Move animation curves into a Curves namespace

examples/game/test_physics.dart

@@ -67,14 +67,14 @@ class TestBed extends NodeWithSize {
 
     // Animate obstacle
     ActionSequence seq = new ActionSequence([
-      new ActionTween((a) => _obstacle.position = a, new Point(256.0, 800.0), new Point(768.0, 800.0), 1.0, easeInOut),
+      new ActionTween((a) => _obstacle.position = a, new Point(256.0, 800.0), new Point(768.0, 800.0), 1.0, Curves.easeInOut),
-      new ActionTween((a) => _obstacle.position = a, new Point(768.0, 800.0), new Point(256.0, 800.0), 1.0, easeInOut)
+      new ActionTween((a) => _obstacle.position = a, new Point(768.0, 800.0), new Point(256.0, 800.0), 1.0, Curves.easeInOut)
     ]);
     _obstacle.actions.run(new ActionRepeatForever(seq));
 
     seq = new ActionSequence([
-      new ActionTween((a) => _obstacle.scale = a, 1.0, 2.0, 2.0, easeInOut),
+      new ActionTween((a) => _obstacle.scale = a, 1.0, 2.0, 2.0, Curves.easeInOut),
-      new ActionTween((a) => _obstacle.scale = a, 2.0, 1.0, 2.0, easeInOut)
+      new ActionTween((a) => _obstacle.scale = a, 2.0, 1.0, 2.0, Curves.easeInOut)
     ]);
     _obstacle.actions.run(new ActionRepeatForever(seq));
 

examples/widgets/progress_indicator.dart

@@ -17,8 +17,8 @@ class ProgressIndicatorAppState extends State<ProgressIndicatorApp> {
       ..variable = new AnimatedValue<double>(
         0.0,
         end: 1.0,
-        curve: new Interval(0.0, 0.9, curve: ease),
+        curve: new Interval(0.0, 0.9, curve: Curves.ease),
-        reverseCurve: ease
+        reverseCurve: Curves.ease
       );
     valueAnimation.addStatusListener((PerformanceStatus status) {
       if (status == PerformanceStatus.dismissed || status == PerformanceStatus.completed)

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

@@ -29,7 +29,7 @@ class Linear implements Curve {
 
 /// A curve that is 0.0 until start, then curved from 0.0 to 1.0 at end, then 1.0
 class Interval implements Curve {
-  const Interval(this.start, this.end, { this.curve: linear });
+  const Interval(this.start, this.end, { this.curve: Curves.linear });
 
   /// The smallest value for which this interval is 0.0
   final double start;
@@ -153,38 +153,43 @@ class ElasticInOutCurve implements Curve {
   }
 }
 
+/// A collection of common animation curves.
+class Curves {
+  Curves._();
+
   /// A linear animation curve
-const Linear linear = const Linear();
+  static const Linear linear = const Linear();
 
   /// A cubic animation curve that speeds up quickly and ends slowly
-const Cubic ease = const Cubic(0.25, 0.1, 0.25, 1.0);
+  static const Cubic ease = const Cubic(0.25, 0.1, 0.25, 1.0);
 
   /// A cubic animation curve that starts slowly and ends quickly
-const Cubic easeIn = const Cubic(0.42, 0.0, 1.0, 1.0);
+  static const Cubic easeIn = const Cubic(0.42, 0.0, 1.0, 1.0);
 
   /// A cubic animation curve that starts quickly and ends slowly
-const Cubic easeOut = const Cubic(0.0, 0.0, 0.58, 1.0);
+  static const Cubic easeOut = const Cubic(0.0, 0.0, 0.58, 1.0);
 
   /// A cubic animation curve that starts slowly, speeds up, and then and ends slowly
-const Cubic easeInOut = const Cubic(0.42, 0.0, 0.58, 1.0);
+  static const Cubic easeInOut = const Cubic(0.42, 0.0, 0.58, 1.0);
 
   /// An oscillating curve that grows in magnitude
-const BounceInCurve bounceIn = const BounceInCurve();
+  static const BounceInCurve bounceIn = const BounceInCurve();
 
   /// An oscillating curve that first grows and then shrink in magnitude
-const BounceOutCurve bounceOut = const BounceOutCurve();
+  static const BounceOutCurve bounceOut = const BounceOutCurve();
 
   /// An oscillating curve that first grows and then shrink in magnitude
-const BounceInOutCurve bounceInOut = const BounceInOutCurve();
+  static const BounceInOutCurve bounceInOut = const BounceInOutCurve();
 
   /// An oscillating curve that grows in magnitude while overshootings its bounds
-const ElasticInCurve elasticIn = const ElasticInCurve();
+  static const ElasticInCurve elasticIn = const ElasticInCurve();
 
