.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/material.dart';
 
 class ProgressIndicatorDemo extends StatefulComponent {

examples/material_gallery/lib/demo/weathers_demo.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image;
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_sprites/flutter_sprites.dart';

examples/mine_digger/lib/main.dart

@@ -3,10 +3,7 @@
 
 import 'dart:math';
 
-import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 
 // Classic minesweeper-inspired game. The mouse controls are standard

examples/rendering/baseline.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 
 class _BaselinePainter extends CustomPainter {
@@ -29,7 +27,7 @@ class _BaselinePainter extends CustomPainter {
     path.lineTo(w, h);
     paint = new Paint()
      ..color = const Color(0xFFFF9000)
-     ..style = ui.PaintingStyle.stroke
+     ..style = PaintingStyle.stroke
      ..strokeWidth = 1.5;
     canvas.drawPath(path, paint);
 
@@ -39,7 +37,7 @@ class _BaselinePainter extends CustomPainter {
     path.lineTo(w, baseline);
     paint = new Paint()
      ..color = const Color(0xFF00FF90)
-     ..style = ui.PaintingStyle.stroke
+     ..style = PaintingStyle.stroke
      ..strokeWidth = 1.5;
     canvas.drawPath(path, paint);
   }

examples/rendering/borders.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 
 void main() {
@@ -15,7 +13,7 @@ void main() {
           additionalConstraints: new BoxConstraints.tightFor(height: 100.0),
           child: new RenderDecoratedBox(
             decoration: new BoxDecoration(
-              backgroundColor: new ui.Color(0xFFFFFF00)
+              backgroundColor: const Color(0xFFFFFF00)
             )
           )
         )
@@ -27,12 +25,12 @@ void main() {
           child: new RenderDecoratedBox(
             decoration: new BoxDecoration(
               border: new Border(
-                top: new BorderSide(color: new ui.Color(0xFFF00000), width: 5.0),
-                right: new BorderSide(color: new ui.Color(0xFFFF9000), width: 10.0),
-                bottom: new BorderSide(color: new ui.Color(0xFFFFF000), width: 15.0),
-                left: new BorderSide(color: new ui.Color(0xFF00FF00), width: 20.0)
+                top: new BorderSide(color: const Color(0xFFF00000), width: 5.0),
+                right: new BorderSide(color: const Color(0xFFFF9000), width: 10.0),
+                bottom: new BorderSide(color: const Color(0xFFFFF000), width: 15.0),
+                left: new BorderSide(color: const Color(0xFF00FF00), width: 20.0)
               ),
-              backgroundColor: new ui.Color(0xFFDDDDDD)
+              backgroundColor: const Color(0xFFDDDDDD)
             )
           )
         )
@@ -43,7 +41,7 @@ void main() {
           additionalConstraints: new BoxConstraints.tightFor(height: 100.0),
           child: new RenderDecoratedBox(
             decoration: new BoxDecoration(
-              backgroundColor: new ui.Color(0xFFFFFF00)
+              backgroundColor: const Color(0xFFFFFF00)
             )
           )
         )
@@ -54,7 +52,7 @@ void main() {
           additionalConstraints: new BoxConstraints.tightFor(height: 100.0),
           child: new RenderDecoratedBox(
             decoration: new BoxDecoration(
-              backgroundColor: new ui.Color(0xFFFFFF00)
+              backgroundColor: const Color(0xFFFFFF00)
             )
           )
         )
@@ -65,7 +63,7 @@ void main() {
           additionalConstraints: new BoxConstraints.tightFor(height: 100.0),
           child: new RenderDecoratedBox(
             decoration: new BoxDecoration(
-              backgroundColor: new ui.Color(0xFFFFFF00)
+              backgroundColor: const Color(0xFFFFFF00)
             )
           )
         )

examples/rendering/flex.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 import 'lib/solid_color_box.dart';
 
@@ -11,11 +9,11 @@ RenderBox buildFlexExample() {
   RenderFlex flexRoot = new RenderFlex(direction: FlexDirection.vertical);
 
   RenderDecoratedBox root = new RenderDecoratedBox(
-    decoration: new BoxDecoration(backgroundColor: const ui.Color(0xFF000000)),
+    decoration: new BoxDecoration(backgroundColor: const Color(0xFF000000)),
     child: flexRoot
   );
 
-  void addFlexChildSolidColor(RenderFlex parent, ui.Color backgroundColor, { int flex: 0 }) {
+  void addFlexChildSolidColor(RenderFlex parent, Color backgroundColor, { int flex: 0 }) {
     RenderSolidColorBox child = new RenderSolidColorBox(backgroundColor);
     parent.add(child);
     final FlexParentData childParentData = child.parentData;
@@ -23,13 +21,13 @@ RenderBox buildFlexExample() {
   }
 
   // Yellow bar at top
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFFFFFF00), flex: 1);
+  addFlexChildSolidColor(flexRoot, const Color(0xFFFFFF00), flex: 1);
 
   // Turquoise box
-  flexRoot.add(new RenderSolidColorBox(const ui.Color(0x7700FFFF), desiredSize: new ui.Size(100.0, 100.0)));
+  flexRoot.add(new RenderSolidColorBox(const Color(0x7700FFFF), desiredSize: new Size(100.0, 100.0)));
 
   var renderDecoratedBlock = new RenderDecoratedBox(
-    decoration: new BoxDecoration(backgroundColor: const ui.Color(0xFFFFFFFF))
+    decoration: new BoxDecoration(backgroundColor: const Color(0xFFFFFFFF))
   );
 
   flexRoot.add(new RenderPadding(padding: const EdgeDims.all(10.0), child: renderDecoratedBlock));
@@ -37,11 +35,11 @@ RenderBox buildFlexExample() {
   var row = new RenderFlex(direction: FlexDirection.horizontal);
 
   // Purple and blue cells
-  addFlexChildSolidColor(row, const ui.Color(0x77FF00FF), flex: 1);
-  addFlexChildSolidColor(row, const ui.Color(0xFF0000FF), flex: 2);
+  addFlexChildSolidColor(row, const Color(0x77FF00FF), flex: 1);
+  addFlexChildSolidColor(row, const Color(0xFF0000FF), flex: 2);
 
   var decoratedRow = new RenderDecoratedBox(
-    decoration: new BoxDecoration(backgroundColor: const ui.Color(0xFF333333)),
+    decoration: new BoxDecoration(backgroundColor: const Color(0xFF333333)),
     child: row
   );
 

examples/rendering/interactive_flex.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image, window;
 import 'dart:math' as math;
 import 'dart:typed_data';
 

examples/rendering/spinning_flex.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 
 import 'lib/solid_color_box.dart';
@@ -14,16 +12,16 @@ RenderTransform transformBox;
 void main() {
   RenderFlex flexRoot = new RenderFlex(direction: FlexDirection.vertical);
 
-  void addFlexChildSolidColor(RenderFlex parent, ui.Color backgroundColor, { int flex: 0 }) {
+  void addFlexChildSolidColor(RenderFlex parent, Color backgroundColor, { int flex: 0 }) {
     RenderSolidColorBox child = new RenderSolidColorBox(backgroundColor);
     parent.add(child);
     final FlexParentData childParentData = child.parentData;
     childParentData.flex = flex;
   }
 
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFFFF00FF), flex: 1);
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFFFFFF00), flex: 2);
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFF00FFFF), flex: 1);
+  addFlexChildSolidColor(flexRoot, const Color(0xFFFF00FF), flex: 1);
+  addFlexChildSolidColor(flexRoot, const Color(0xFFFFFF00), flex: 2);
+  addFlexChildSolidColor(flexRoot, const Color(0xFF00FFFF), flex: 1);
 
   transformBox = new RenderTransform(child: flexRoot, transform: new Matrix4.identity());
 

examples/rendering/transform.dart

@@ -2,16 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 
 void main() {
   RenderDecoratedBox green = new RenderDecoratedBox(
-    decoration: new BoxDecoration(backgroundColor: const ui.Color(0xFF00FF00))
+    decoration: new BoxDecoration(backgroundColor: const Color(0xFF00FF00))
   );
   RenderConstrainedBox box = new RenderConstrainedBox(
-    additionalConstraints: new BoxConstraints.tight(const ui.Size(200.0, 200.0)),
+    additionalConstraints: new BoxConstraints.tight(const Size(200.0, 200.0)),
     child: green
   );
 

examples/stocks/lib/main.dart

@@ -5,29 +5,18 @@
 library stocks;
 
 import 'dart:async';
-import 'dart:collection';
-import 'dart:math' as math;
-import 'dart:ui' as ui;
 
-import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
-import 'package:flutter/scheduler.dart';
+import 'package:flutter/rendering.dart' show debugPaintSizeEnabled;
 import 'package:intl/intl.dart';
 
-import 'stock_data.dart';
 import 'i18n/stock_messages_all.dart';
-
-part 'stock_arrow.dart';
-part 'stock_home.dart';
-part 'stock_list.dart';
-part 'stock_menu.dart';
-part 'stock_row.dart';
-part 'stock_settings.dart';
-part 'stock_strings.dart';
-part 'stock_symbol_viewer.dart';
-part 'stock_types.dart';
+import 'stock_data.dart';
+import 'stock_home.dart';
+import 'stock_settings.dart';
+import 'stock_strings.dart';
+import 'stock_symbol_viewer.dart';
+import 'stock_types.dart';
 
 class StocksApp extends StatefulComponent {
   StocksAppState createState() => new StocksAppState();
@@ -94,7 +83,7 @@ class StocksAppState extends State<StocksApp> {
     return null;
   }
 
-  Future<LocaleQueryData> _onLocaleChanged(ui.Locale locale) async {
+  Future<LocaleQueryData> _onLocaleChanged(Locale locale) async {
     String localeString = locale.toString();
     await initializeMessages(localeString);
     Intl.defaultLocale = localeString;

examples/stocks/lib/stock_arrow.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'dart:math' as math;
+
+import 'package:flutter/material.dart';
 
 class StockArrowPainter extends CustomPainter {
   StockArrowPainter({ this.color, this.percentChange });
@@ -34,11 +36,11 @@ class StockArrowPainter extends CustomPainter {
     path.lineTo(centerX + w, arrowY + h);
     path.lineTo(centerX - w, arrowY + h);
     path.close();
-    paint.style = ui.PaintingStyle.fill;
+    paint.style = PaintingStyle.fill;
     canvas.drawPath(path, paint);
 
     // Draw a circle that circumscribes the arrow.
-    paint.style = ui.PaintingStyle.stroke;
+    paint.style = PaintingStyle.stroke;
     canvas.drawCircle(new Point(centerX, centerY), r, paint);
   }
 

examples/stocks/lib/stock_home.dart

@@ -2,7 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'dart:collection';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart' show debugDumpRenderTree, debugDumpLayerTree, debugDumpSemanticsTree;
+
+import 'stock_data.dart';
+import 'stock_list.dart';
+import 'stock_menu.dart';
+import 'stock_strings.dart';
+import 'stock_symbol_viewer.dart';
+import 'stock_types.dart';
 
 typedef void ModeUpdater(StockMode mode);
 

examples/stocks/lib/stock_list.dart

@@ -2,7 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'package:flutter/material.dart';
+
+import 'stock_data.dart';
+import 'stock_row.dart';
 
 class StockList extends StatelessComponent {
   StockList({ Key key, this.keySalt, this.stocks, this.onOpen, this.onShow, this.onAction }) : super(key: key);

examples/stocks/lib/stock_menu.dart

@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'dart:async';
+import 'dart:ui' as ui show window;
+
+import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart' show timeDilation;
 
 enum _MenuItems { autorefresh, autorefreshCheckbox, refresh, speedUp, speedDown }
 

examples/stocks/lib/stock_row.dart

@@ -2,7 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'package:flutter/material.dart';
+
+import 'stock_data.dart';
+import 'stock_arrow.dart';
 
 enum StockRowPartKind { arrow }
 

examples/stocks/lib/stock_settings.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'package:flutter/material.dart';
+
+import 'stock_types.dart';
 
 class StockSettings extends StatefulComponent {
   const StockSettings(this.configuration, this.updater);

examples/stocks/lib/stock_strings.dart

-part of stocks;
+// Copyright 2015 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:intl/intl.dart';
+import 'package:flutter/widgets.dart';
 
 // Wrappers for strings that are shown in the UI.  The strings can be
 // translated for different locales using the Dart intl package.

examples/stocks/lib/stock_symbol_viewer.dart

@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
+import 'package:flutter/material.dart';
+
+import 'stock_data.dart';
+import 'stock_arrow.dart';
+import 'stock_row.dart';
 
 class StockSymbolView extends StatelessComponent {
   StockSymbolView({ this.stock });

examples/stocks/lib/stock_types.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of stocks;
-
 enum StockMode { optimistic, pessimistic }
 enum BackupMode { enabled, disabled }
 

examples/widgets/card_collection.dart

@@ -2,11 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
+import 'package:flutter/rendering.dart' show debugDumpRenderTree;
 
 class CardModel {
   CardModel(this.value, this.height) {
@@ -394,7 +391,7 @@ class CardCollectionState extends State<CardCollection> {
     });
   }
 
-  ui.Shader _createShader(Rect bounds) {
+  Shader _createShader(Rect bounds) {
     return new LinearGradient(
         begin: bounds.topLeft,
         end: bounds.bottomLeft,

examples/widgets/drag_and_drop.dart

@@ -3,11 +3,8 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
 
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 
 class ExampleDragTarget extends StatefulComponent {
   ExampleDragTargetState createState() => new ExampleDragTargetState();
@@ -144,7 +141,7 @@ class DashOutlineCirclePainter extends CustomPainter {
     final double radius = size.shortestSide / 2.0;
     final Paint paint = new Paint()
       ..color = const Color(0xFF000000)
-      ..style = ui.PaintingStyle.stroke
+      ..style = PaintingStyle.stroke
       ..strokeWidth = radius / 10.0;
     final Path path = new Path();
     final Rect box = Point.origin & size;

examples/widgets/hero_under.dart

@@ -2,7 +2,7 @@
 // for details. 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:ui' as ui;
+import 'dart:ui' as ui show window;
 
 import 'package:flutter/widgets.dart';
 import 'package:flutter/material.dart';

examples/widgets/mimic_demo.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/material.dart';
 
 const double _kHeight = 150.0;

examples/widgets/nine_patch.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
 void main() {

examples/widgets/overlay_geometry.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
@@ -36,7 +34,7 @@ class _MarkerPainter extends CustomPainter {
 
     paint
       ..color = const Color(0xFFFFFFFF)
-      ..style = ui.PaintingStyle.stroke
+      ..style = PaintingStyle.stroke
       ..strokeWidth = 1.0;
     if (type == MarkerType.topLeft) {
       canvas.drawLine(new Point(r, r), new Point(r + r - 1.0, r), paint);

examples/widgets/pageable_list.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
 
 class CardModel {
   CardModel(this.value, this.size, this.color);

examples/widgets/resolution_awareness.dart

 // Copyright (c) 2016, the Flutter project authors.  Please see the AUTHORS file
 // for details. 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:ui' as ui;
+
+import 'dart:ui' as ui show window;
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';

examples/widgets/smooth_resize.dart

@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart';
 
 final List<Map<int, Color>> _kColors = <Map<int, Color>>[
   Colors.amber,

examples/widgets/spinning_mixed.dart

@@ -2,15 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 
 import 'package:flutter_rendering_examples/solid_color_box.dart';
 
 // Solid colour, RenderObject version
-void addFlexChildSolidColor(RenderFlex parent, ui.Color backgroundColor, { int flex: 0 }) {
+void addFlexChildSolidColor(RenderFlex parent, Color backgroundColor, { int flex: 0 }) {
   RenderSolidColorBox child = new RenderSolidColorBox(backgroundColor);
   parent.add(child);
   FlexParentData childParentData = child.parentData;
@@ -92,9 +90,9 @@ void main() {
   attachWidgetTreeToRenderTree(proxy);
 
   RenderFlex flexRoot = new RenderFlex(direction: FlexDirection.vertical);
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFFFF00FF), flex: 1);
+  addFlexChildSolidColor(flexRoot, const Color(0xFFFF00FF), flex: 1);
   flexRoot.add(proxy);
-  addFlexChildSolidColor(flexRoot, const ui.Color(0xFF0000FF), flex: 1);
+  addFlexChildSolidColor(flexRoot, const Color(0xFF0000FF), flex: 1);
 
   transformBox = new RenderTransform(child: flexRoot, transform: new Matrix4.identity());
   RenderPadding root = new RenderPadding(padding: new EdgeDims.all(80.0), child: transformBox);

packages/flutter/lib/animation.dart

@@ -15,5 +15,4 @@ export 'src/animation/animations.dart';
 export 'src/animation/curves.dart';
 export 'src/animation/forces.dart';
 export 'src/animation/listener_helpers.dart';
-export 'src/animation/ticker.dart';
 export 'src/animation/tween.dart';

packages/flutter/lib/painting.dart

@@ -17,7 +17,6 @@ export 'src/painting/box_painter.dart';
 export 'src/painting/colors.dart';
 export 'src/painting/decoration.dart';
 export 'src/painting/edge_dims.dart';
-export 'src/painting/shadows.dart';
 export 'src/painting/text_editing.dart';
 export 'src/painting/text_painter.dart';
 export 'src/painting/text_style.dart';

packages/flutter/lib/scheduler.dart

@@ -12,3 +12,4 @@
 library scheduler;
 
 export 'src/scheduler/scheduler.dart';
+export 'src/scheduler/ticker.dart';

packages/flutter/lib/src/animation/animation.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' show Color, Size, Rect, VoidCallback, lerpDouble;
+import 'dart:ui' show Color, Size, Rect, VoidCallback;
 