   /// An oscillating curve that shrinks in magnitude while overshootings its bounds
-const ElasticOutCurve elasticOut = const ElasticOutCurve();
+  static const ElasticOutCurve elasticOut = const ElasticOutCurve();
 
   /// An oscillating curve that grows and then shrinks in magnitude while overshootings its bounds
-const ElasticInOutCurve elasticInOut = const ElasticInOutCurve();
+  static const ElasticInOutCurve elasticInOut = const ElasticInOutCurve();
 
   /// A curve that starts quickly and eases into its final position. Over the course of the animation, the object spends more time near its final destination. As a result, the user isn’t left waiting for the animation to finish, and the negative effects of motion are minimized.
-const Curve fastOutSlowIn = const Cubic(0.4, 0.0, 0.2, 1.0);
+  static const Curve fastOutSlowIn = const Cubic(0.4, 0.0, 0.2, 1.0);
+}

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

@@ -66,7 +66,7 @@ class SimulationStepper {
   ///
   /// Returns a future that resolves when the timeline stops animating,
   /// typically when the timeline arives at the target value.
-  Future animateTo(double target, { Duration duration, Curve curve: linear }) {
+  Future animateTo(double target, { Duration duration, Curve curve: Curves.linear }) {
     assert(duration > Duration.ZERO);
     assert(!isAnimating);
     return _start(new _TweenSimulation(value, target, duration, curve));

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

@@ -142,7 +142,7 @@ class _DialogRoute extends PerformanceRoute {
   Widget build(NavigatorState navigator, PerformanceView nextRoutePerformance) {
     return new FadeTransition(
       performance: performance,
-      opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: easeOut),
+      opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeOut),
       child: builder(new RouteArguments(navigator: navigator, previousPerformance: this.performance, nextPerformance: nextRoutePerformance))
     );
   }

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

@@ -83,7 +83,7 @@ class _Drawer extends StatelessComponent {
             performance: performance,
             position: new AnimatedValue<Point>(_kClosedPosition, end: _kOpenPosition),
             child: new AnimatedContainer(
-              curve: ease,
+              curve: Curves.ease,
               duration: _kThemeChangeDuration,
               decoration: new BoxDecoration(
                 backgroundColor: Theme.of(context).canvasColor,

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

@@ -28,7 +28,7 @@ class _InkSplash {
   _InkSplash(this.position, this.well) {
     _targetRadius = _getSplashTargetSize(well.size, position);
     _radius = new AnimatedValue<double>(
-        _kSplashInitialSize, end: _targetRadius, curve: easeOut);
+        _kSplashInitialSize, end: _targetRadius, curve: Curves.easeOut);
 
     _performance = new ValuePerformance<double>(
       variable: _radius,

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

@@ -67,7 +67,7 @@ class Material extends StatelessComponent {
     return new DefaultTextStyle(
       style: Theme.of(context).text.body1,
       child: new AnimatedContainer(
-        curve: ease,
+        curve: Curves.ease,
         duration: kThemeChangeDuration,
         decoration: new BoxDecoration(
           backgroundColor: _getBackgroundColor(context),

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

@@ -45,7 +45,7 @@ class _ProgressIndicatorState extends State<ProgressIndicator> {
   void initState() {
     super.initState();
     _performance = new ValuePerformance<double>(
-      variable: new AnimatedValue<double>(0.0, end: 1.0, curve: ease),
+      variable: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.ease),
       duration: const Duration(milliseconds: 1500)
     );
     _performance.addStatusListener((PerformanceStatus status) {

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

@@ -26,9 +26,9 @@ class RadialReaction {
     this.radius,
     Point startPosition
   }) {
-    _outerOpacity = new AnimatedValue<double>(0.0, end: _kMaxOpacity, curve: easeOut);
+    _outerOpacity = new AnimatedValue<double>(0.0, end: _kMaxOpacity, curve: Curves.easeOut);
-    _innerCenter = new AnimatedValue<Point>(startPosition, end: center, curve: easeOut);
+    _innerCenter = new AnimatedValue<Point>(startPosition, end: center, curve: Curves.easeOut);
-    _innerRadius = new AnimatedValue<double>(0.0, end: radius, curve: easeOut);
+    _innerRadius = new AnimatedValue<double>(0.0, end: radius, curve: Curves.easeOut);
     _showPerformance = new Performance(duration: _kShowDuration)
       ..addListener(() {
         _showPerformance.updateVariable(_outerOpacity);
@@ -36,7 +36,7 @@ class RadialReaction {
         _showPerformance.updateVariable(_innerRadius);
       });
     _fade = new ValuePerformance<double>(
-      variable: new AnimatedValue<double>(1.0, end: 0.0, curve: easeIn),
+      variable: new AnimatedValue<double>(1.0, end: 0.0, curve: Curves.easeIn),
       duration: _kHideDuration
     );
   }