 /// The direction in which an animation is running.
 enum AnimationDirection {

packages/flutter/lib/src/animation/animation_controller.dart

@@ -3,15 +3,15 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:ui' show VoidCallback, lerpDouble;
+import 'dart:ui' as ui show lerpDouble;
 
+import 'package:flutter/scheduler.dart';
 import 'package:newton/newton.dart';
 
 import 'animation.dart';
 import 'curves.dart';
 import 'forces.dart';
 import 'listener_helpers.dart';
-import 'ticker.dart';
 
 /// A controller for an animation.
 ///
@@ -20,7 +20,7 @@ import 'ticker.dart';
 /// bounds of the animation and can drive an animation using a physics
 /// simulation.
 class AnimationController extends Animation<double>
-  with EagerListenerMixin, LocalListenersMixin, LocalAnimationStatusListenersMixin {
+  with AnimationEagerListenerMixin, AnimationLocalListenersMixin, AnimationLocalStatusListenersMixin {
 
   /// Creates an animation controller.
   ///
@@ -257,7 +257,7 @@ class _RepeatingSimulation extends Simulation {
   double x(double timeInSeconds) {
     assert(timeInSeconds >= 0.0);
     final double t = (timeInSeconds / _periodInSeconds) % 1.0;
-    return lerpDouble(min, max, t);
+    return ui.lerpDouble(min, max, t);
   }
 
   double dx(double timeInSeconds) => 1.0;

packages/flutter/lib/src/animation/animations.dart

@@ -63,7 +63,7 @@ class AlwaysStoppedAnimation extends Animation<double> {
 /// Implements most of the [Animation] interface, by deferring its behavior to a
 /// given [parent] Animation. To implement an [Animation] that proxies to a
 /// parent, this class plus implementing "T get value" is all that is necessary.
-abstract class ProxyAnimatedMixin<T> {
+abstract class AnimationWithParentMixin<T> {
   /// The animation whose value this animation will proxy.
   ///
   /// This animation must remain the same for the lifetime of this object. If
@@ -87,7 +87,7 @@ abstract class ProxyAnimatedMixin<T> {
 /// object, and then later change the animation from which the proxy receieves
 /// its value.
 class ProxyAnimation extends Animation<double>
-  with LazyListenerMixin, LocalListenersMixin, LocalAnimationStatusListenersMixin {
+  with AnimationLazyListenerMixin, AnimationLocalListenersMixin, AnimationLocalStatusListenersMixin {
   ProxyAnimation([Animation<double> animation]) {
     _parent = animation;
     if (_parent == null) {
@@ -158,7 +158,7 @@ class ProxyAnimation extends Animation<double>
 /// 0.0 because the tween does not change the status or direction of the
 /// animation.
 class ReverseAnimation extends Animation<double>
-  with LazyListenerMixin, LocalAnimationStatusListenersMixin {
+  with AnimationLazyListenerMixin, AnimationLocalStatusListenersMixin {
   ReverseAnimation(this.parent);
 
   /// The animation whose value and direction this animation is reversing.
@@ -211,7 +211,7 @@ class ReverseAnimation extends Animation<double>
 /// [CurvedAnimation] is useful when you wish to apply a [Curve] and you already
 /// have the underlying animation object. If you don't yet have an animation and
 /// want to apply a [Curve] to a [Tween], consider using [CurveTween].
-class CurvedAnimation extends Animation<double> with ProxyAnimatedMixin<double> {
+class CurvedAnimation extends Animation<double> with AnimationWithParentMixin<double> {
   CurvedAnimation({
     this.parent,
     this.curve: Curves.linear,
@@ -283,7 +283,7 @@ enum _TrainHoppingMode { minimize, maximize }
 /// removed, it exposes a [dispose()] method. Call this method to shut this
 /// object down.
 class TrainHoppingAnimation extends Animation<double>
-  with EagerListenerMixin, LocalListenersMixin, LocalAnimationStatusListenersMixin {
+  with AnimationEagerListenerMixin, AnimationLocalListenersMixin, AnimationLocalStatusListenersMixin {
   TrainHoppingAnimation(this._currentTrain, this._nextTrain, { this.onSwitchedTrain }) {
     assert(_currentTrain != null);
     if (_nextTrain != null) {

packages/flutter/lib/src/animation/listener_helpers.dart

@@ -12,7 +12,7 @@ abstract class _ListenerMixin {
 }
 
 /// A mixin that helps listen to another object only when this object has registered listeners.
-abstract class LazyListenerMixin implements _ListenerMixin {
+abstract class AnimationLazyListenerMixin implements _ListenerMixin {
   int _listenerCounter = 0;
   void didRegisterListener() {
     assert(_listenerCounter >= 0);
@@ -33,7 +33,7 @@ abstract class LazyListenerMixin implements _ListenerMixin {
 
 /// A mixin that replaces the didRegisterListener/didUnregisterListener contract
 /// with a dispose contract.
-abstract class EagerListenerMixin implements _ListenerMixin {
+abstract class AnimationEagerListenerMixin implements _ListenerMixin {
   void didRegisterListener() { }
   void didUnregisterListener() { }
 
@@ -43,7 +43,7 @@ abstract class EagerListenerMixin implements _ListenerMixin {
 
 /// A mixin that implements the addListener/removeListener protocol and notifies
 /// all the registered listeners when notifyListeners is invoked.
-abstract class LocalListenersMixin extends _ListenerMixin {
+abstract class AnimationLocalListenersMixin extends _ListenerMixin {
   final List<VoidCallback> _listeners = <VoidCallback>[];
   void addListener(VoidCallback listener) {
     didRegisterListener();
@@ -63,7 +63,7 @@ abstract class LocalListenersMixin extends _ListenerMixin {
 /// A mixin that implements the addStatusListener/removeStatusListener protocol
 /// and notifies all the registered listeners when notifyStatusListeners is
 /// invoked.
-abstract class LocalAnimationStatusListenersMixin extends _ListenerMixin {
+abstract class AnimationLocalStatusListenersMixin extends _ListenerMixin {
   final List<AnimationStatusListener> _statusListeners = <AnimationStatusListener>[];
   void addStatusListener(AnimationStatusListener listener) {
     didRegisterListener();

packages/flutter/lib/src/animation/tween.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' show Color, Size, Rect, VoidCallback, lerpDouble;
+import 'dart:ui' show Color, Size, Rect, VoidCallback;
 
 import 'animation.dart';
 import 'animations.dart';
@@ -28,7 +28,7 @@ abstract class Animatable<T> {
   }
 }
 
-class _AnimatedEvaluation<T> extends Animation<T> with ProxyAnimatedMixin<double> {
+class _AnimatedEvaluation<T> extends Animation<T> with AnimationWithParentMixin<double> {
   _AnimatedEvaluation(this.parent, this._evaluatable);
 
   /// The animation from which this value is derived.

packages/flutter/lib/src/gestures/binding.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:typed_data';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show window;
 
 import 'package:flutter/services.dart';
 import 'package:mojo/bindings.dart' as mojo_bindings;

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

@@ -4,9 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

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

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Gradient;
 
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
@@ -122,23 +122,24 @@ class _RenderCheckbox extends RenderToggleable {
     // Create an inner rectangle to cover inside of rectangle. This is needed to avoid
     // painting artefacts caused by overlayed paintings.
     Rect innerRect = rect.deflate(1.0);
-    ui.RRect rrect = new ui.RRect.fromRectXY(
-        rect, _kEdgeRadius, _kEdgeRadius);
+    RRect rrect = new RRect.fromRectXY(rect, _kEdgeRadius, _kEdgeRadius);
 
     // Outline of the empty rrect
-    paint.style = ui.PaintingStyle.stroke;
+    paint.style = PaintingStyle.stroke;
     canvas.drawRRect(rrect, paint);
 
     // Radial gradient that changes size
     if (!position.isDismissed) {
       paint
-        ..style = ui.PaintingStyle.fill
+        ..style = PaintingStyle.fill
         ..shader = new ui.Gradient.radial(
           new Point(_kEdgeSize / 2.0, _kEdgeSize / 2.0),
-          _kEdgeSize * (_kMidpoint - position.value) * 8.0, <Color>[
-        const Color(0x00000000),
-        inactiveColor
-      ]);
+          _kEdgeSize * (_kMidpoint - position.value) * 8.0,
+          <Color>[
+            const Color(0x00000000),
+            inactiveColor
+          ]
+        );
       canvas.drawRect(innerRect, paint);
     }
 
@@ -149,24 +150,22 @@ class _RenderCheckbox extends RenderToggleable {
         // First draw a rounded rect outline then fill inner rectangle with the active color
         paint
           ..color = activeColor.withAlpha((t * 255).floor())
-          ..style = ui.PaintingStyle.stroke;
+          ..style = PaintingStyle.stroke;
         canvas.drawRRect(rrect, paint);
-        paint.style = ui.PaintingStyle.fill;
+        paint.style = PaintingStyle.fill;
         canvas.drawRect(innerRect, paint);
       }
 
       // White inner check
       paint
         ..color = const Color(0xFFFFFFFF)
-        ..style = ui.PaintingStyle.stroke;
+        ..style = PaintingStyle.stroke;
       Path path = new Path();
       Point start = new Point(_kEdgeSize * 0.15, _kEdgeSize * 0.45);
       Point mid = new Point(_kEdgeSize * 0.4, _kEdgeSize * 0.7);
       Point end = new Point(_kEdgeSize * 0.85, _kEdgeSize * 0.25);
-      Point lerp(Point p1, Point p2, double t) =>
-          new Point(p1.x * (1.0 - t) + p2.x * t, p1.y * (1.0 - t) + p2.y * t);
-      Point drawStart = lerp(start, mid, 1.0 - t);
-      Point drawEnd = lerp(mid, end, t);
+      Point drawStart = Point.lerp(start, mid, 1.0 - t);
+      Point drawEnd = Point.lerp(mid, end, t);
       path.moveTo(offsetX + drawStart.x, offsetY + drawStart.y);
       path.lineTo(offsetX + mid.x, offsetY + mid.y);
       path.lineTo(offsetX + drawEnd.x, offsetY + drawEnd.y);

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/painting.dart';
 import 'package:flutter/widgets.dart';
 
 import 'constants.dart';

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

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

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

@@ -4,9 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'debug.dart';

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

@@ -4,7 +4,6 @@
 
 import 'dart:math' as math;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'debug.dart';

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'icon_theme.dart';

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

@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show lerpDouble;
+import 'dart:ui' show hashValues;
 
 enum IconThemeColor { white, black }
 
@@ -28,7 +29,7 @@ class IconThemeData {
     return color == typedOther.color && opacity == typedOther.opacity;
   }
 
-  int get hashCode => ui.hashValues(color, opacity);
+  int get hashCode => hashValues(color, opacity);
 
   String toString() => '$color';
 }

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

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:sky_services/editing/editing.mojom.dart' as mojom;
@@ -13,7 +11,6 @@ import 'debug.dart';
 import 'icon.dart';
 import 'theme.dart';
 
-export 'package:flutter/rendering.dart' show ValueChanged;
 export 'package:sky_services/editing/editing.mojom.dart' show KeyboardType;
 
 /// A material design text input field.

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

@@ -4,8 +4,6 @@
 
 import 'dart:math' as math;
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/painting.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 import 'package:vector_math/vector_math_64.dart';

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

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show WindowPadding, window;
 
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
@@ -12,6 +12,8 @@ import 'package:flutter/widgets.dart';
 import 'page.dart';
 import 'theme.dart';
 
+export 'dart:ui' show Locale;
+
 const TextStyle _errorTextStyle = const TextStyle(
   color: const Color(0xD0FF0000),
   fontFamily: 'monospace',
@@ -38,7 +40,7 @@ class RouteArguments {
 }
 typedef Widget RouteBuilder(RouteArguments args);
 
-typedef Future<LocaleQueryData> LocaleChangedCallback(ui.Locale locale);
+typedef Future<LocaleQueryData> LocaleChangedCallback(Locale locale);
 
 class MaterialApp extends StatefulComponent {
   MaterialApp({
@@ -152,7 +154,7 @@ class _MaterialAppState extends State<MaterialApp> implements BindingObserver {
     });
   }
 
-  void didChangeLocale(ui.Locale locale) {
+  void didChangeLocale(Locale locale) {
     if (config.onLocaleChanged != null) {
       config.onLocaleChanged(locale).then((LocaleQueryData data) {
         if (mounted)
@@ -161,7 +163,7 @@ class _MaterialAppState extends State<MaterialApp> implements BindingObserver {
     }
   }
 
-  void didChangeAppLifecycleState(ui.AppLifecycleState state) { }
+  void didChangeAppLifecycleState(AppLifecycleState state) { }
 
   final HeroController _heroController = new HeroController();
 

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

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 class _MaterialPageTransition extends AnimatedComponent {

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

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'ink_well.dart';

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

@@ -3,9 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'theme.dart';
@@ -86,7 +84,7 @@ class _LinearProgressIndicatorPainter extends CustomPainter {
   void paint(Canvas canvas, Size size) {
     Paint paint = new Paint()
       ..color = backgroundColor
-      ..style = ui.PaintingStyle.fill;
+      ..style = PaintingStyle.fill;
     canvas.drawRect(Point.origin & size, paint);
 
     paint.color = valueColor;
@@ -155,7 +153,7 @@ class _CircularProgressIndicatorPainter extends CustomPainter {
     Paint paint = new Paint()
       ..color = valueColor
       ..strokeWidth = _kCircularProgressIndicatorStrokeWidth
-      ..style = ui.PaintingStyle.stroke;
+      ..style = PaintingStyle.stroke;
 
     if (value != null) {
       double angle = value.clamp(0.0, 1.0) * _kSweep;

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

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
@@ -116,13 +114,13 @@ class _RenderRadio extends RenderToggleable {
     // Outer circle
     Paint paint = new Paint()
       ..color = Color.lerp(inactiveColor, radioColor, position.value)
-      ..style = ui.PaintingStyle.stroke
+      ..style = PaintingStyle.stroke
       ..strokeWidth = 2.0;
     canvas.drawCircle(center, _kOuterRadius, paint);
 
     // Inner circle
     if (!position.isDismissed) {
-      paint.style = ui.PaintingStyle.fill;
+      paint.style = PaintingStyle.fill;
       canvas.drawCircle(center, _kInnerRadius * position.value, paint);
     }
   }

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

@@ -6,8 +6,6 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:math' as math;
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'bottom_sheet.dart';

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

@@ -4,8 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 const double _kMinScrollbarThumbLength = 18.0;

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

@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
-import 'package:flutter/painting.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'flat_button.dart';

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

@@ -2,10 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
 import 'package:flutter/gestures.dart';
-import 'package:flutter/painting.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
@@ -194,13 +191,13 @@ class _RenderSwitch extends RenderToggleable {
       size.width - 2.0 * trackHorizontalPadding,
       _kTrackHeight
     );
-    ui.RRect trackRRect = new ui.RRect.fromRectXY(
-        trackRect, _kTrackRadius, _kTrackRadius);
+    RRect trackRRect = new RRect.fromRectXY(trackRect, _kTrackRadius, _kTrackRadius);
     canvas.drawRRect(trackRRect, paint);
 
     Offset thumbOffset = new Offset(
       offset.dx + kRadialReactionRadius + position.value * _trackInnerLength,
-      offset.dy + size.height / 2.0);
+      offset.dy + size.height / 2.0
+    );
 
     paintRadialReaction(canvas, thumbOffset);
 

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

@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:math' as math;
 
 import 'package:newton/newton.dart';
-import 'package:flutter/animation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'theme_data.dart';

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

@@ -4,10 +4,7 @@
 
 import 'dart:math' as math;
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
-import 'package:flutter/services.dart';
+import 'package:flutter/services.dart' show HapticFeedbackType, userFeedback;
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

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

@@ -5,9 +5,6 @@
 import 'dart:async';
 import 'dart:math' as math;
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

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

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

packages/flutter/lib/src/painting/basic_types.dart

@@ -3,21 +3,51 @@
 // found in the LICENSE file.
 