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

@@ -62,7 +62,7 @@ class ScrollbarPainter extends ScrollableListPainter {
   Future scrollStarted() {
     _fade ??= new ValuePerformance<double>()
       ..duration = _kScrollbarThumbFadeDuration
-      ..variable = new AnimatedValue<double>(0.0, end: 1.0, curve: ease)
+      ..variable = new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.ease)
       ..addListener(() {
         _opacity = _fade.value;
         renderer?.markNeedsPaint();

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

@@ -67,8 +67,8 @@ class SnackBar extends StatelessComponent {
       height: new AnimatedValue<double>(
         0.0,
         end: kSnackBarHeight,
-        curve: easeIn,
+        curve: Curves.easeIn,
-        reverseCurve: easeOut
+        reverseCurve: Curves.easeOut
       ),
       child: new ClipRect(
         child: new OverflowBox(

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

@@ -404,7 +404,7 @@ class _TabBarState extends ScrollableState<TabBar> {
     super.initState();
     _indicatorAnimation = new ValuePerformance<Rect>()
       ..duration = _kTabBarScroll
-      ..variable = new AnimatedRectValue(null, curve: ease);
+      ..variable = new AnimatedRectValue(null, curve: Curves.ease);
     scrollBehavior.isScrollable = config.isScrollable;
   }
 

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

@@ -24,7 +24,7 @@ abstract class RenderToggleable extends RenderConstrainedBox {
         _onChanged = onChanged,
         super(additionalConstraints: new BoxConstraints.tight(size)) {
     _performance = new ValuePerformance<double>(
-      variable: new AnimatedValue<double>(0.0, end: 1.0, curve: easeIn, reverseCurve: easeOut),
+      variable: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeIn, reverseCurve: Curves.easeOut),
       duration: _kToggleDuration,
       progress: _value ? 1.0 : 0.0
     )..addListener(markNeedsPaint);

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

@@ -56,7 +56,7 @@ class AnimatedContainer extends StatefulComponent {
     this.transform,
     this.width,
     this.height,
-    this.curve: linear,
+    this.curve: Curves.linear,
     this.duration
   }) : super(key: key) {
     assert(margin == null || margin.isNonNegative);

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

@@ -13,7 +13,7 @@ import 'gesture_detector.dart';
 
 const Duration _kCardDismissFadeout = const Duration(milliseconds: 200);
 const Duration _kCardDismissResize = const Duration(milliseconds: 300);
-const Curve _kCardDismissResizeCurve = const Interval(0.4, 1.0, curve: ease);
+const Curve _kCardDismissResizeCurve = const Interval(0.4, 1.0, curve: Curves.ease);
 const double _kMinFlingVelocity = 700.0;
 const double _kMinFlingVelocityDelta = 400.0;
 const double _kFlingVelocityScale = 1.0 / 300.0;

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

@@ -307,10 +307,10 @@ class PageRoute extends PerformanceRoute {
     // TODO(jackson): Block input unless content is interactive
     return new SlideTransition(
       performance: performance,
-      position: new AnimatedValue<Point>(_kTransitionStartPoint, end: Point.origin, curve: easeOut),
+      position: new AnimatedValue<Point>(_kTransitionStartPoint, end: Point.origin, curve: Curves.easeOut),
       child: new FadeTransition(
         performance: performance,
-        opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: easeOut),
+        opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeOut),
         child: builder(new RouteArguments(navigator: navigator, previousPerformance: this.performance, nextPerformance: nextRoutePerformance))
       )
     );

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

@@ -181,7 +181,7 @@ abstract class ScrollableState<T extends Scrollable> extends State<T> {
     dispatchOnScroll();
   }
 
-  Future scrollTo(double newScrollOffset, { Duration duration, Curve curve: ease }) {
+  Future scrollTo(double newScrollOffset, { Duration duration, Curve curve: Curves.ease }) {
     if (newScrollOffset == _scrollOffset)
       return new Future.value();
 
@@ -692,7 +692,7 @@ class PageableList<T> extends ScrollableList<T> {
     this.onPageChanged,
     EdgeDims padding,
     this.duration: const Duration(milliseconds: 200),
-    this.curve: ease
+    this.curve: Curves.ease
   }) : super(
     key: key,
     initialScrollOffset: initialPage == null ? null : initialPage * itemExtent,

packages/unit/test/widget/positioned_test.dart

@@ -19,7 +19,7 @@ void main() {
           new Rect.fromLTRB(80.0, 90.0, 90.0, 100.0),
           new Rect.fromLTRB(0.0, 10.0, 100.0, 110.0)
         ),
-        curve: linear
+        curve: Curves.linear
       );
       final Performance performance = new Performance(
         duration: const Duration(seconds: 10)