 export 'dart:ui' show
+  BlurStyle,
   Canvas,
   Color,
   ColorFilter,
+  FilterQuality,
   FontStyle,
   FontWeight,
+  ImageShader,
+  LayerDrawLooperBuilder,
+  MaskFilter,
   Offset,
   Paint,
+  PaintingStyle,
   Path,
   Point,
+  RRect,
+  RSTransform,
   Rect,
+  Shader,
   Size,
+  StrokeCap,
   TextAlign,
   TextBaseline,
   TextDecoration,
   TextDecorationStyle,
+  TextDirection,
+  TileMode,
+  TransferMode,
+  VertexMode,
   VoidCallback,
   hashValues,
   hashList;
+
+// Intentionally not exported:
+//  - Image, decodeImageFromDataPipe, decodeImageFromList:
+//      We use ui.* to make it very explicit that these are low-level image APIs.
+//      Generally, higher layers provide more reasonable APIs around images.
+//  - lerpDouble:
+//      Hopefully this will eventually become Double.lerp.
+//  - Paragraph, ParagraphBuilder, ParagraphStyle, TextBox:
+//      These are low-level text primitives. Use this package's TextPainter API.
+//  - Picture, PictureRecorder, Scene, SceneBuilder:
+//      These are low-level primitives. Generally, the rendering layer makes these moot.
+//  - Gradient:
+//      Use this package's higher-level Gradient API instead.
+//  - window, WindowPadding
+//      These are generally wrapped by other APIs so we always refer to them directly
+//      as ui.* to avoid making them seem like high-level APIs.

packages/flutter/lib/src/painting/box_painter.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image, Gradient, lerpDouble;
 
 import 'package:flutter/services.dart';
 
@@ -238,7 +238,7 @@ class BoxShadow {
 /// A 2D gradient.
 abstract class Gradient {
   const Gradient();
-  ui.Shader createShader();
+  Shader createShader();
 }
 
 /// A 2D linear gradient.
@@ -248,7 +248,7 @@ class LinearGradient extends Gradient {
     this.end,
     this.colors,
     this.stops,
-    this.tileMode: ui.TileMode.clamp
+    this.tileMode: TileMode.clamp
   });
 
   /// The point at which stop 0.0 of the gradient is placed.
@@ -269,9 +269,9 @@ class LinearGradient extends Gradient {
   final List<double> stops;
 
   /// How this gradient should tile the plane.
-  final ui.TileMode tileMode;
+  final TileMode tileMode;
 
-  ui.Shader createShader() {
+  Shader createShader() {
     return new ui.Gradient.linear(<Point>[begin, end], this.colors, this.stops, this.tileMode);
   }
 
@@ -320,7 +320,7 @@ class RadialGradient extends Gradient {
     this.radius,
     this.colors,
     this.stops,
-    this.tileMode: ui.TileMode.clamp
+    this.tileMode: TileMode.clamp
   });
 
   /// The center of the gradient.
@@ -343,9 +343,9 @@ class RadialGradient extends Gradient {
   final List<double> stops;
 
   /// How this gradient should tile the plane.
-  final ui.TileMode tileMode;
+  final TileMode tileMode;
 
-  ui.Shader createShader() {
+  Shader createShader() {
     return new ui.Gradient.radial(center, radius, colors, stops, tileMode);
   }
 
@@ -869,7 +869,7 @@ class BoxDecoration extends Decoration {
     double shortestSide = rect.shortestSide;
     // In principle, we should use shortestSide / 2.0, but we don't want to
     // run into floating point rounding errors. Instead, we just use
-    // shortestSide and let ui.Canvas do any remaining clamping.
+    // shortestSide and let Canvas do any remaining clamping.
     return borderRadius > shortestSide ? shortestSide : borderRadius;
   }
 
@@ -879,7 +879,7 @@ class BoxDecoration extends Decoration {
     switch (shape) {
       case BoxShape.rectangle:
         if (borderRadius != null) {
-          ui.RRect bounds = new ui.RRect.fromRectXY(Point.origin & size, borderRadius, borderRadius);
+          RRect bounds = new RRect.fromRectXY(Point.origin & size, borderRadius, borderRadius);
           return bounds.contains(position);
         }
         return true;
@@ -938,7 +938,7 @@ class _BoxDecorationPainter extends BoxPainter {
     return hasUniformWidth;
   }
 
-  void _paintBox(ui.Canvas canvas, Rect rect, Paint paint) {
+  void _paintBox(Canvas canvas, Rect rect, Paint paint) {
     switch (_decoration.shape) {
       case BoxShape.circle:
         assert(_decoration.borderRadius == null);
@@ -951,30 +951,30 @@ class _BoxDecorationPainter extends BoxPainter {
           canvas.drawRect(rect, paint);
         } else {
           double radius = _decoration.getEffectiveBorderRadius(rect);
-          canvas.drawRRect(new ui.RRect.fromRectXY(rect, radius, radius), paint);
+          canvas.drawRRect(new RRect.fromRectXY(rect, radius, radius), paint);
         }
         break;
     }
   }
 
-  void _paintShadows(ui.Canvas canvas, Rect rect) {
+  void _paintShadows(Canvas canvas, Rect rect) {
     if (_decoration.boxShadow == null)
       return;
     for (BoxShadow boxShadow in _decoration.boxShadow) {
       final Paint paint = new Paint()
         ..color = boxShadow.color
-        ..maskFilter = new ui.MaskFilter.blur(ui.BlurStyle.normal, boxShadow._blurSigma);
+        ..maskFilter = new MaskFilter.blur(BlurStyle.normal, boxShadow._blurSigma);
       final Rect bounds = rect.shift(boxShadow.offset).inflate(boxShadow.spreadRadius);
       _paintBox(canvas, bounds, paint);
     }
   }
 
-  void _paintBackgroundColor(ui.Canvas canvas, Rect rect) {
+  void _paintBackgroundColor(Canvas canvas, Rect rect) {
     if (_decoration.backgroundColor != null || _decoration.gradient != null)
       _paintBox(canvas, rect, _backgroundPaint);
   }
 
-  void _paintBackgroundImage(ui.Canvas canvas, Rect rect) {
+  void _paintBackgroundImage(Canvas canvas, Rect rect) {
     final BackgroundImage backgroundImage = _decoration.backgroundImage;
     if (backgroundImage == null)
       return;
@@ -993,7 +993,7 @@ class _BoxDecorationPainter extends BoxPainter {
     );
   }
 
-  void _paintBorder(ui.Canvas canvas, Rect rect) {
+  void _paintBorder(Canvas canvas, Rect rect) {
     if (_decoration.border == null)
       return;
 
@@ -1056,19 +1056,19 @@ class _BoxDecorationPainter extends BoxPainter {
     canvas.drawPath(path, paint);
   }
 
-  void _paintBorderWithRadius(ui.Canvas canvas, Rect rect) {
+  void _paintBorderWithRadius(Canvas canvas, Rect rect) {
     assert(_hasUniformBorder);
     assert(_decoration.shape == BoxShape.rectangle);
     Color color = _decoration.border.top.color;
     double width = _decoration.border.top.width;
     double radius = _decoration.getEffectiveBorderRadius(rect);
 
-    ui.RRect outer = new ui.RRect.fromRectXY(rect, radius, radius);
-    ui.RRect inner = new ui.RRect.fromRectXY(rect.deflate(width), radius - width, radius - width);
+    RRect outer = new RRect.fromRectXY(rect, radius, radius);
+    RRect inner = new RRect.fromRectXY(rect.deflate(width), radius - width, radius - width);
     canvas.drawDRRect(outer, inner, new Paint()..color = color);
   }
 
-  void _paintBorderWithCircle(ui.Canvas canvas, Rect rect) {
+  void _paintBorderWithCircle(Canvas canvas, Rect rect) {
     assert(_hasUniformBorder);
     assert(_decoration.shape == BoxShape.circle);
     assert(_decoration.borderRadius == null);
@@ -1078,14 +1078,14 @@ class _BoxDecorationPainter extends BoxPainter {
     Paint paint = new Paint()
       ..color = _decoration.border.top.color
       ..strokeWidth = width
-      ..style = ui.PaintingStyle.stroke;
+      ..style = PaintingStyle.stroke;
     Point center = rect.center;
     double radius = (rect.shortestSide - width) / 2.0;
     canvas.drawCircle(center, radius, paint);
   }
 
   /// Paint the box decoration into the given location on the given canvas
-  void paint(ui.Canvas canvas, Rect rect) {
+  void paint(Canvas canvas, Rect rect) {
     _paintShadows(canvas, rect);
     _paintBackgroundColor(canvas, rect);
     _paintBackgroundImage(canvas, rect);

packages/flutter/lib/src/painting/decoration.dart

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
+import 'basic_types.dart';
 import 'edge_dims.dart';
 
 export 'edge_dims.dart' show EdgeDims;
@@ -16,14 +15,14 @@ abstract class Decoration {
   EdgeDims get padding => null;
   Decoration lerpFrom(Decoration a, double t) => this;
   Decoration lerpTo(Decoration b, double t) => b;
-  bool hitTest(ui.Size size, ui.Point position) => true;
+  bool hitTest(Size size, Point position) => true;
   bool get needsListeners => false;
-  void addChangeListener(ui.VoidCallback listener) { assert(false); }
-  void removeChangeListener(ui.VoidCallback listener) { assert(false); }
+  void addChangeListener(VoidCallback listener) { assert(false); }
+  void removeChangeListener(VoidCallback listener) { assert(false); }
   BoxPainter createBoxPainter();
   String toString([String prefix = '']) => '$prefix$runtimeType';
 }
 
 abstract class BoxPainter {
-  void paint(ui.Canvas canvas, ui.Rect rect);
+  void paint(Canvas canvas, Rect rect);
 }

packages/flutter/lib/src/painting/edge_dims.dart

@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-import 'dart:ui' show hashValues;
+import 'dart:ui' as ui show lerpDouble;
+
+import 'basic_types.dart';
 
 /// An immutable set of offsets in each of the four cardinal directions.
 ///
@@ -50,13 +51,13 @@ class EdgeDims {
   double get vertical => top + bottom;
 
   /// The size that this EdgeDims would occupy with an empty interior.
-  ui.Size get collapsedSize => new ui.Size(horizontal, vertical);
+  Size get collapsedSize => new Size(horizontal, vertical);
 
   /// An EdgeDims with top and bottom as well as left and right flipped.
   EdgeDims get flipped => new EdgeDims.TRBL(bottom, left, top, right);
 
-  ui.Rect inflateRect(ui.Rect rect) {
-    return new ui.Rect.fromLTRB(rect.left - left, rect.top - top, rect.right + right, rect.bottom + bottom);
+  Rect inflateRect(Rect rect) {
+    return new Rect.fromLTRB(rect.left - left, rect.top - top, rect.right + right, rect.bottom + bottom);
   }
 
   EdgeDims operator -(EdgeDims other) {

packages/flutter/lib/src/painting/shadows.dart

-// Copyright 2015 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:ui' as ui;
-
-/// A helper class to build a [ui.DrawLooper] for drawing shadows
-class ShadowDrawLooperBuilder {
-  ui.LayerDrawLooperBuilder _builder = new ui.LayerDrawLooperBuilder();
-
-  /// Adds a shadow with the given parameters.
-  void addShadow(ui.Offset offset, ui.Color color, double blur) {
-    _builder.addLayerOnTop(
-      new ui.DrawLooperLayerInfo()
-        ..setPaintBits(ui.PaintBits.all)
-        ..setOffset(offset)
-        ..setColorMode(ui.TransferMode.src),
-      new ui.Paint()
-        ..color = color
-        ..maskFilter = new ui.MaskFilter.blur(ui.BlurStyle.normal, blur)
-    );
-  }
-
-  /// Returns the draw looper built for the added shadows
-  ui.DrawLooper build() {
-    _builder.addLayerOnTop(new ui.DrawLooperLayerInfo(), new ui.Paint());
-    return _builder.build();
-  }
-}

packages/flutter/lib/src/painting/text_painter.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphStyle, TextBox;
 
 import 'basic_types.dart';
 import 'text_editing.dart';
@@ -212,7 +212,7 @@ class TextPainter {
   }
 
   /// Paints the text onto the given canvas at the given offset.
-  void paint(ui.Canvas canvas, ui.Offset offset) {
+  void paint(Canvas canvas, Offset offset) {
     assert(!_needsLayout && "Please call layout() before paint() to position the text before painting it." is String);
     _paragraph.paint(canvas, offset);
   }
@@ -223,7 +223,7 @@ class TextPainter {
       return null;
     ui.TextBox box = boxes[0];
     double caretEnd = box.end;
-    double dx = box.direction == ui.TextDirection.rtl ? caretEnd : caretEnd - caretPrototype.width;
+    double dx = box.direction == TextDirection.rtl ? caretEnd : caretEnd - caretPrototype.width;
     return new Offset(dx, 0.0);
   }
 
@@ -233,7 +233,7 @@ class TextPainter {
       return null;
     ui.TextBox box = boxes[0];
     double caretStart = box.start;
-    double dx = box.direction == ui.TextDirection.rtl ? caretStart - caretPrototype.width : caretStart;
+    double dx = box.direction == TextDirection.rtl ? caretStart - caretPrototype.width : caretStart;
     return new Offset(dx, 0.0);
   }
 

packages/flutter/lib/src/painting/text_style.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show ParagraphStyle, TextStyle, lerpDouble;
 
 import 'basic_types.dart';
 

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

@@ -2,19 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-export 'dart:ui' show
-  Canvas,
-  Color,
-  ColorFilter,
-  Offset,
-  Paint,
-  Path,
-  Point,
-  Rect,
-  Size,
-  TransferMode,
-  VoidCallback;
-
 typedef void ValueChanged<T>(T value);
 
 /// A BitField over an enum (or other class whose values implement "index").

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

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show window;
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/scheduler.dart';

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

@@ -3,19 +3,15 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
-import 'dart:ui' show hashValues;
+import 'dart:ui' as ui show lerpDouble;
 
 import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
-import 'package:flutter/painting.dart';
 import 'package:vector_math/vector_math_64.dart';
 
 import 'debug.dart';
 import 'object.dart';
 
-export 'package:flutter/painting.dart' show EdgeDims, FractionalOffset, TextBaseline;
-
 // This class should only be used in debug builds
 class _DebugSize extends Size {
   _DebugSize(Size source, this._owner, this._canBeUsedByParent): super.copy(source);
@@ -837,7 +833,7 @@ abstract class RenderBox extends RenderObject {
   void debugPaintSize(PaintingContext context, Offset offset) {
     assert(() {
       Paint paint = new Paint()
-       ..style = ui.PaintingStyle.stroke
+       ..style = PaintingStyle.stroke
        ..strokeWidth = 1.0
        ..color = debugPaintSizeColor;
       context.canvas.drawRect((offset & size).deflate(0.5), paint);
@@ -847,7 +843,7 @@ abstract class RenderBox extends RenderObject {
   void debugPaintBaselines(PaintingContext context, Offset offset) {
     assert(() {
       Paint paint = new Paint()
-       ..style = ui.PaintingStyle.stroke
+       ..style = PaintingStyle.stroke
        ..strokeWidth = 0.25;
       Path path;
       // ideographic baseline

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

@@ -5,7 +5,6 @@
 import 'dart:async';
 import 'dart:convert' show JSON;
 import 'dart:developer' as developer;
-import 'dart:ui' as ui;
 
 import 'package:flutter/painting.dart';
 import 'package:flutter/rendering.dart';
@@ -18,35 +17,35 @@ export 'package:flutter/services.dart' show debugPrint;
 bool debugPaintSizeEnabled = false;
 
 /// The color to use when painting RenderObject bounds.
-ui.Color debugPaintSizeColor = const ui.Color(0xFF00FFFF);
+Color debugPaintSizeColor = const Color(0xFF00FFFF);
 
 /// The color to use when painting some boxes that just add space (e.g. an empty
 /// RenderConstrainedBox or RenderPadding).
-ui.Color debugPaintSpacingColor = const ui.Color(0x90909090);
+Color debugPaintSpacingColor = const Color(0x90909090);
 
 /// The color to use when painting RenderPadding edges.
-ui.Color debugPaintPaddingColor = const ui.Color(0x900090FF);
+Color debugPaintPaddingColor = const Color(0x900090FF);
 
 /// The color to use when painting RenderPadding edges.
-ui.Color debugPaintPaddingInnerEdgeColor = const ui.Color(0xFF0090FF);
+Color debugPaintPaddingInnerEdgeColor = const Color(0xFF0090FF);
 
 /// The color to use when painting the arrows used to show RenderPositionedBox alignment.
-ui.Color debugPaintArrowColor = const ui.Color(0xFFFFFF00);
+Color debugPaintArrowColor = const Color(0xFFFFFF00);
 
 /// Causes each RenderBox to paint a line at each of its baselines.
 bool debugPaintBaselinesEnabled = false;
 
 /// The color to use when painting alphabetic baselines.
-ui.Color debugPaintAlphabeticBaselineColor = const ui.Color(0xFF00FF00);
+Color debugPaintAlphabeticBaselineColor = const Color(0xFF00FF00);
 
 /// The color ot use when painting ideographic baselines.
-ui.Color debugPaintIdeographicBaselineColor = const ui.Color(0xFFFFD000);
+Color debugPaintIdeographicBaselineColor = const Color(0xFFFFD000);
 
 /// Causes each Layer to paint a box around its bounds.
 bool debugPaintLayerBordersEnabled = false;
 
 /// The color to use when painting Layer borders.
-ui.Color debugPaintLayerBordersColor = const ui.Color(0xFFFF9800);
+Color debugPaintLayerBordersColor = const Color(0xFFFF9800);
 
 /// Causes RenderBox objects to flash while they are being tapped.
 bool debugPaintPointersEnabled = false;
@@ -55,7 +54,7 @@ bool debugPaintPointersEnabled = false;
 int debugPaintPointersColorValue = 0x00BBBB;
 
 /// The color to use when painting RenderError boxes in checked mode.
-ui.Color debugErrorBoxColor = const ui.Color(0xFFFF0000);
+Color debugErrorBoxColor = const Color(0xFFFF0000);
 
 /// Overlay a rotating set of colors when repainting layers in checked mode.
 bool debugEnableRepaintRainbox = false;

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

@@ -2,14 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphStyle, TextBox;
 
 import 'package:flutter/gestures.dart';
-import 'package:flutter/painting.dart';
 
+import 'basic_types.dart';
 import 'box.dart';
 import 'object.dart';
-import 'paragraph.dart';
 
 const _kCaretGap = 1.0; // pixels
 const _kCaretHeightOffset = 2.0; // pixels

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

@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
-import 'package:flutter/painting.dart';
+import 'dart:ui' as ui show Image;
 
 import 'box.dart';
 import 'object.dart';

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

@@ -2,16 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Picture, SceneBuilder;
+import 'dart:ui' show Offset;
 
+import 'package:flutter/painting.dart';
 import 'package:vector_math/vector_math_64.dart';
 import 'package:mojo_services/mojo/ui/layouts.mojom.dart' as mojom;
 
-import 'basic_types.dart';
 import 'debug.dart';
 
-export 'basic_types.dart';
-
 /// A composited layer
 ///
 /// During painting, the render tree generates a tree of composited layers that
@@ -317,7 +316,7 @@ class ClipRRectLayer extends ContainerLayer {
   ClipRRectLayer({ this.clipRRect });
 
   /// The rounded-rect to clip in the parent's coordinate system
-  ui.RRect clipRRect;
+  RRect clipRRect;
   // TODO(abarth): Why is the rounded-rect in the parent's coordinate system
   // instead of in the coordinate system of this layer?
 
@@ -403,7 +402,7 @@ class ShaderMaskLayer extends ContainerLayer {
   ShaderMaskLayer({ this.shader, this.maskRect, this.transferMode });
 
   /// The shader to apply to the children.
-  ui.Shader shader;
+  Shader shader;
 
   /// The size of the shader.
   Rect maskRect;

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

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:developer';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show PictureRecorder;
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/painting.dart';
@@ -18,8 +18,8 @@ import 'node.dart';
 import 'semantics.dart';
 import 'binding.dart';
 
-export 'layer.dart';
 export 'package:flutter/gestures.dart' show HitTestEntry, HitTestResult;
+export 'package:flutter/painting.dart';
 
 /// Base class for data associated with a [RenderObject] by its parent.
 ///
@@ -163,7 +163,7 @@ class PaintingContext {
         canvas.drawRect(_paintBounds, new Paint()..color = debugCurrentRepaintColor.toColor());
       if (debugPaintLayerBordersEnabled) {
         Paint paint = new Paint()
-          ..style = ui.PaintingStyle.stroke
+          ..style = PaintingStyle.stroke
           ..strokeWidth = 1.0
           ..color = debugPaintLayerBordersColor;
         canvas.drawRect(_paintBounds, paint);
@@ -223,9 +223,9 @@ class PaintingContext {
   /// This function will call painter synchronously with a painting context that
   /// is clipped by the given clip. The given clip should not incorporate the
   /// painting offset.
-  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, ui.RRect clipRRect, PaintingContextCallback painter) {
+  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect, PaintingContextCallback painter) {
     Rect offsetBounds = bounds.shift(offset);
-    ui.RRect offsetClipRRect = clipRRect.shift(offset);
+    RRect offsetClipRRect = clipRRect.shift(offset);
     if (needsCompositing) {
       _stopRecordingIfNeeded();
       ClipRRectLayer clipLayer = new ClipRRectLayer(clipRRect: offsetClipRRect);
@@ -305,7 +305,7 @@ class PaintingContext {
   ///
   /// This function will call painter synchronously with a painting context that
   /// will be masked with the given shader.
-  void pushShaderMask(Offset offset, ui.Shader shader, Rect maskRect, TransferMode transferMode, PaintingContextCallback painter) {
+  void pushShaderMask(Offset offset, Shader shader, Rect maskRect, TransferMode transferMode, PaintingContextCallback painter) {
     _stopRecordingIfNeeded();
     ShaderMaskLayer shaderLayer = new ShaderMaskLayer(
       shader: shader,

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

@@ -2,24 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/painting.dart';
-
 import 'box.dart';
 import 'object.dart';
 import 'semantics.dart';
 
-export 'package:flutter/painting.dart' show
-  FontStyle,
-  FontWeight,
-  PlainTextSpan,
-  StyledTextSpan,
-  TextAlign,
-  TextBaseline,
-  TextDecoration,
-  TextDecorationStyle,
-  TextSpan,
-  TextStyle;
-
 /// A render object that displays a paragraph of text
 class RenderParagraph extends RenderBox {
 

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

@@ -2,12 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
-import 'package:flutter/painting.dart';
 import 'package:flutter/gestures.dart';
 import 'package:vector_math/vector_math_64.dart';
 
+import 'basic_types.dart';
 import 'box.dart';
 import 'debug.dart';
 import 'object.dart';
@@ -19,7 +17,6 @@ export 'package:flutter/gestures.dart' show
   PointerMoveEvent,
   PointerUpEvent,
   PointerCancelEvent;
-export 'package:flutter/painting.dart' show Decoration, BoxDecoration;
 
 /// A base class for render objects that resemble their children.
 ///
@@ -642,7 +639,7 @@ class RenderOpacity extends RenderProxyBox {
   }
 }
 
-typedef ui.Shader ShaderCallback(Rect bounds);
+typedef Shader ShaderCallback(Rect bounds);
 
 class RenderShaderMask extends RenderProxyBox {
   RenderShaderMask({ RenderBox child, ShaderCallback shaderCallback, TransferMode transferMode })
@@ -805,7 +802,7 @@ class RenderClipRRect extends RenderProxyBox {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       Rect rect = Point.origin & size;
-      ui.RRect rrect = new ui.RRect.fromRectXY(rect, xRadius, yRadius);
+      RRect rrect = new RRect.fromRectXY(rect, xRadius, yRadius);
       context.pushClipRRect(needsCompositing, offset, rect, rrect, super.paint);
     }
   }

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

@@ -3,9 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
-
-import 'package:flutter/painting.dart';
 
 import 'box.dart';
 import 'debug.dart';
@@ -300,7 +297,7 @@ class RenderPositionedBox extends RenderShiftedBox {
       if (child != null && !child.size.isEmpty) {
         Path path;
         paint = new Paint()
-          ..style = ui.PaintingStyle.stroke
+          ..style = PaintingStyle.stroke
           ..strokeWidth = 1.0
           ..color = debugPaintArrowColor;
         path = new Path();

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

@@ -3,9 +3,8 @@
 // found in the LICENSE file.
 
 import 'dart:developer';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Scene, SceneBuilder, window;
 
-import 'package:flutter/painting.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:vector_math/vector_math_64.dart';
 

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

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show window;
 
 import 'package:vector_math/vector_math_64.dart';
 

packages/flutter/lib/src/scheduler/scheduler.dart

@@ -5,11 +5,14 @@
 import 'dart:async';
 import 'dart:collection';
 import 'dart:developer';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show window;
+import 'dart:ui' show VoidCallback;
 
 import 'package:collection/collection.dart';
 import 'package:flutter/services.dart';
 
+export 'dart:ui' show VoidCallback;
+
 /// Slows down animations by this factor to help in development.
 double timeDilation = 1.0;
 
@@ -32,7 +35,7 @@ SchedulerExceptionHandler debugSchedulerExceptionHandler;
 ///
 /// Combines the task and its priority.
 class _TaskEntry {
-  final ui.VoidCallback task;
+  final VoidCallback task;
   final int priority;
 
   const _TaskEntry(this.task, this.priority);
@@ -110,7 +113,7 @@ abstract class Scheduler extends BindingBase {
   bool _hasRequestedABeginFrameCallback = false;
 
   /// Schedules the given [task] with the given [priority].
-  void scheduleTask(ui.VoidCallback task, Priority priority) {
+  void scheduleTask(VoidCallback task, Priority priority) {
     bool isFirstTask = _taskQueue.isEmpty;
     _taskQueue.add(new _TaskEntry(task, priority._value));
     if (isFirstTask)

packages/flutter/lib/src/animation/ticker.dart → packages/flutter/lib/src/scheduler/ticker.dart

@@ -4,7 +4,7 @@
 
 import 'dart:async';
 
-import 'package:flutter/scheduler.dart';
+import 'scheduler.dart';
 
 typedef TickerCallback(Duration elapsed);
 

packages/flutter/lib/src/services/image_decoder.dart

@@ -4,7 +4,7 @@
 
 import 'dart:async';
 import 'dart:typed_data';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image, decodeImageFromDataPipe, decodeImageFromList;
 
 import 'package:mojo/core.dart' show MojoDataPipeConsumer;
 

packages/flutter/lib/src/services/image_resource.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image;
 
 import 'print.dart';
 

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

@@ -2,72 +2,46 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
+import 'dart:ui' as ui show Image;
 
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 
 import 'framework.dart';
 
+export 'package:flutter/animation.dart';
+export 'package:flutter/painting.dart';
 export 'package:flutter/rendering.dart' show
-    BackgroundImage,
-    Border,
-    BorderSide,
+    Axis,
     BoxConstraints,
-    BoxDecoration,
-    BoxShadow,
-    BoxShape,
-    Canvas,
-    Color,
-    ColorFilter,
     CustomClipper,
     CustomPainter,
-    Decoration,
-    DecorationPosition,
-    EdgeDims,
+    FixedColumnCountGridDelegate,
     FlexAlignItems,
     FlexDirection,
     FlexJustifyContent,
-    FixedColumnCountGridDelegate,
-    FontStyle,
-    FontWeight,
-    FractionalOffset,
-    Gradient,
+    FractionalOffsetTween,
     GridDelegate,
     HitTestBehavior,
-    ImageFit,
-    ImageRepeat,
-    InputEvent,
-    LinearGradient,
-    Matrix4,
     MaxTileWidthGridDelegate,
-    Offset,
+    MultiChildLayoutDelegate,
     OneChildLayoutDelegate,
-    Paint,
-    Path,
+    Painter,
+    PaintingContext,
     PlainTextSpan,
-    Point,
     PointerCancelEvent,
+    PointerCancelEventListener,
     PointerDownEvent,
+    PointerDownEventListener,
     PointerEvent,
     PointerMoveEvent,
+    PointerMoveEventListener,
     PointerUpEvent,
-    RadialGradient,
-    Rect,
-    Axis,
-    Size,
-    StyledTextSpan,
-    TextAlign,
-    TextBaseline,
-    TextDecoration,
-    TextDecorationStyle,
-    TextSpan,
-    TextStyle,
-    TransferMode,
+    PointerUpEventListener,
+    RelativeRect,
+    ShaderCallback,
     ValueChanged,
-    ViewportAnchor,
-    VoidCallback;
-
+    ViewportAnchor;
 
 // PAINTING NODES
 

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

@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
 import 'dart:developer';
+import 'dart:ui' as ui show window;
+import 'dart:ui' show AppLifecycleState, Locale;
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
@@ -12,11 +13,13 @@ import 'package:flutter/services.dart';
 
 import 'framework.dart';
 
+export 'dart:ui' show AppLifecycleState, Locale;
+
 class BindingObserver {
   bool didPopRoute() => false;
   void didChangeMetrics() { }
-  void didChangeLocale(ui.Locale locale) { }
-  void didChangeAppLifecycleState(ui.AppLifecycleState state) { }
+  void didChangeLocale(Locale locale) { }
+  void didChangeAppLifecycleState(AppLifecycleState state) { }
 }
 
 /// A concrete binding for applications based on the Widgets framework.
@@ -69,7 +72,7 @@ class WidgetFlutterBinding extends BindingBase with Scheduler, Gesturer, MojoShe
     dispatchLocaleChanged(ui.window.locale);
   }
 
-  void dispatchLocaleChanged(ui.Locale locale) {
+  void dispatchLocaleChanged(Locale locale) {
     for (BindingObserver observer in _observers)
       observer.didChangeLocale(locale);
   }
@@ -82,7 +85,7 @@ class WidgetFlutterBinding extends BindingBase with Scheduler, Gesturer, MojoShe
     activity.finishCurrentActivity();
   }
 
-  void handleAppLifecycleStateChanged(ui.AppLifecycleState state) {
+  void handleAppLifecycleStateChanged(AppLifecycleState state) {
     for (BindingObserver observer in _observers)
       observer.didChangeAppLifecycleState(state);
   }

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

@@ -3,10 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' as ui;
-
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 
 import 'basic.dart';
 import 'framework.dart';
@@ -37,7 +33,7 @@ class _CheckedModeBannerPainter extends CustomPainter {
   void paint(Canvas canvas, Size size) {
     final Paint paintShadow = new Paint()
       ..color = const Color(0x7F000000)
-      ..maskFilter = new ui.MaskFilter.blur(ui.BlurStyle.normal, kShadowBlur);
+      ..maskFilter = new MaskFilter.blur(BlurStyle.normal, kShadowBlur);
     final Paint paintBanner = new Paint()
       ..color = kColor;
     canvas

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

@@ -2,10 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
-
-import 'package:flutter/animation.dart';
-
 import 'basic.dart';
 import 'transitions.dart';
 import 'framework.dart';
@@ -186,7 +182,7 @@ class _DismissableState extends State<Dismissable> {
       _dismissController.value = _dragExtent.abs() / _size.width;
   }
 
-  bool _isFlingGesture(ui.Offset velocity) {
+  bool _isFlingGesture(Offset velocity) {
     double vx = velocity.dx;
     double vy = velocity.dy;
     if (_directionIsYAxis) {
@@ -215,7 +211,7 @@ class _DismissableState extends State<Dismissable> {
     return false;
   }
 
-  void _handleDragEnd(ui.Offset velocity) {
+  void _handleDragEnd(Offset velocity) {
     if (!_isActive || _dismissController.isAnimating)
       return;
     setState(() {

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

@@ -4,9 +4,8 @@
 
 import 'dart:async';
 
+import 'package:flutter/rendering.dart' show RenderEditableLine;
 import 'package:sky_services/editing/editing.mojom.dart' as mojom;
-import 'package:flutter/painting.dart';
-import 'package:flutter/rendering.dart';
 
 import 'basic.dart';
 import 'framework.dart';

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

@@ -4,8 +4,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
-
 import 'basic.dart';
 import 'framework.dart';
 

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

@@ -8,7 +8,7 @@ import 'dart:collection';
 import 'package:flutter/rendering.dart';
 
 export 'dart:ui' show hashValues, hashList;
-export 'package:flutter/rendering.dart' show debugPrint;
+export 'package:flutter/rendering.dart' show RenderObject, RenderBox, debugPrint;
 
 // KEYS
 

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

@@ -4,8 +4,6 @@
 
 import 'dart:collection';
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 
 import 'basic.dart';

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

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
-
 import 'basic.dart';
 import 'framework.dart';
 

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

@@ -4,8 +4,7 @@
 
 import 'dart:async';
 
-import 'package:flutter/animation.dart';
-import 'package:flutter/rendering.dart';
+import 'package:flutter/rendering.dart' show RenderStack;
 
 import 'basic.dart';
 import 'framework.dart';
@@ -110,7 +109,9 @@ class MimicOverlayEntry {
 
     RenderBox stack = context.ancestorRenderObjectOfType(const TypeMatcher<RenderStack>());
     // TODO(abarth): Handle the case where the transform here isn't just a translation.
-    Point localPosition = stack == null ? globalPosition: stack.globalToLocal(globalPosition);
+    // TODO(ianh): We should probably be getting the overlay's render object rather than looking for a RenderStack.
+    assert(stack != null);
+    Point localPosition = stack.globalToLocal(globalPosition);
     return new Positioned(
       left: localPosition.x,
       top: localPosition.y,

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

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/animation.dart';
-
 import 'basic.dart';
 import 'framework.dart';
 import 'gesture_detector.dart';